Titanium alloys for golf club strikefaces and methods for manufacturing titanium alloys for golf club strikefaces

Abstract

Described herein are embodiments of a golf club having components comprising a metal material with improved durability. The metal material has a solvus temperature between 700° C. and 1050° C. Additionally, the metal material is formed at a temperature that is at least 200° C. below the solvus temperature of the metal material, which results in the metal material being in the sub-solvus state. The metal material in the sub-solvus state has no area fraction greater than 30% for any one of a true pyramidal, true basal, or true prismatic grain orientation.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This claims the benefit of U.S. Provisional Patent Application No. 63 / 825,406 filed on Jun. 17, 2025, and U.S. Provisional Patent Application No. 63 / 755,725 filed on Feb. 7, 2025.TECHNICAL FIELD

[0002] The present disclosure relates generally to golf clubs, and more particular to near alpha titanium alloys, α-β titanium alloys, and near beta titanium alloys for application in golf.BACKGROUND

[0003] The strikeface of a golf club head must be sufficiently durable to withstand repetitive contact with the golf ball. The reaction forces produced at impact generate transferable energy. At the start of impact, the strikeface contacts the golf ball and starts to deflect. Once the strikeface reaches maximum deflection, it inflects and starts to return to the original, undeflected state. As the strikeface returns to an undeflected state, it converts the potential energy stored in the strikeface into kinetic energy that is transferred to the golf ball. The resulting ball speed greatly depends on the efficiency of this energy transfer. Therefore, the strikeface must be sufficiently elastic to deform and regain its original structure at impact to generate ball speed while being sufficiently durable to withstand repeated impacts. Metal alloys, such as titanium alloys, are relatively strong and lightweight, and therefore can be formed relatively thin to generate ball speed while still being sufficiently durable to withstand repeated impacts.

[0004] Certain titanium alloys, such as near alpha alloys, alpha-beta alloys, and near beta alloys, have a unique combination of strength and ductility. The raw material of these titanium alloys have chemical compositions with advantageous mechanical properties for use as strikefaces for golf club heads. However, traditional fabrication processes used to convert the raw material into a final shape deteriorate those mechanical properties. Further, as titanium is naturally anisotropic, titanium structures generally possess directionality, which can be exacerbated by the forming process. Pronounced directionality will strengthen the titanium in one direction while weakening the titanium in another direction, which can reduce suitability of such materials for certain golf club head applications.BRIEF DESCRIPTION OF DRAWINGS

[0005] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee. To facilitate further description of the embodiments, the following drawings are provided in which:

[0006] FIG. 1 illustrates a rear, toe-side perspective view of a golf club head according to the present disclosure.

[0007] FIG. 2 illustrates side a toe-side elevation view of a golf club head according to the present invention, in cross-section.

[0008] FIG. 3 illustrates bottom, plan view of a golf club head according to the present invention.

[0009] FIG. 4 illustrates a detailed, toe-side elevation view of the golf club head according to the present invention, in cross-section.

[0010] FIG. 5 illustrates side a toe-side elevation view of a golf club head according to the present invention, in cross-section.

[0011] FIG. 6 illustrates a toe-side elevation view of a golf club head according to the present invention.

[0012] FIG. 7 illustrates a top, front-side perspective view of a golf club head according to the present invention.

[0013] FIG. 8 illustrates a bottom, front-side perspective view of a golf club head according to the present invention.

[0014] FIG. 9 illustrates a schematic diagram of a metal sheet formed according to the present invention from which are cut a transverse and longitudinal tensile bar.

[0015] FIG. 10 illustrates an EBSD grain orientation map, in the longitudinal direction, for a material according to the present invention in the sub-solvus state.

[0016] FIG. 11 illustrates an EBSD grain orientation map, in the longitudinal direction, for a material in the sub-solvus state according to the present invention.

[0017] FIG. 12 illustrates an EBSD grain orientation map, in the longitudinal direction, for a material in the adjacent solvus state.

[0018] FIG. 13 illustrates an EBSD grain orientation map, in the transverse direction, for a material in the sub-solvus state according to the present invention.

[0019] FIG. 14 illustrates an EBSD grain orientation map, in the transverse direction, for a material in the sub-solvus state according to the present invention.

[0020] FIG. 15 illustrates an EBSD grain orientation map, in the transverse direction, for a material in the adjacent solvus state.

[0021] FIG. 16A illustrates an EBSD grain orientation map, in the transverse direction, for a material in the adjacent solvus state.

[0022] FIG. 16B illustrates an EBSD grain orientation map, in the transverse direction, for a material in the intermediate sub-solvus state.

[0023] FIG. 16C illustrates an EBSD grain orientation map, in the transverse direction, for a material in the deep sub-solvus state.

[0024] FIG. 17 illustrates a graphical depiction of forming temperature vs. yield strength, in the longitudinal direction, for Ti5325.

[0025] FIG. 18 illustrates a graphical depiction of forming temperature vs. elongation, in the longitudinal direction, for Ti5325.

[0026] FIG. 19 illustrates a graphical depiction of forming temperature vs. yield strength, in the transverse direction, for Ti5325.

[0027] FIG. 20 illustrates a graphical depiction of forming temperature vs. elongation, in the transverse direction, for Ti5325.

[0028] FIG. 21 illustrates a graphical depiction of forming temperature vs. yield×elongation, in the longitudinal direction, for Ti5325.

[0029] FIG. 22 illustrates a graphical depiction of forming temperature vs. yield×elongation, in the transverse direction, for Ti5325.

[0030] FIG. 23 illustrates a graphical depiction of forming temperature vs. yield strength, in the longitudinal direction, for 6-22-22.

[0031] FIG. 24 illustrates a graphical depiction of forming temperature vs. yield strength, in the transverse direction, for 6-22-22.

[0032] FIG. 25 illustrates a graphical depiction of forming temperature vs. elongation, in the longitudinal direction, for 6-22-22.

[0033] FIG. 26 illustrates a graphical depiction of forming temperature vs. elongation, in the transverse direction, for 6-22-22.

[0034] FIG. 27 illustrates a graphical depiction of forming temperature vs. yield×elongation, in the longitudinal direction, for 6-22-22.

[0035] FIG. 28 illustrates a graphical depiction of forming temperature vs. yield×elongation, in the transverse direction, for 6-22-22.

[0036] FIG. 29 illustrates a graphical depiction of forming temperature vs. yield strength, in the longitudinal direction, for Ti52AFS.

[0037] FIG. 30 illustrates a graphical depiction of forming temperature vs. elongation, in the longitudinal direction, for Ti52AFS.

[0038] FIG. 31 illustrates a graphical depiction of forming temperature vs. yield strength, in the transverse direction, for Ti52AFS.

[0039] FIG. 32 illustrates a graphical depiction of forming temperature vs. elongation, in the transverse direction, for Ti52AFS.

[0040] For simplicity and clarity of illustration, the drawing figures illustrate the general manner of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the invention. Additionally, elements in the drawing figures are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the present invention. The same reference numerals in different figures denote the same elements.Definitions

[0041] The terms “first,”“second,”“third,”“fourth,” and the like in the description and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms “include,” and “have,” and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, device, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such process, method, system, article, device, or apparatus.

[0042] The terms “left,”“right,”“front,”“back,”“top,”“bottom,”“over,”“under,” and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein.

[0043] The terms “couple,”“coupled,”“couples,”“coupling,” and the like should be broadly understood and refer to directly or indirectly connecting two or more elements or signals, electrically, mechanically and / or otherwise.

[0044] The term “composition,” as described herein, is defined as the kinds and relative count of elements in a material. For alloyed materials, the composition describes the weight percentage of each alloying element within the material. All weight percent (wt %) numbers described below are a total weight percent.

[0045] The term “α stabilizers,” as described herein, is defined as a type of element in a titanium alloy, such as aluminum, oxygen, nitrogen, and carbon. These elements promote the alloy to exist in the α phase at typical ambient temperatures.

[0046] The term “β stabilizers,” as described herein, is defined as a type of element in 25a titanium alloy, such as molybdenum, vanadium, iron, and silicon. These elements promote the alloy to exist in the β phase at typical ambient temperatures.

[0047] The term “near alpha alloy,” as described herein, is defined as an alloy comprising a low amount of β stabilizing elements. Typically, between 1-3 wt % of one or more β stabilizing element.

[0048] The term “alpha-beta alloy,” as described herein, is defined as an alloy comprising approximately 10% beta phase at room temperature.

[0049] The term “near beta alloy,” as described herein, is defined as an alloy comprising approximately 10% to 15% beta phase at room temperature.

[0050] The term “beta alloy,” as described herein, is defined as an alloy containing enough beta-stabilizers to retain its beta phase when quenched to room temperature.

[0051] The term “crystal structure,” as described herein, is defined as the material on the atomic scale and refers to the manner in which atoms or ions are spatially arranged. Crystal structure is defined in terms of unit cell geometry.

[0052] The term “microstructure,” as described herein, is defined as the structural features of a material that can be seen using a microscope. Microstructure includes grain boundaries, grain size, grain shape, dislocations, precipitates, inclusions, pores, voids, and phase structures. These features can seldom be seen with the naked eye.

[0053] The term “crystallographic,” as described herein, is defined as a collection of many repeating crystalline structures all oriented in different directions. Features of the grain structure, such as grain size, grain shape, and grain orientation, can affect the mechanical properties of the material. The size of the grain can affect the strength of the material; wherein smaller gains typically result in stronger materials.

[0054] The term “grain orientation,” as described herein, is defined as having the specific crystallographic alignment of individual crystal lattices (grains) within a polycrystalline material.

[0055] The term “grain boundaries,” as described herein, is defined as the planar defects that occur where two grains meet. Grain boundaries disrupt the motion of dislocations throughout the material, caused by a force applied to the material. The more grain boundaries that are impacted by an external force the less deformation the material will undergo.

[0056] The term “crystallographic texture,” as described herein, is defined as the non-random, directional arrangement of crystals within a polycrystalline material.

[0057] The term “equiaxed,” as described herein, is defined as a grain structure wherein the dimensions in all directions are roughly equal. Essentially, equiaxed grains are approximately equidimensional, having similar lengths, widths, and heights, giving them a roughly spherical or polygonal shape.

[0058] The term “anisotropic,” as described herein, is defined as the mechanical properties of the material having different values when measured in different directions.

[0059] The term “isotropic,” as described herein, is defined as the mechanical properties of the material being approximately the same in all directions.

[0060] The term “stress-strain curve,” as described herein, is defined as to a graphical depiction of the amount of deflection under load for a particular material. Engineering stress is represented on the X-axis of the graph and engineering strain is represented on the Y-axis of the graph.

[0061] The term “engineering stress (S),” as described herein, is defined as the value calculated by dividing the load (P) at any given time by the original cross-sectional area (Ao) of the sample.

[0062] The term “engineering strain (e),” as described herein, is defined as the ratio between the elongation of the gage length (l) of the specimen and the original length (Io).

[0063] The term “rolled material,” as described herein, is defined as the base sheet of material from which front body is cut from.

[0064] The term “tensile strength,” as described herein, is defined as the maximum strength under a tensile or pulling load that a material can absorb without failure. Here, failure is experienced when fracture, snapping, or breakage occurs.

[0065] The term “brittleness,” as described herein, is defined as the failure by sudden fracture, without plastic deformation. Brittleness is further defined as the absence of ductility.

[0066] The “modulus of elasticity” or “Young's Modulus,” as described herein, is defined as the ratio of stress to strain and is the slope (E) of the stress-strain curve in the elastic region. The modulus is used to describe a material's stiffness.

[0067] The term “yield strength” or “proportional limit,” as described herein, is defined as the point on the stress strain curve wherein the material is loaded in tension to the point of permanent, or plastic deformation, such that the deformation remains when the load has been removed.

[0068] The term “spring back” as described herein, is defined as the change is shape (partial reversion back to its original shape) that occurs when a sheet of metal is released from the forming tool after being pressed.

[0069] The term “forming temperature,” as described herein, is defined as the strikeface heating temperature enabling strikeface manipulation to form the VFT and bulge and roll.

[0070] The term “Electron Backscatter Diffraction (EBSD) analysis,” as described herein, is defined as measuring the crystallographic orientation of each grain by determining the misorientation angles between adjacent grains. The misorientation angles represent the angular difference between the crystallographic orientation of adjacent grains.

[0071] The term “Molybdenum Equivalency Equation,” as described herein, is defined as an equation that quantifies the beta-stabilizing effect of alloying elements (like Mo, V, Nb, Cr, Co) in titanium, helping predict properties like the beta solvus temperature and phase stability. The Molybdenum Equivalency Equation yields a Moeq value.

[0072] The term “strikeface,” as described herein, is defined as a club head front surface that is configured to strike a golf ball. The term strikeface can be used interchangeably with the term “face.”

[0073] The term “strikeface perimeter,” as described herein, is defined as an edge of the strikeface. The strikeface perimeter can be located along an outer edge of the strikeface where the curvature deviates from a bulge and / or roll of the strikeface. The strikeface comprises a bulge curvature and a roll curvature. The bulge curvature is the curvature of the strikeface in the heel-to-toe direction. The roll curvature is the curvature of the strikeface in a crown-to-sole direction. The bulge curvature and the roll curvature each respectively comprise a bulge radius and a roll radius defining the radii of curvature associated with each of the bulge curvature and the roll curvature. The bulge curvature and / or the roll curvature can comprise one or more radii.

[0074] An “XYZ” coordinate system of the golf club head, as described herein, is based upon the geometric center of the strikeface. The golf club head dimensions described herein can be measured based on a coordinate system as defined below. The geometric center of the strikeface defines a coordinate system having an origin located at the geometric center of the strikeface. The coordinate system defines an X axis, a Y axis, and a Z axis. The X axis extends through the geometric center of the strikeface in a direction from the heel to the toe of the fairway-type club head. The Y axis extends through the geometric center of the strikeface in a direction from the crown to the sole of golf club head. The Y axis is perpendicular to the X axis. The Z axis extends through the geometric center of the strikeface in a direction from the front end to the rear end of the golf club head. The Z axis is perpendicular to both the X axis and the Y axis.

[0075] The term “geometric centerpoint,” or “geometric center” of the strikeface, as described herein, is defined as a geometric centerpoint of the strikeface perimeter, and at a midpoint of the face height of the strikeface. In the same or other examples, the geometric centerpoint also can be centered with respect to an engineered impact zone, which can be defined by a region of grooves on the strikeface. As another approach, the geometric centerpoint of the strikeface can be located in accordance with the definition of a golf governing body such as the United States Golf Association (USGA)

[0076] The term “transverse direction,” as described herein, refers to a direction on a sheet perpendicular to the roll / grain direction.

[0077] The term “longitudinal direction,” as described herein, is defined as a direction on a sheet parallel to the roll / grain direction.

[0078] The term “adjacent solvus state,” as described herein, is defined as the state the golf club head front body is in after being formed at a temperature between 0° C. and 150° C. below the solvus temperature of the material making up the front body. This state is roughly equivalent to the state achieved by traditional forming processes.

[0079] The term “sub-solvus state,” as described herein, is defined as the state the golf club head front body is in after being formed at a temperature between 150° C. and 325° C. below the solvus temperature of the material making up the front body. The sub-solvus state comprises two sub-states: an intermediate sub-solvus state and a deep sub-solvus state.

[0080] The term “intermediate sub-solvus state,” is defined as the state the golf club head front body is in after being formed at a temperature between 150° C. and 225° C. below the solvus temperature of the material making up the front body.

[0081] The term “deep sub-solvus state,” as described herein, is defined as the state the golf club head front body is in after being formed at a temperature between 225° C. and 325° C. below the solvus temperature of the material making up the front body.

[0082] The term “sub-solvus forming temperature,” as described herein, is defined as the forming temperature that places the golf club head front body is in the sub-solvus state. The sub-solvus forming temperature is between 150° C. and 325° C. below the solvus temperature of the material making up the front body. The sub-solvus forming temperature encompasses both the intermediate sub-solvus forming temperature at 150° C. to 225° C. below the solvus temperature and the deep sub-solvus forming temperature at 225° C. to 325° C.

[0083] The term characteristic time “CT,” as described herein, is defined as a measurement used to determine the amount of time, measured in microseconds (μs), that a golf ball contacts the strikeface at the moment of impact. The characteristic time is measured by impacting a specific spot on the striking surface several times using a small steel pendulum. The characteristic time measurement is for wood-type club heads such as drivers, fairway woods, or hybrids. A computer program measures the amount of time the steel pendulum contacts the strikeface at the moment of impact. CT values were based on the method outlined in the USGA's Procedure for Measuring the Flexibility of a Golf Clubhead. For example, Section 2 of the USGA's Procedure for Measuring the Flexibility of a Golf Clubhead (USGA-TPX3004, Rev. 2.0, Apr. 9, 2019) (the “Protocol For Measuring The Flexibility of A Golf Club Head”).

[0084] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,”“comprising,” and “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. All weight percent (wt %) numbers described below are a total weight percent.

[0085] The general terms used to describe the material properties associated with the disclosed material are provided below. These definitions are regarded as the industry standard and are provided by the professional society of material scientists and material engineers, ASM International.DESCRIPTION

[0086] The golf club heads described herein have a high strength titanium alloy strikeface with a more isotropic crystal structure and more isotropic mechanical properties than conventional strikefaces. The golf club heads have a front body, comprising a strikeface and a return formed of a near alpha alloy, an alpha-beta alloy, or a near beta alloy having a solvus temperature between 700° C. and 1050° C. Forming the front body at a temperature between 150° C. and 325° C. below the solvus temperature, using an increased tonnage to shape the front body, yields a crystalline structure with smaller grain size and reduced directionality compared to materials formed at solvus or adjacent solvus temperatures. Forming at such sub-solvus temperatures require fabrication techniques and equipment capable of applying a magnitude of tonnage not used before to form golf clubs. As the forming temperature is lowered further below the solvus of the metal, the amount of tonnage must be increased. Increasing tonnage and improving other parameters of the forming process (such as tooling) allows the strikeface to be properly formed at a temperature between 150° C. and 325° C. below the solvus temperature. Forming titanium alloys at sub-solvus temperatures as taught herein, creates a more isotropic crystal structure, improving mechanical properties such that alloys previously believed to be unsuitable can now be used in golf applications.

[0087] Titanium is naturally anisotropic and therefore has directionality that can be exacerbated by the forming process. Mitigating directionality in strikefaces is advantageous. Generally, the strikeface experiences higher stress in the crown-to-sole direction than the heel-to-toe direction. The forward portion of both the crown and sole, i.e., the portions that can be made up by the return, experience higher stress in a heel-to-toe direction rather than the crown-to-sole direction. As such, it is desirable to form a front body having both a strikeface and a return with a material having approximately equal mechanical properties in both the crown-to-sole and the heel-to-toe directions. In some embodiments, the mechanical properties may be slightly more desirable (strength and ductility) in one direction (longitudinal or transverse). In such embodiments, the material can be oriented such that the direction having the slightly more desirable mechanical properties extends in the crown-to-sole direction, as the strikeface experiences larger stresses than the return. In one such embodiment the material used to create the front body can be oriented such that the longitudinal direction extends in a crown-to-sole direction. In another such embodiment, the material used to create the front body can be oriented such that the transverse direction extends in a crown-to-sole direction.

[0088] Near alpha alloys, alpha-beta alloys, and near beta alloys advantageously have a strength sufficient to withstand repeated impacts with a golf ball while having a ductility that is sufficiently elastic to provide an efficient energy transfer at impact (i.e., the spring effect) creating high ball speed. The raw material of these alloys has a chemical composition with mechanical properties suitable for use as strikefaces. Traditional fabrication processes used to convert the raw alloy material into a final, net shape, however, significantly deteriorated those mechanical properties. According to the present invention, forming the front body from a near alpha alloy, alpha-beta alloy, or near beta alloy at reduced temperatures, specifically between 150° C. and 325° C. less than the solvus temperature, mitigates that loss and can provide a strikeface that retains up to 98% of the rolled material mechanical properties. Without wanting to be bound by theory, it is believed that forming alloys at sub-solvus temperatures reduce grain size, form more equiaxed grain shapes, and more greatly distributes grain orientation to improve the mechanical properties of the alloy, as described in greater detail below.A. GENERAL DESCRIPTION OF GOLF CLUB HEAD

[0089] A golf club head 100 shown in FIG. 1-8 includes a front body 102 formed from a metal and a rear body 104 formed from metal, composite, or a combination thereof. The rear body 104 can be formed from one or more separately formed composite members 106 and can include one or more weighting members 108 proximate a rear end. The front body 102 and the rear body 104 can form an enclosed hollow interior cavity 110. The golf club head 100 further includes a hosel 101, a crown 112, a sole 114 opposite the crown 112, a heel 116, and a toe 118 opposite the heel 116.

[0090] The front body 102 generally includes a strikeface 122 having a striking surface 123 intended to impact a golf ball, a back surface 124 opposite the striking surface 123, a geometric center 126, an outer edge 128 and a return 130. The back surface 126 borders the enclosed hollow interior cavity 110 of the club head 100. The return 130 can extend rearward from the strikeface 122 such that the return 130 makes up a portion of the crown 112, the sole 114, the heel 116, the toe 118, or a combination of the crown 112 and the sole 114. In some embodiments, as shown in FIGS. 2-3, the return 130 extends rearward from the outer edge 128 to form part the sole 114. In other embodiments, the return 130 can extend rearward from the outer edge 128 to form part of the crown 114. In other embodiments, the return 130 can extend rearward from the outer edge 128 to form both a part of the crown 114 and a part of the sole 114.

[0091] In some embodiments, the return 130 can comprise an impact response modulator 132 (hereafter “JIRM”) monolithically formed with the front body 102. The IRM 132 is positioned in the sole 114 proximate the strikeface 122 to strategically weaken the sole 114, increasing strikeface 122 deflection and improving ball flight performance. The IRM 132 can include a casing that forms one or more walls 134 defining an aperture 136 into the club head 100. The aperture 136 is an opening through the sole 114 that communicates between the environment surrounding the club head 100 and the interior cavity 110 of the club head 100. The IRM 132 further may include an insert 138 positioned within the aperture 136 and formed of a flexible, polymeric material. The above IRM details, are described in U.S. patent application Ser. No. 19 / 090,340, filed on Mar. 25, 2025, U.S. patent application Ser. No. 19 / 212,536, filed on May 19, 2025, U.S. patent application Ser. No. 19 / 255,859, filed on Jun. 30, 2025, and U.S. patent application Ser. No. 19 / 339,232, filed on Sep. 24, 2025, all of which the contents of which are fully incorporated herein.

[0092] The strikeface 122 can define a strikeface thickness measured between the striking surface 123 and the back surface 124 in a direction perpendicular to a loft plane 1015 (FIG. 6). The loft plane 1015 is angled relative to a ground plane 1010. The strikeface 122 can comprise a variable thickness profile. The strikeface 122 can comprise a minimum thickness. The minimum thickness can be between 0.075 inch and 0.125 inch. The minimum thickness can be between 0.075 inch and 0.080 inch, 0.080 inch and 0.085 inch, 0.085 inch and 0.090 inch, 0.090 inch and 0.095 inch, 0.095 inch and 0.100 inch, 0.100 inch 0.105, 0.105 inch and 0.110 inch, 0.110 inch and 0.115 inch, 0.115 inch and 0.120 inch, and 0.120 inch and 0.125 inch. In some embodiments, the minimum thickness can be less than 0.125 inch, less than 0.120 inch, less than 0.115 inch, less than 0.110 inch, less than 0.105 inch, less than 0.100 inch, less than 0.095 inch, less than 0.090 inch, less than 0.085 inch, or less than 0.080 inch. The titanium alloys of the present invention comprise more isotropic mechanical properties due to reduced directionality, created by forming the strikeface at a temperature between 150° C. and 325° C. below the solvus temperature. Accordingly, the thickness of the strikeface can be reduced to increase discretionary mass.

[0093] The center of gravity location, moment of inertia values, and variable face thickness configurations can improve ball speed and related performance characteristics. A thin strikeface 122 can increase discretionary mass, increase ball speed, and improve performance; however, a thinner strikeface 122 typically reduces impacts durability. The front body 102, and therefore the strikeface 122 and the return 130, can be formed from a titanium alloy having a more isotropic crystal structure having smaller, more equiaxed grains and greatly distributed grain orientation. This crystal structure retains the metals rolled mechanical properties that are more equal in the longitudinal and transverse directions. As a result, the finally formed strikeface 122 has mechanical properties that are closer to those of the rolled titanium alloy (higher strength and elasticity). As a result, the thickness of the strikeface 122, can be smaller, saving discretionary mass and improving impact parameters (i.e., providing an improved energy transfer at impact leading to increased ball speed) while maintaining sufficient durability.B. GRAIN ORIENTATION

[0094] A crystal structure of the front body 102 material can affect mechanical properties and therefore durability and fatigue resistance. More specifically, the grain size and grain orientation of each grain relative to adjacent grains can influence the fatigue fracture behavior of the front body 102. A forming temperature between 150° C. and 325° C. below the solvus temperature provides a front body 102 with a crystal structure having a more evenly balanced distribution of both strong and weak orientations, and therefore reduced crystallographic texture and macro-zones. Macro-zones propagate stress, fine line cracks, and overall failure of the strikeface, often at a number of golf ball impact below acceptable standards.

[0095] The front body 102, which was formed at a sub-solvus temperature has a predominant alpha phase, but also includes beta phase. Alpha phase typically exhibits a hexagonal close-packed (HCP) crystal structure that includes true basal planes {0001}, true prismatic planes {1010}, and true pyramidal planes {1120}. True basal planes exhibit strong crystallographic texture in the rolling direction and are associated with high anisotropy, reduced ductility, a higher elastic modulus, and a lower elastic strain capacity. In contrast, true prismatic planes are oriented in a more favorable direction for deformation resulting in a more compliant material response with a lower elastic modulus and larger elastic strain. True pyramidal planes represent grains that are rotated out of the true basal and true prismatic planes. These grains can accommodate even greater elastic strain and, in some cases, promote recovery and recrystallization. Collectively, these planes dictate the material's slip behavior and deformation mechanisms of the material.

[0096] To analyze the crystal structure, both a transverse sample area 200 and a longitudinal sample area 300 can be taken from the front body 102. As shown in FIG. 9, in an exemplary embodiment the transverse sample area 200 is the cross section (cut parallel to surface B) of a transverse tensile bar 202 that extends in a direction perpendicular to the rolling direction (RD). The longitudinal sample area 300 is the cross section (cut parallel to surface C) of a longitudinal tensile bar 302 that extends in a direction parallel to the rolling direction (RD). The aspects of each individual sample area 200, 300 are substantially equivalent across the entirety of the front body 102. As such, each sample area 200, 300 can represent any section of the front body 102 in that respective direction. Each sample area 200, 300 can comprise a height of 56.4 μm and width of 56.4 μm for a sample area of 3181 μm2. Each sample area 200, 300 can comprise a total map resolution of 640,000 pixels within the sample area.

[0097] FIGS. 10-15 depict schematic representations of EBSD (Electron Backscatter Diffraction) analysis of each sample area 200 for an exemplary Ti5325 sample. More specifically, FIGS. 12 and 15 show EBSD analyses of each sample area 200, 300 in an adjacent solvus state, and FIGS. 10-11 and 13-14 show EBSD analyses of the samples in a sub-solvus state. The EBSD images are grain orientation maps illustrating the crystallographic orientations and microstructural features on 2D maps of the surface. The different regions of color depicted in each figure represent a different orientation. According to the present disclosures, the red regions correlates with the true basal orientation, green regions correlate with the true prismatic orientation, and blue regions correlate with the true pyramidal orientation. The EBSD images further comprise intermediate colors. The intermediate colors illustrate orientations that are transitioning between any two of the true orientations. For example, the purple color represents an intermediate orientation between the true basal orientation and the true pyramidal orientation. Intermediate colors include every other color and shade other than true red, true blue, and true green (i.e., light blue, light green, yellow, pink, purple, etc.)

[0098] EBSD images depict the area fraction percentage of each orientation present. Area fraction percentage indicates how much of the scanned area is occupied by grains sharing a specific crystallographic orientation. EBSD images provide a representative 2D section of the material's 3D microstructure. In crystalline materials, the area fraction observed in an EBSD scan reflects the true 3D volume fraction of those orientations. Thus, the color-coded orientation families shown in the EBSD figures not only represent the proportion of the mapped area exhibiting each orientation but also indicate how much of the total material volume contains those orientations. Determining volumetric crystallographic texture content throughout the entire material can be extrapolated from the EBSD area-fraction measurements. Further, in these EBSD figures each color corresponds to one orientation family, and the percentage associated with that color represents the proportion of the total mapped area that exhibits that orientation. This helps quantify how dominant or scarce certain orientations are. Higher area or volume fractions of particular orientations can show preferred grain alignment, while more evenly distributed fractions show a more random or isotropic microstructure.

[0099] FIGS. 10-12, depicts an EBSD analysis for sample area 200. FIGS. 10 and 11 show the EBSD of the material formed at a sub-solvus forming temperature (between 150° C. and 325° C. below the solvus temperature) yielding the sub-solvus state. The grain orientation map of an exemplary front body shows a more balanced distribution of true basal, true prismatic, and true pyramidal orientations, wherein no single orientation of the true basal, true pyramidal, or true prismatic exceeds 30% of the total area fraction. In some embodiments, the total area fraction of each of the true basal, true pyramidal, and true prismatic orientations is less than 15%, 20%, 25%, 35%, 40%, 45%, or 50%. In the sub-solvus state, the true basal orientation percentage (red) is below 30% of the total area fraction. In other embodiments, the true basal orientation percentage is below 5%, below 10%, below 15%, below 20%, below 25%, below 35%, below 40%, below 45%, below 50%, below 55%, or below 60% of the total area fraction. In the deep sub-solvus state, the grains are more equiaxed and uniformly shaped, with no dominant clustering. This combination of grain shape and orientation distribution is indicative of a more isotropic material, with no dominant crystallographic orientation. This absence of crystallographic texture promotes isotropic mechanical behavior, allowing load to be shared evenly among grains. Consequently, both strength and elongation exhibit comparable values in multiple orientations, reflecting the material's overall isotropic response.

[0100] FIG. 10 depicts an EBSD analysis for sample area 200 in the deep sub-solvus state, while FIG. 11 depicts sample area 200 in the intermediate sub-solvus state. A comparison of FIGS. 10 and 11 illustrates how the crystal structure of the material transitions when approaching the solvus temperature. In the intermediate sub-solvus state, partial recovery begins to occur, and the color distribution begins to become less uniform compared to the deep sub-solvus state. The true pyramidal, true basal, and true prismatic orientations are all still present, but their relative fractions begin to shift, and regions of clustering begin to appear. The grains remain more equiaxed, but some early signs of elongation begin to appear, demonstrating a shift to the adjacent solvus state.

[0101] FIG. 12 depicts an EBSD analysis for sample area 200 in the adjacent solvus state, showing the pronounced change in microstructure when compared to the sub-solvus state (FIGS. 10 and 11). In the adjacent solvus state, the microstructure becomes strongly biased towards true basal (red) orientations. In the grain orientation map of an exemplary adjacent solvus state, the true basal percentage (red) is above 60% of the total area fraction. In other embodiments, the true basal percentage is above 40%, above 45%, above 50%, above 55%, above 65%, above 70%, above 75%, above 80%, above 85%, or above 90% of the total area fraction. At the adjacent solvus forming temperature, the grains are elongated and aligned in a banded appearance as shown in FIG. 12. The clustering of alignment and orientation indicates a loss of isotropy and a more directional crystallographic texture. The anisotropic behavior present in the adjacent solvus forming temperature increases directional stiffness and decreases uniformity of mechanical performance of the golf club head. Anisotropy is undesirable for a golf club having a titanium front, strikeface, and adjoining return. The strikeface is subject to higher loading in the crown-to-sole direction than in the heel-to-toe direction, whereas the forward portions of the crown and sole regions (the portions forming the return) experience highest stresses in the heel-to-toe direction. As these regions encounter different principal stress orientations during impact, it is advantageous for the material to exhibit similar mechanical properties in both the crown-to-sole and heel-to-toe directions. As such, a more isotropic material is preferred for the front body of the golf club head to ensure consistent performance across the varying loading conditions experienced during play.

[0102] FIGS. 13-15 depict schematic representations of EBSD analyses for sample area 300. FIGS. 13 and 14 depict the microstructure of the exemplary Ti5325 sample formed at a sub-solvus forming temperature (between 150° C. and 325° C. below the solvus temperature) yielding the sub-solvus state. The grain orientation map of an exemplary front body shows a more balanced distribution of true basal, true prismatic, and true pyramidal orientations, wherein no single orientation of true basal, true pyramidal, or true prismatic orientation exceeds 30% of the total area fraction. In some embodiments, the total area fraction of each of the true basal, true pyramidal, and true prismatic orientations is less than 15%, 20%, 25%, 35%, 40%, 45%, or 50%. In the sub-solvus state, the true pyramidal orientation percentage (blue) is below 30% of the total area fraction. In other embodiments, the true pyramidal orientation percentage is below 5%, below 10%, below 15%, below 20%, below 25%, below 35%, below 40%, below 45%, below 50%, or below 55% of the total area fraction. In the sub-solvus state, the grains are more equiaxed and uniformly shaped, with no dominant clustering. This combination of grain shape and orientation distribution is indicative of a more isotropic material, with no dominant crystallographic orientation.

[0103] FIG. 13 depicts an EBSD analysis for sample area 300 in the deep sub-solvus state, while FIG. 14 depicts sample area 300 in the intermediate sub-solvus state. A comparison of FIGS. 13 and 14 show the crystal structure of the materials transition as it approaches the solvus temperature. At this temperature, partial recovery begins to occur, and the color distribution begins to become less isotropic compared to the deep sub-solvus state. The true pyramidal, true basal, and true prismatic orientations are all still present, but their relative fractions begin to shift, and regions of clustering begin to appear. The grains remain equiaxed, but some early signs of elongation begin to appear, demonstrating a shift to the adjacent solvus state.

[0104] FIG. 15 depicts an EBSD analysis for sample area 300 in the adjacent solvus state, showing the pronounced change in microstructure when compared to the sub-solvus state shown in FIGS. 13 and 14. In the adjacent solvus state, the microstructure becomes strongly biased towards the true pyramidal (blue) orientation. In the grain orientation map of an exemplary adjacent solvus state the true pyramidal percentage (blue) is above 60% of the total area fraction. In other embodiments, the true pyramidal percentage is above 40%, above 45%, above 50%, above 55%, above 65%, above 70%, above 75%, above 80%, above 85%, or above 90% of the total area fraction. At the adjacent solvus forming temperature the grains are elongated and aligned in a banded appearance in FIG. 15. The clustering of alignment and orientation indicates a loss of isotropy and a more directional crystallographic texture. The anisotropic behavior present at the adjacent solvus forming temperature increases directional stiffness and decreases the mechanical performance of the golf club head. For a golf club head incorporating a titanium front body formed from a strikeface and an adjoining return, anisotropy is undesirable. The strikeface is subject to higher loading in the crown-to-sole direction than in the heel-to-toe direction, whereas the forward portions of the crown and sole regions experience the highest stresses in the heel-to-toe direction. As these regions encounter different principal stress orientations during impact, it is advantageous for the material to exhibit similar mechanical properties in both the crown-to-sole and heel-to-toe directions. As such, a more isotropic material is preferred for the front body of the golf club head to ensure consistent performance across the varying loading conditions experienced during play.

[0105] FIG. 12 depicts an EBSD analysis for sample area 200 in the adjacent solvus state, showing the pronounced change in microstructure when compared to the sub-solvus state (FIGS. 10 and 11). In the adjacent solvus state, the microstructure becomes strongly biased towards true basal (red) orientations. In the grain orientation map of an exemplary adjacent solvus state, the true basal percentage (red) is above 60% of the total volume fraction. In other embodiments, the true basal percentage is above 40%, above 45%, above 50%, above 55%, above 65%, above 70%, above 75%, above 80%, above 85%, or above 90% of the total volume fraction. At the adjacent solvus forming temperature, the grains are elongated and aligned in a banded appearance as shown in FIG. 12. The clustering of alignment and orientation indicates a loss of isotropy and a more directional crystallographic texture. The anisotropic behavior present in the adjacent solvus forming temperature increases directional stiffness and decreases uniformity of mechanical performance of the golf club head. Anisotropy is undesirable for a golf club having a titanium front, strikeface, and adjoining return. The strikeface is subject to higher loading in the crown-to-sole direction than in the heel-to-toe direction, whereas the forward portions of the crown and sole regions (the portions forming the return) experience highest stresses in the heel-to-toe direction. As these regions encounter different principal stress orientations during impact, it is advantageous for the material to exhibit similar mechanical properties in both the crown-to-sole and heel-to-toe directions. As such, a more isotropic material is preferred for the front body of the golf club head to ensure consistent performance across the varying loading conditions experienced during play.

[0106] FIGS. 13-15 depict schematic representations of EBSD analyses for sample area 300. FIGS. 13 and 14 depict the microstructure of the exemplary Ti5325 sample formed at a sub-solvus forming temperature (between 150° C. and 325° C. below the solvus temperature) yielding the sub-solvus state. The grain orientation map of an exemplary front body shows a more balanced distribution of true basal, true prismatic, and true pyramidal orientations, wherein no single orientation of true basal, true pyramidal, or true prismatic orientation exceeds 30% of the total volume fraction. In some embodiments, the total volume fraction of each of the true basal, true pyramidal, and true prismatic orientations is less than 15%, 20%, 25%, 35%, 40%, 45%, or 50%. In the sub-solvus state, the true pyramidal orientation percentage (blue) is below 30% of the total volume fraction. In other embodiments, the true pyramidal orientation percentage is below 5%, below 10%, below 15%, below 20%, below 25%, below 35%, below 40%, below 45%, below 50%, or below 55% of the total volume fraction. In the sub-solvus state, the grains are more equiaxed and uniformly shaped, with no dominant clustering. This combination of grain shape and orientation distribution is indicative of a more isotropic material, with no dominant crystallographic orientation.

[0107] FIG. 15 depicts an EBSD analysis for sample area 300 in the adjacent solvus state, showing the pronounced change in microstructure when compared to the sub-solvus state shown in FIGS. 13 and 14. In the adjacent solvus state, the microstructure becomes strongly biased towards the true pyramidal (blue) orientation. In the grain orientation map of an exemplary adjacent solvus state the true pyramidal percentage (blue) is above 60% of the total volume fraction. In other embodiments, the true pyramidal percentage is above 40%, above 45%, above 50%, above 55%, above 65%, above 70%, above 75%, above 80%, above 85%, or above 90% of the total volume fraction. At the adjacent solvus forming temperature the grains are elongated and aligned in a banded appearance in FIG. 15. The clustering of alignment and orientation indicates a loss of isotropy and a more directional crystallographic texture. The anisotropic behavior present at the adjacent solvus forming temperature increases directional stiffness and decreases the mechanical performance of the golf club head. For a golf club head incorporating a titanium front body formed from a strikeface and an adjoining return, anisotropy is undesirable. The strikeface is subject to higher loading in the crown-to-sole direction than in the heel-to-toe direction, whereas the forward portions of the crown and sole regions experience the highest stresses in the heel-to-toe direction. As these regions encounter different principal stress orientations during impact, it is advantageous for the material to exhibit similar mechanical properties in both the crown-to-sole and heel-to-toe directions. As such, a more isotropic material is preferred for the front body of the golf club head to ensure consistent performance across the varying loading conditions experienced during play.C. GRAIN SIZE

[0108] The sample areas 200, 300 further exhibit grain structures that can be depicted as individual grains displayed in a two-dimensional area. Grain size is a metric to analyze the grain structure of metallic materials and may be calculated using standard ASTM grain size measurement guidelines. For golf clubs, small, equiaxed grains provide durability to withstand the stresses of repeated golf ball impacts. Larger grains compromise the integrity of the golf club components, leading to failure in the form of cracking. Specifically, larger grains allow cracks to propagate more easily compared to small grains because there are less grain boundaries to obstruct the propagation of microcracks. The larger grains allow the cracks to follow straighter, more direct paths, accelerating propagation. Conversely, smaller grains obstruct the direct path, making the crack take a more tortuous path that inhibits crack propagation, maintains structural integrity, and improves durability. Therefore, as grain size decreases, mechanical properties, such as ultimate strength and yield strength will increase, relative to the same material having a larger grain structure.

[0109] The forming temperature has a role in determining the grain size of the material. For instance, forming temperatures at or near the solvus temperature of the material (yielding adjacent solvus state) will result in large, elongated grains, while forming at a temperature between 150° C. and 325° C. below the solvus temperature (yielding sub-solvus state) results in relatively small globular grains 142 (i.e., grains with little to no elongation) that are more equiaxed across the sample areas 200, 300. Smaller grains increase yield strength through more boundaries restricting dislocation movement and delaying crack initiation. This in turn increases overall fatigue life. In addition, smaller grains create a more tortuous and longer crack path increasing fatigue life. For a given material, smaller grain sizes in the sub-solvus states can be expressed as a percent grain size reduction compared to larger grain sizes of the adjacent solvus state. Accordingly, a percent grain size reduction is the ratio between the grain size of the sub-solvus state and the grain size of the adjacent solvus state.

[0110] The percent grain size reduction may be applied to the average grain size, median grain size, minimum grain size, and maximum grain size. In some embodiments, the average grain size may comprise a percent grain size reduction below 90%. In other embodiments, the average grain size may comprise a percent grain size reduction below 85%, below 80%, below 75%, below 70%, below 65%, below 60%, below 55%, or below 50%. Further, in some embodiments the average grain size may comprise a percent grain size reduction between 90% and 85%, between 85% and 80%, between 80% and 75%, between 75% and 70%, between 70% and 65%, between 65% and 60%, between 60% and 55%, or between 55% and 50%. The median grain size may comprise a percent grain size reduction below 90%. In other embodiments, the median grain size may comprise a percent grain size reduction below 85%, below 80%, below 75%, below 70%, below 65%, below 60%, below 55%, or below 50%. Further, in some embodiments the median grain size may comprise a percent grain size reduction between 90% and 85%, between 85% and 80%, between 80% and 75%, between 75% and 70%, between 70% and 65%, between 65% and 60%, between 60% and 55%, or between 55% and 50%.

[0111] Decreasing the grain size also results in a higher number of grains per unit area, also known as a grain density. For instance, the number of grains within sample areas 200, 300 can be counted and compared to a baseline value, such as the adjacent solvus state. The adjacent solvus state comprises larger grain sizes, resulting in a lower grain density than the sub-solvus state. For example, in some embodiments, the grain density for an adjacent solvus state may be 0.25 grains per μm2 or lower, while the sub-solvus state comprises a grain density of 0.35 grains per μm2 or higher. Within the sub solvus state the deep sub-solvus state can comprise a grain density of 0.41 grains per μm2 or higher. In these embodiments, the sub-solvus grain density may increase, relative to the adjacent solvus state grain density, by over 100%. In other embodiments, the sub-solvus grain density may increase, relative to the adjacent solvus state grain density, between 40% and 50%, between 50% and 60%, between 60% and 70%, between 70% and 80%, between 80% and 90%, or between 90% and 100%. More grains per unit area results in a larger amount of grain boundaries within the material. This corresponds to increased durability as crack propagation is inhibited by the increased number of grains. Additionally, the smaller and increased number of grains further improves the ultimate strength and yield strength of the material.

[0112] The sample area 200 in the deep sub-solvus embodiment, shown in FIG. 16C, has grains that are more equiaxed in shape. An equiaxed structure produces a material that has equal mechanical properties in all directions. A non-equiaxed grain structure, the result of forming the material at the solvus state, forms a longer column shape, which creates an anisotropic structure, as illustrated in FIG. 16A. This anisotropic structure will have strong and weak directions based on the direction of the columnar grains 140, which for golf club components, i.e., the front body 102 of the present invention, is not desirable. The isotropic, equiaxed structure is beneficial for the front body 102 of the present invention because strength is needed in all directions, due to the sole and / or crown return. The forming temperature of the golf club components influences the grain structure. Specifically, forming at the adjacent solvus state yields a generally non-equiaxed grain structure having columnar grains 140 resulting in a higher crystallographic texture. The non-equiaxed grain structure lacks substantially equal strength in all directions. While materials formed at a temperature between 150° C. and 325° C. below the solvus temperature (yielding sub-solvus state), such as the grain structure depicted in FIG. 16B, has a more equiaxed, globular grain structure. In general, materials formed at a temperature between 150° C. and 325° C. below the solvus temperature yields grain structures with small grains that are more equiaxed, providing improved strength and therefore durability to withstand stresses from repeated golf ball impacts.D. MECHANICAL PROPERTIES

[0113] Generally, the strikeface 122 experiences higher stress in the crown-to-sole direction than the heel to toe direction. However, the forward portion of both the crown and sole, i.e., the portions that can form the return 130, experience higher stress in a heel to toe direction. As such, having approximately equal mechanical properties in both directions can be desirable for a golf club head 100 having a front body 102 formed from a strikeface 122 and a return 130. Further, the golf club head of the present invention can have a front body 102 with mechanical properties close, to if not the same as, that of the rolled material. Materials formed at a temperature between 150° C. and 325° C. below the solvus temperature have greater grain density, leading to improved strength, and balance plane orientation distribution providing a more isotropic material with approximately equal mechanical properties in the transverse and longitudinal direction.

[0114] The strength of a strikeface material, such as titanium alloy, is defined as a relationship between yield strength and elongation. Strength is related to durability, which is quantified by the amount of hits a strikeface can withstand before failure. Generally, a high yield strength, high elongation, and high toughness result in a more durable strikeface. This is because the high yield strength is associated with the ability to withstand stress without breaking, while high elongation allows for a material to withstand more permanent deformation before breaking. Toughness is the materials resistance to fracture without absorbing energy. A low yield strength renders the strikeface unable to withstand repeated stresses of impact with a golf ball, and a strikeface with a low elongation will be too brittle. Another key mechanical property for a strikeface metal, related to yield strength and elongation, is the elasticity modulus, which describes the stiffness of the material. These mechanical properties are important to golf clubs as thinner / lower weight strikefaces allow for more design freedom by creating discretionary mass, but the strikeface must retain durability. Forming the strikeplate material at reduced temperatures, specifically between 150° C. and 325° C. less than the solvus temperature, mitigates the loss of mechanical properties, providing a strikeface with up to 98% of the rolled material mechanical properties.

[0115] The mechanical properties of a golf club strikeface must also result in a strikeface that conforms to the rules of golf. For instance, characteristic time (CT) is an element that relates to energy transfer and is limited by the rules of golf. Higher CT values equate to greater energy transfer, which is why CT is regulated by the rules of golf and monitored when designing new golf clubs. CT is affected by both the structural design and the materials selected for the golf club. For instance, a higher modulus material is stiffer, which generally results in a lower CT value.E. MATERIALS—CHEMISTRY AND MECHANICAL PROPERTIES

[0116] The strikeface is the only component intended to make direct contact with the golf ball and therefore absorbs a significant amount of energy to create ball speed and distance. Near alpha, alpha-beta, and beta alloys comprise mechanical properties suitable for use in the strikeface of a golf club head. Further, these alloys require shorter and simpler heat treatments to achieve the desired mechanical properties.

[0117] The strikeface, and therefore the front body and the return, can be formed from a front body material, classified as a near alpha, an alpha-beta, or a beta alloy. The classification of each material, and therefore the properties and reaction of each material, is dependent on the total wt % of each element within the given material. For example, the solvus temperature is determined by the amount of α and β stabilizers in the alloy. As the total wt % of the β stabilizers (such as vanadium and molybdenum) increases, the solvus temperature decreases. In contrast, as the total wt % of α stabilizers (such as aluminum) increases, the solvus temperature increases.

[0118] The material can have a total wt % of a stabilizer aluminum between 4 wt % and 9 wt %. The total wt % of aluminum can be between 4.0 wt % and 9.0 wt %, 4.1 wt % and 8.9 wt %, 4.2 wt % and 8.8 wt %, 4.3 wt % and 8.7 wt %, 4.4 wt % and 8.6 wt %, 4.5 wt % and 8.5 wt %, 4.6 wt % and 8.4 wt %, 4.7 wt % and 8.3 wt %, 4.8 wt % and 8.2 wt %, 4.9 wt % and 8.1 wt %, 5.0 wt % and 8.0 wt %, 5.1 wt % and 7.9 wt %, 5.2 wt % and 7.8 wt %, 5.3 wt % and 7.7 wt %, 5.4 wt % and 7.6 wt %. 5.5 wt % and 7.5 wt %, 5.6 wt % and 7.4 wt %, 5.7 wt % and 7.3 wt %, 5.8 wt % and 7.2 wt %, 5.9 wt % and 7.1 wt %, 6.0 wt % and 7.0 wt %, 6.1 wt % and 6.9 wt %, 6.2 wt % and 6.8 wt %, 6.3 wt % and 6.7 wt %, 6.4 wt % and 6.6 wt %. In some embodiments the total wt % of aluminum can be between 4.0 wt % and 4.2 wt %, 4.2 wt % and 4.4 wt %, 4.4 wt % and 4.6 wt %, 4.6 wt % and 4.8 wt %, 4.8 wt % and 5.0 wt %, 5.0 wt % and 5.2 wt %, 5.2 wt % and 5.4 wt %, 5.4 wt % and 5.6 wt %, 5.6 wt % and 5.8 wt %, 5.8 wt % and 6.0 wt %, 6.0 wt % and 6.2 wt %, 6.2 wt % and 6.4 wt %, 6.4 wt % and 6.6 wt %, 6.6 wt % and 6.8 wt %, 6.8 wt % and 7.0 wt %, 7.0 wt % and 7.2 wt %, 7.2 wt % and 7.4 wt %, 7.4 wt % and 7.6 wt %, 7.6 wt % and 7.8 wt %, 7.8 wt % and 8.0 wt %, 8.0 wt % and 8.2 wt %, 8.2 wt % and 8.4 wt %, 8.4 wt % and 8.6 wt %, 8.6 wt % and 8.8 wt %, or 8.8 wt % and 9.0 wt %. The presence of aluminum in Ti alloys can promote stability of its α phase at higher temperatures, allowing for higher temperature heat treatment to occur, improving strength and corrosion resistance by reducing stress.

[0119] The material can have a total wt % of β stabilizer vanadium between 1.5 wt % and 3.5 wt %. The wt % of β stabilizer vanadium can be between 1.5 wt % and 3.5 wt %, 1.6 wt % and 3.4 wt %, 1.7 wt % and 3.3 wt %, 1.8 wt % and 3.2 wt %, 1.9 wt % and 3.1 wt %, 2.0 wt % and 3.0 wt %, 2.1 wt % and 2.9 wt %, 2.2 wt % and 2.8 wt %, 2.3 wt % and 2.7 wt %, or 2.4 wt % and 2.6 wt %. In some embodiments, the total wt % of β stabilizer vanadium can be between 1.5 wt % and 1.7 wt %, 1.7 wt % and 1.9 wt %, 1.9 wt % and 2.1 wt %, 2.1 wt % and 2.3 wt %, 2.3 wt % and 2.5 wt %, 2.5 wt % and 2.7 wt %, 2.7 wt % and 2.9 wt %, 2.9 wt % and 3.1 wt %, 3.1 wt % and 3.3 wt %, or 3.3 wt % and 3.5 wt %.

[0120] The material can have a solvus temperature above 700° C. and below 1050° C. In certain embodiments, the solvus temperature can be between 700° C. and 725° C., 725° C. and 750° C., 750° C. and 775° C., 775° C. and 800° C., 800° C. and 825° C., 825° C. and 850° C., 850° C. and 875° C., 875° C. and 900° C., 900° C. and 925° C., 925° C. and 950° C., 950° C. and 975° C., 975° C. and 1000° C., 1000° C. and 1025° C., or 1025° C. and 1050° C. In certain embodiments, the solvus temperature can be below 800° C., below 825° C., below 850° C., below 875° C., below 900° C. and 925° C., below 950° C., below 975° C., below 1000° C., or below 1025° C. Similar to the solvus temperature the mechanical properties of the alloy can be determined by the chemical make-up of the alloy.1. 6-22-22

[0121] In some embodiments, the front body can be formed from titanium alloy 6-22-22 and its subtype derivatives depending upon its elements (including the wt % of impurities such as hydrogen and key action elements such as molybdenum and aluminum). 6-22-22 can have a solvus temperature between 900° C. and 1000° C. and a Moeq value of −0.80. The mechanical properties of titanium alloy 6-22-22 are modified through alloying and metal working to produce a strikeface with high strength and increased durability. The titanium alloy can be an α-β titanium (α-β Ti) alloy. Specifically, the α-β Ti alloys of the present invention each have a minimum yield strength of 170 ksi, a minimum tensile strength of 180 ksi, a minimum elongation of 5.0%, a Young's Modulus between 18 and 25 Mpsi, and a density between 4.410 g / cm3 and 4.710 g / cm3.

[0122] All numbers described below regarding composition describe weight as a total weight percent (wt %). In some embodiments, α-β Ti alloy 6-22-22 can have a total weight percent of α-stabilizer aluminum between 5.0 wt % to 7.0 wt %. 6-22-22 can have a total weight percent of tin between 1.0 wt % to 3.0 wt %, and a total weight percent of α-stabilizer zirconium between 1.0 wt % to 3.0 wt %. A total weight percent of 3-stabilizer molybdenum between 1.0 wt % to 3.0 wt %. A total weight percent of β-stabilizer chromium between 1.0 wt % to 3.0 wt %. A total weight percent of carbon less than or equal to 0.05 wt %. A total weight percent of nitrogen less than or equal to 0.03 wt %. A total weight percent of oxygen less than or equal to 0.14 wt %. A total weight percent of hydrogen less than or equal to 0.0125 wt %. The combination of α and β stabilizers, as discussed above, allows the α-β Ti alloys to be formed into durable lightweight strikeface. The composition of the front body material directly affects the way the material reacts during the formation process.2. Ti5325

[0123] In some embodiments, the front body can be formed from Ti5325 and its subtype derivatives depending upon its elements (including the wt % of impurities such as hydrogen and key action elements such as molybdenum and aluminum). Ti5325 can have a solvus temperature between 900° C. and 950° C. and a Moeq value of −2.99. The mechanical properties of Ti5325 are modified through alloying and metal working to produce a strikeface with high strength and increased durability.

[0124] In some embodiments, Ti5325 can have a total weight percentage of α-stabilizer aluminum between 3.5 wt % to 6.5 wt %. The presence of aluminum in Ti alloys can promote stability of its α phase at higher temperatures, improving strength and corrosion resistance by reducing stress. A total weight percent of β-stabilizer vanadium between 2.0 wt % to 4.0 wt %. A total weight percent of oxygen between 0.10 wt % and 0.30 wt %. A total weight percent of iron between 1.5 wt % and 3.5 wt %.

[0125] The grain structure of Ti5325 varies according to the forming temperature. For instance, at the adjacent solvus state the adjacent solvus average grain size may be between 3.87 μm and 4.97 μm. Additionally, grains structures formed at the sub-solvus state may produce a sub-solvus average grains size between 2.11 μm and 3.55 μm. In some embodiments, the sub-solvus average grain size may be between 2.55 μm to 3.10 μm. These grain sizes result in a percent grain size reduction from the adjacent solvus average grain size to the sub-solvus average grain size between 42% and 92%. In some embodiments, the percent grain size reduction from the solvus average grain size to the sub-solvus average grain size may be between 55% and 70%. The reduction in grain size increases the grain density within the material, wherein Ti5325 may comprise a grain density increase, relative to the adjacent solvus state, between 35% and 115%. Further, for materials in the intermediate sub-solvus state, the grain density increase, relative to the adjacent solvus state, may be between 35% and 50%. Materials in the deep sub-solvus state may have the grain density increase, relative to the adjacent solvus state, between 60% and 115%.3. HST 220

[0126] In some embodiments, the strikeface can be formed from α-β Ti alloy HST-220. α-β Ti alloy HST-220 has a solvus temperature of 980° C. and a Moeq value of −2.1657. HST-220 can have a total weight percent of α-stabilizer aluminum between 6.5 wt % to 8.5 wt %, a total weight percent of β-stabilizer molybdenum between 1.8 wt % to 3.2 wt %, a total weight percent of β-stabilizer iron less than or equal to 0.35 wt %, a total weight percent of α-stabilizer oxygen less than or equal to 0.2 wt %, a total weight percent of α-stabilizer carbon less than or equal to 0.15 wt %, a total weight percent of α-stabilizer nitrogen less than or equal to 0.1 wt %, a total weight percent of 3-stabilizer hydrogen less than or equal to 0.03 wt %, a total weight percent of β-stabilizer chromium between 1.0 wt % to 2.5 wt %, and a total weight percent of β-stabilizer silicon between 0.2 wt % to 0.3 wt %. α-β Ti alloy HST-220 can have a yield strength between 165 ksi to 187 ksi, an ultimate strength between 180 ksi to 220 ksi, an elongation at break between 5% to 14%, and a modulus of elasticity between 20 Mpsi to 35 Mpsi.4. T9S+

[0127] In some embodiments, the strikeface can be formed from titanium alloy T9S+ and its subtype derivatives depending upon its elements (including the wt % of impurities such as hydrogen and key action elements such as molybdenum and aluminum). T9S+ can have a solvus temperature between 1000° C. and 1050° C. and a Moeq value of −7.16. The mechanical properties of T9S+ are modified through alloying and metal working to produce a strikeface with high strength and increased durability. In some embodiments, the strikeface can be formed from near alpha titanium alloy T9S+. T9S+ can have a total weight percent of α-stabilizer aluminum between 7.8 wt % and 8.5 wt %, a total weight percent of β-stabilizer vanadium between 1.00 wt % and 1.50 wt %, a total weight percent of 0-stabilizer iron less than or equal to 0.40 wt %, a total weight percent of α-stabilizer oxygen less than or equal to 0.3 wt %, a total weight percent of α-stabilizer nitrogen less than or equal to 0.5 wt %, and a total weight percent of β-stabilizer silicon between 0.15 wt % to 0.25 wt %.F. METHOD OF MANUFACTURING

[0128] Forming the front body at a temperature between 150° C. and 325° C. below the solvus temperature preserves the mechanical properties of the material and provides a crystalline structure that is formed of small grains that are more equiaxed, providing isotropic properties. However, this lower than typical forming temperature requires other aspects of the manufacturing method to be altered. The tooling, as well as the temperature and the pressure at which the strikeface is formed, provides a strikeface with mechanical properties close to if not the same as the rolled material. The method of forming the front body 150° C. and 325° C. below solvus yields a strikeface with a crystalline structure having isotropic properties that allow strikeface thickness to be reduced without sacrificing strength and durability. Specifically, the tooling, design, added tonnage, and the forming temperature provides a strikeface with mechanical properties close to if not the same as the mechanical properties of the rolled material.

[0129] Near alpha alloys, alpha-beta alloys, and near beta alloys have a unique combination of strength and ductility. These alloys have a solvus temperature less than 1050° C. The method of manufacturing of the present invention involves forming the strikeface at a temperature between 150° C. and 325° C. less than the solvus temperature. This forming temperature lessens the impact the forming has on the mechanical properties. The strikeface is formed at a temperature between 150° C. and 155° C., 155° C. and 160° C., 160° C. and 165° C., 165° C. and 170° C., 170° C. and 175° C., 175° C. and 180° C., 180° C. and 185° C., 185° C. and 190° C., 190° C. and 195° C., 195° C. and 200° C., 200° C. and 205° C., 205° C. and 210° C., 210° C. and 215° C., 215° C. and 220° C., 220° C. and 225° C., 225° C. and 230° C., 230° C. and 235° C., 235° C. and 240° C., 240° C. and 245° C., 245° C. and 250° C., 250° C. and 255° C., 255° C. and 260° C., 260° C. and 265° C., 265° C. and 270° C., 270° C. and 275° C., 275° C. and 280° C., 280° C. and 285° C., 285° C. and 290° C., 290° C. and 295° C., 295° C. and 300° C., 300° C. and 305° C., 305° C. and 310° C., 310° C. and 315° C., 315° C. and 320° C., or 320° C. and 325° C., less than the solvus temperature. Forming significantly below (150° C. and 325° C.) the solvus temperature preserves the rolled material mechanical properties and crystallographic structure.

[0130] Forming the strikeface at the temperature range disclosed above helps retain the mechanical properties of the rolled material. However, forming the strikeface at this temperature range using traditional forming parameters (i.e., pressure and tooling geometry) yields a strikeface without the desired dimensions. The strikeface has a propensity to “springback” or partially return to an original contour and shape. This issue is overcome by altering the tooling design, increasing the pressure used to form the strikeface, or a combination thereof.

[0131] To account for springback, the strikeface may be deformed beyond the final shape. A strikeface for a wood-type club head, for example, will have curvatures known as bulge and roll. According to the present disclosure, the tooling used to form the strikeface can be configured to impart excessive deformation beyond the final shape, so that when the strikeface is released from the tooling it will revert to a shape that is closer to the desired final shape. Additionally, the tooling can be configured to yield a strikeface thicker than desired. Milling can then be applied to both the front and the back of the strikeface to arrive at the desired curvature.

[0132] Further, traditionally the press used to form a strikeface exerts pressure on the strikeface. The traditional process of forming a strikeface involves using a 300 ton press. Increasing that pressure can temper the springback effect on the strikeface. The method disclosed herein can include press tonnages in excess of 300 tons. In some embodiments a 700-800 ton press can be used to form a strikeface. In some embodiments, an 800-900 ton press can be used to form a strikeface. In one exemplary embodiment, an 800 ton press can be used to form a strikeface. The increased force can overcome the springback of the strikeface. The increase pressure can be used with the tooling design described above or with traditional tooling, depending on the degree of springback that particular material is prone to.

[0133] The material may oxidate during manufacturing. Oxidation can form during formation. Oxidation of titanium results in a strikeface with a brittle, oxygen-enriched outer surface that allows cracks to easily form and propagate. In some embodiments, the strikeface can be sprayed with an antioxidant coating. The use of an antioxidant coating, along with forming the strikeface at a lower temperature, can prevent the formation of an oxide layer. In other embodiments, the strikeface can be formed to have a thickness larger than desired, wherein a sacrificial top layer is removed by mechanical (i.e., cutting or grinding) or chemical (i.e., pickling) means.G. EXAMPLES1. Ti5325 Grain Orientation Example

[0134] This example illustrated the effects of forming temperature on the crystalline structure of Ti5325. Three samples of Ti5325 were formed at different temperatures. The solvus temperature of these samples was approximately 925° C. Sample 1 was formed at 830° C., an adjacent solvus forming temperature (95° C. below solvus). Sample 2 was formed at 730° C., an intermediate sub-solvus forming temperature (195° C. below solvus). Sample 3 was formed at 680° C., a deep sub-solvus forming temperature (245° C. below solvus). All three samples were analyzed in both the longitudinal and transverse direction with an EBSD microscope to compare the unique crystalline structures of each sample. Each sample has a grain orientation map that was evaluated over a sample area of 3,181 μm2.

[0135] Each sample was analyzed to determine the distribution of crystallographic orientations using color-coded EBSD figures, which depict the area fraction percentage of each orientation present. Area fraction percentage indicated how much of the scanned area is occupied by grains sharing a specific crystallographic orientation. Each color corresponded to one orientation family, and the percentage associated with that color represents the proportion of the total mapped area that exhibited that orientation. This helped quantify how dominant or scarce certain orientations are. Higher area fractions of particular orientations show preferred grain alignment, while more evenly distributed fractions show a more random or isotropic microstructure

[0136] Sample 1, seen in FIGS. 12 (longitudinal direction) and 15 (transverse direction), had a crystalline structure with a biased distribution of true basal, true prismatic, and true pyramidal orientations dominated by a single true orientation. The grain orientation map of sample 1, in the longitudinal direction (FIG. 12) comprised 65.15% true basal orientation (red), 4.50% true prismatic orientation (green), and 3.11% true pyramidal orientation (blue). The grain orientation maps of sample 1, in the transverse direction (FIG. 15), comprised 3.49% true basal orientation (red), 8.08% true prismatic orientation (green), and 79.34% true pyramidal orientation (blue). The grain orientation map of sample 1 illustrated that both directions were dominated by a single orientation (i.e. true basal for longitudinal and true pyramidal for transverse). The domination of the crystalline structure by a singular true orientation (depicted by the large clusters of single colored elongated grains) yielded directionality. This directionality created high strength in a first direction and low strength in a second direction, making the material unsuitable for a front body formed from a strikeface and a return.

[0137] Sample 2, seen in FIGS. 11 (longitudinal direction) and 14 (transverse direction), had a crystalline structure with a slightly more balanced distribution of true basal, true prismatic, and true pyramidal orientations with small groups of clumping. The grain orientation map of sample 2, in the longitudinal direction (FIG. 11) comprised 32.45% true basal orientation (red), 8.79% true prismatic orientation (green), and 4.87% true pyramidal orientation (blue). The grain orientation map of sample 2, in the transverse direction (FIG. 14), comprised 3.55% true basal orientation (red), 45.65% true prismatic orientation (green), and 24.60% true pyramidal orientation (blue). The grain orientation maps of sample 2 illustrated that true pyramidal, true basal, and true prismatic orientations were all present, but their relative fractions began to shift, and regions of clustering dissipated. The grains are closer to equiaxed, but some still remained at least partially elongated. In the transverse direction in particular the dominance of the true pyramidal orientation did normalize, only for the true prismatic orientation (green) to creep towards domination at 45.65%. This started to normalize the mechanical properties of in both directions.

[0138] Sample 3, seen in FIGS. 10 (longitudinal direction) and 13 (transverse direction), had a crystalline structure with a balanced distribution of true basal, true prismatic, and true pyramidal orientations. The grain orientation map of sample 3, in the longitudinal direction (FIG. 10) comprised 24.72% true basal orientation (red), 11.67% true prismatic orientation (green), and 16.39% true pyramidal orientation (blue). The grain orientation map of sample 3, in the transverse direction (FIG. 13), comprised 9.20% true basal orientation (red), 22.68% true prismatic orientation (green), and 29.61% true pyramidal orientation (blue). The grain orientation maps of sample 3 illustrated that true pyramidal, true basal, and true prismatic orientations were all relatively balanced. The grains were closer to equiaxed, with minimal clumping in both directions. The lower forming temperature of sample 3 yielded a balanced distribution of true basal, true prismatic, and true pyramidal orientations, wherein no single orientation of the true basal, true pyramidal, or true prismatic orientation exceeds 300 of the total area fraction. This orientation distribution indicated an isotropic material with no dominant crystallographic orientation. This provided isotropic mechanical properties in both the transverse and longitudinal direction.2. Ti5325 Example 1

[0139] In one example, two faceplates were formed from Ti5325 at each of the following temperatures: 550° C., 630° C., 650° C., 675° C., 730° C., 780° C., 830° C., and 900° C. The solvus temperature of these samples was approximately 925° C. Following the faceplate formation, each faceplate was analyzed to determine its mechanical properties. The mechanical properties of each sample are shown below in Table 1 and Table 2. Table 1 shows the mechanical properties of each sample cut in the longitudinal direction and Table 3 shows the mechanical properties of each sample cut in the transverse direction.TABLE 15325 Longitudinal Mechanical Properties by Forming TemperatureAreaunderTemper-YieldUltimateElon-curveatureStrengthStrengthgationModulusYield ×past(° C.)(ksi)(ksi)%(Mpsi)ElongationyieldBaseline15517014.016.02170227555015517015.016.02325243863015416815.516.02387249665015416816.015.82464257673015116515.515.62341244978014816316.815.52486261283014716215.515.1227923959001571788.115.512721357TABLE 25325 Transverse Mechanical Properties by Forming TemperatureAreaunderTemper-YieldUltimateElon-curveatureStrengthStrengthgationModulusYield ×past(° C.)(ksi)(ksi)%(Mpsi)ElongationyieldBaseline16817716.518.12772284655017017916.819.02848292763016817717.918.23013308765016817516.118.02697275773016517317.218.12838290978016417211.717.4191419638301611706.617.0106310939001671783.816.7633654As shown above in Tables 1 and 2, and illustrated in FIG. 17-22, the faceplate formed between 625° C. and 725° C. had the most desirable mechanical properties for application in golf. A downward trend in strength (ultimate and tensile) was experienced in the samples formed at 730° C. and above. Even though the sample formed at 900° C. does not follow this trend, the drastic dip in elongation indicates an extremely brittle material, making it unsuitable for application in golf. In the application of golf, the striking surface must be formed from a material well balanced in both strength and elongation. Therefore, the Yield×Elongation column, as shown above in Tables 1 and 2, and depicted in FIG. 21-22, was used to determine the ideal forming temperature for this example. As shown, as the forming temperature nears the solvus temperature (825° C. and above) the Yield x Elongation drastically decreases. The exact trend varies between the two directions. As such, the ideal forming temperature was determined based on the balance of the two (i.e., the forming temperature that yielded roughly the same values in both directions (a forming temperature between 650° C. and 735° C.). As such, it was determined that forming the faceplate at a temperature between 190° C. and 275° C. below the solvus temperature yielded the most desirable mechanical properties for the application of Ti5325 in a golf club head.3. Ti5325 Grain Size Example

[0141] Ti5325 illustrates the effect of forming temperature on grain size and its overall effects on the mechanical properties. In one example, three samples of Ti5325, which had a solvus temperature of approximately 925° C., were formed at different temperatures. Specifically, Sample 1 was formed at 830° C. Sample 2 was formed at 730° C. Sample 3 was formed at 680° C. Sample 1 was at the adjacent solvus state, and Samples 2 and 3 were at the sub-solvus state. All three samples were analyzed in both the longitudinal and transverse direction by an EBSD microscope to view their unique grain structures and measure the grain sizes of each sample. The grain structures were evaluated over a sample area of 3,181 μm2.

[0142] Sample 1, at the adjacent solvus state, produced an average grain size of 4.37 μm and a median grain size of 3.64 μm, in the longitudinal direction. The transverse direction had an average grain size of 4.47 μm, with a median grain size of 3.19 μm. Further, the sample area comprised 779 total grains in the longitudinal direction and 785 total grains in the transverse direction, which equated to a grain density of 0.24 grains / μm2 in the longitudinal direction and 0.25 grains / μm2 in the transverse direction.

[0143] Sample 2, at the sub-solvus state, produced an average grain size of 2.86 am and a median grain size of 2.51 μm, in the longitudinal direction. The transverse direction had an average grain size of 2.91 μm, with a median grain size of 2.48 μm. This represents percent grain size reductions for the average grain size of 65.4% in the longitudinal direction and 65.1% in the transverse direction, relative to Sample 1. Further, the sample area comprised 1,133 total grains in the longitudinal direction and 1,102 total grains in the transverse direction, which equated to a grain density of 0.36 grains / μm2 in the longitudinal direction and 0.35 grains / μm2 in the transverse direction.

[0144] Sample 3, at the sub-solvus state, produced an average grain size of 2.61 am and a median grain size of 2.21 μm, in the longitudinal direction. The transverse direction had an average grain size of 3.05 μm, with a median grain size of 2.65 am. This represents percent grain size reductions for the average grain size of 59.7% in the longitudinal direction and 68.2% in the transverse direction, relative to Sample 1. Further, the sample area comprised 1,289 total grains in the longitudinal direction and 1,635 total grains in the transverse direction, which equated to a grain density of 0.41 grains / μm2 in the longitudinal direction and 0.51 grains / μm2 in the transverse direction.

[0145] The reduction in grain size from Sample 1 to Samples 2 and 3 allowed for an increased grain density, which may correspond to increased durability. Specifically, Samples 2 and 3 saw a grain density increase, compared to sample 1, of 45% and 65%, respectively in the longitudinal direction, a grain density increase of 40% and 108%, respectively, in the transverse direction. This decrease of grain size and corresponding increase in grain density can be attributed to the lower forming temperatures of Samples 2 and 3, which resulted in samples being in the sub-solvus state, while Sample 1 was in the adjacent solvus state.4. 6-22-22 Example

[0146] Similar to the Ti5325 Example discussed above, 6-22-22 has shown to have desirable characteristics for golf faceplates when compared to traditionally used faceplate materials, such as traditionally formed T9S+. In one example, two faceplates were formed from 6-22-22 at each of the following temperatures: 550° C., 600° C., 625° C., 650° C., 675° C., 700° C., 750° C., 800° C. The solvus temperature of these samples was approximately 960° C. Following the faceplate formation, each faceplate was analyzed to determine its mechanical properties. The mechanical properties of each sample are shown below in Table 3 and Table 4. Table 3 shows the mechanical properties of each sample cut in the longitudinal direction and Table 5 shows the mechanical properties of each sample cut in the transverse direction.TABLE 36-22-22 Longitudinal MechanicalProperties by Forming TemperatureAreaunderTemper-YieldUltimateElon-curveatureStrengthStrengthgationModulusYield ×past(° C.)(ksi)(ksi)%(Mpsi)ElongationyieldBaseline160.5165.52.916.6457465550158162.54.316.5672681600156.5163.55.516.0861880625157164.54.816.27467646501581687.316.3114611826751541594.421.46786897001471588.017.911761220750137.51498.315.3113411828001381465.315.4725746TABLE 46-22-22 Transverse Direction MechanicalProperties by Forming TemperatureAreaunderTemper-YieldUltimateElon-curveatureStrengthStrengthgationModulusYield ×past(° C.)(ksi)(ksi)%(Mpsi)ElongationyieldBaseline16617912.819.02110219355016818013.819.3231023936001651759.319.31526157062516617914.019.32324241565016517813.819.22262235567515117616.519.12483269470015917217.319.42734285175015016216.519.32475257080014815815.318.122572329As shown above in Tables 3 and 4 and illustrated in FIG. 23-28, the faceplate formed between 625° C. and 750° C. had the most desirable mechanical properties for 6-22-22 in the application in golf. A steep drop (over 50 ksi / 50) in yield strength, in both the transverse and longitudinal directions, was experienced in the samples formed at 650° C. and above. However, in the application of golf, the striking surface must be formed from a material well-balanced in both strength and elongation. Therefore, the Yield x Elongation column, as shown above in Tables 3 and 4, and depicted in FIG. 27-28, was also taken into consideration for this example. The exact trend varies between the two directions. As such, the ideal forming temperature was determined based on the balance of the two (i.e., the forming temperature that yielded roughly the same values in both directions). In this example the use of a forming temperature over 700° C. was found to be unsatisfactory as it was the start of a downward trend in the transverse direction. As such, it was determined that forming the faceplate at a temperature between 210° C. and 335° C. below the solvus temperature yielded the most desirable mechanical properties for the application of Ti 6-22-22 in a golf club head.5. Ti52AFS Example

[0148] In another example, two faceplates were formed from Ti52AFS at each of the following temperatures: 550° C., 650° C., 730° C., 780° C., 830° C., and 900° C. The solvus temperature of these samples was approximately 960° C. Following the faceplate formation, each faceplate was analyzed to determine its mechanical properties. The mechanical properties of each sample are shown below in Table 5 and Table 6. Table 5 shows the mechanical properties of each sample cut in the longitudinal direction and Table 6 shows the mechanical properties of each sample cut in the transverse direction.TABLE 5Ti52AFS First Direction MechanicalProperties by Forming TemperatureAreaunderTemper-YieldUltimateElon-curveatureStrengthStrengthgationModulusYield ×past(° C.)(ksi)(ksi)%(Mpsi)ElongationyieldBaseline12914815.516.22000214755013815314.716.82029213965013715116.320.52233234773013515014.016.71890199578013214715.216.52006212083012814416.316.32086221790012914415.516.420002116TABLE 6Ti52AFS Second Direction MechanicalProperties by Forming TemperatureAreaunderTemper-YieldUltimateElon-curveatureStrengthStrengthgationModulusYield ×past(° C.)(ksi)(ksi)%(Mpsi)ElongationyieldBaseline16116914.820.22383244255016317616.320.62657276365016117216.320.52624271473015917114.020.02226231078015816914.520.42291237183015316615.020.42295239390014816214.820.121902294As shown above in Tables 5 and 6 and illustrated in FIG. 29-32, a strikeface made of Ti52AFS and formed between 650° C. and 700° C. had the most desirable mechanical properties for application in golf. The yield strength decreased as the forming temperature increased. However, in the application of golf, the striking surface must be formed from a material well-balanced in both strength and elongation. Therefore, the Yield x Elongation column, as shown above in Tables 5 and 6, was also taken into consideration for this example. The Yield x Elongation follows a similar trend to the yield strength and trends downward as the forming temperature nears solvus. As such, it was determined that forming the faceplate at a temperature between 260° C. and 315° C. below the solvus temperature yielded the most desirable mechanical properties for the application of Ti52AFS in a golf club head.

[0150] Additionally, the grain structure of Ti52AFS was analyzed at two of the forming temperatures, 830° C. and 730° C. At 830° C. (adjacent solvus state) the adjacent solvus average grain size was between 5.0 μm and 5.5 μm. Grain structures formed 730° C. (sub-solvus state) produced a sub-solvus average grain size between 3.9 μm and 4.9 μm. These grain sizes result in a percent grain size reduction between 71% and 98% for materials in the sub-solvus state. Reducing the grain size increases the grain density within a material, wherein Ti52AFS may comprise a grain density increase, relative the adjacent solvus state, between 75% and 120% for materials in the sub-solvus state. The reduced grain size indicated the increased yield strength, as more boundaries restricted dislocation movement and delayed crack initiation.6. 5325 Durability Example

[0151] A test was conducted to compare the effect of forming temperature on the strikeface over the course of 2,000 hits or golf ball strikes. However, the data presented is limited to the first 250 hits or ball strikes wherein the majority of the changes take place. The data between 250 and 2,000 hits or ball strikes plateaus and follows a similar progression as the data displayed for 100 to 250 hits. Each club was hit till failure and the number of hits to failure was recorded.

[0152] The golf club heads of this example had a front body formed from Ti 5235 at varying temperatures. A first control club head (hereafter referred to “Control 1”) having a front body formed from 5325 was formed at a temperature of 830° C. (95° C. below the solvus temperature). A second control club head (hereafter referred to “Test 1”) had a front body formed at a temperature of 730° C. (195° C. below the solvus temperature). A third control club head (hereafter referred to “Test 2”) had a front body formed at a temperature of 680° C. (245° C. below the solvus temperature). All three control club heads were oriented in the same direction. The results can be seen below in Table 7.TABLE 7Effect Forming Temperature has on Bulge and Roll RadiusDeformation at 250 Hits of Ti 5325BulgeRollFormingBulgeRadiusRollRadiusTemperatureRadiusChangeRadiusChangeHits to(° C.)(in)(in)(in)(in)FailureControl 1830° C.0.0014-0.5-0.0014-0.8-21310.00191.30.00200.8Test 1730° C.0.0029-2.2-0.0029-1.1-26980.00372.40.00371.9Test 2680° C.0.0026-1.4-0.0026-0.69-27810.0291.70.00310.69

[0153] As shown in Table 7, the deformation in roll radius (Roll Radius Change) after 250 hits improved by 13.75% from Control 1 to Test 2. While the deformation in bulge radius (Bulge Radius Change) did decline, the drastic 30.50% improvement in hits till failure of Test 2 over Control 1 displayed the improvement in strength and elasticity created by forming the front body of the golf club head at a temperature (approx.) 250° C. degrees below solvus. This drastic improvement in hits till failure displayed the improvement in strength and elongation as the forming temperature decreased.CLAUSES

[0154] Clause 1. A golf club head comprising: a crown, a sole opposite the crown, a toe end, a heel end opposite the toe end, and a rear end; a rear body; a front body formed of a front body material having a solvus temperature between 700° C. and 1050° C., comprising: a strikeface having a striking surface and a back surface opposite the striking surface; and a return extending rearward from the strikeface to form at least a portion of at least one of the sole, the crown, the heel end, or the toe end; and wherein the front body is formed at a sub-solvus state at a temperature at least 200° C. below the solvus temperature of a front body material such that the front body material has a crystallographic orientation with no volume fraction than 30% for any one of a true pyramidal, true basal, or true prismatic grain orientation.

[0155] Clause 2. The golf club head of clause 1, wherein the front body material comprises: an adjacent solvus average grain size at an adjacent solvus state; a sub-solvus average grain size at the sub-solvus state; and a percent grain size reduction from the adjacent solvus average grain size to the sub-solvus average grain size between 55% to 70%.

[0156] Clause 3. The golf club head of clause 1, wherein the front body material comprises a longitudinal sample area comprising; a true basal orientation percentage above 60% of the total volume fraction at an adjacent solvus state; and a true basal orientation percentage below 30% of the total volume fraction at the sub-solvus state.

[0157] Clause 4. The golf club head of clause 1, wherein the front body can be oriented such that a longitudinal direction extends in a crown-to-sole direction.

[0158] Clause 5. The golf club head of clause 1, wherein the front body material comprises a transverse sample area comprising; a true pyramidal orientation percentage above 60% of the total volume fraction at an adjacent solvus state; and a true pyramidal orientation percentage below 30% of the total volume fraction at the sub-solvus state.

[0159] Clause 6. The golf club head of clause 1, wherein the front body can be oriented such that a transverse direction extends in a crown-to-sole direction.

[0160] Clause 7. The golf club head of clause 1, wherein the strikeface comprises a minimum thickness, measured in a direction perpendicular to a loft plane, between 0.075-0.118 inches.

[0161] Clause 8. The golf club head of clause 1, wherein the return comprises at least a portion of the sole having an impact response modulator monolithically formed with the front body.

[0162] Clause 9. The golf club head of clause 8, wherein the impact response modulator is positioned proximate to the strikeface.

[0163] Clause 10. The golf club head of clause 8, wherein the impact response modulator comprises a casing that forms one or more walls defining an aperture providing an opening though the sole, wherein the opening communicates between an interior cavity of the golf club head and an environment surrounding the golf club head.

[0164] Clause 11. The golf club head of clause 10, wherein the impact response modulator further comprises an insert positioned within the aperture and formed of a flexible, polymeric material.

[0165] Clause 12. The golf club head of clause 1, wherein the front body material is formed from 5325.

[0166] Clause 13. The golf club head of clause 12, wherein the sub-solvus average grain size at the sub-solvus state is between 2.55 micrometers to 3.10 micrometers.

[0167] Clause 14. The golf club head of clause 1, wherein the front body material is formed from 52AFS.

[0168] Clause 15. The golf club head of clause 14, wherein the sub-solvus average grain size at the sub-solvus state is between 4.00 micrometers to 4.75 micrometers.

[0169] Clause 16. A golf club head comprising: a crown, a sole opposite the crown, a toe end, a heel end opposite the toe end, and a rear end; a rear body; a front body formed of a front body material having a solvus temperature between 700° C. and 1050° C., comprising: a strikeface having a striking surface and a back surface opposite the striking surface; a return extending rearward from the strikeface to form at least portions of the crown and the sole; wherein the front body material is formed at a sub-solvus state at a temperature at least 200° C. below the solvus temperature of a front body material comprising: an adjacent solvus average grain size at an adjacent solvus state; a sub-solvus average grain size at the sub-solvus state; and a percent grain size reduction from the adjacent solvus average grain size to the sub-solvus average grain size between 55% to 70%; the front body material at the sub-solvus state has no volume fraction greater than 30% for any one of a true pyramidal, true basal, or true prismatic grain orientation.

[0170] Clause 17. The golf club head of clause 16, wherein the strikeface comprises a minimum thickness, measured in a direction perpendicular to a loft plane, between 0.075-0.118 inches.

[0171] Clause 18. The golf club head of clause 16, wherein the return comprises an impact response modulator monolithically formed with the front body.

[0172] Clause 19. The golf club head of clause 18, wherein the impact response modulator comprises a casing that forms one or more walls defining an aperture providing an opening though the sole, communicating between an interior cavity of the golf club head and an environment surrounding the golf club head.

[0173] Clause 20. The golf club of clause 1, wherein an orientation imaging map obtained from an EBSD scan of the front body material has no area fraction greater than 30% for any one of a true pyramidal, true basal, or true prismatic grain orientation.

[0174] Clause 21. A golf club head comprising: a crown, a sole opposite the crown, a toe end, a heel end opposite the toe end, and a rear end; a rear body; a front body formed of a front body material having a solvus temperature between 700° C. and 1050° C., comprising: a strikeface having a striking surface and a back surface opposite the striking surface; and a return extending rearward from the strikeface to form at least a portion of at least one of the sole, the crown, the heel end, or the toe end; and wherein the front body is formed at a sub-solvus state at a temperature at least 200° C. below the solvus temperature of a front body material such that the front body material has a crystallographic orientation wherein the front body material comprises a longitudinal sample area comprising; a true basal orientation percentage above 60% of the total volume fraction at an adjacent solvus state; and a true basal orientation percentage below 30% of the total volume fraction at the sub-solvus state.

[0175] Clause 22. The golf club head of clause 21, wherein the face body can be oriented such that the longitudinal direction extends in a crown-to-sole direction.

[0176] Clause 23. The golf club head of clause 21, wherein the strikeface comprises a minimum thickness, measured in a direction perpendicular to a loft plane, between 0.075-0.118 inches.

[0177] Clause 24. The golf club head of clause 21, wherein the return comprises an impact response modulator monolithically formed with the front body.

[0178] Clause 25. The golf club head of clause 24, wherein the impact response modulator is positioned proximately to the strikeface.

[0179] Clause 26. The golf club head of clause 24, wherein the impact response modulator comprises a casing that forms one or more walls defining an aperture providing an opening though the sole, communicating between an interior cavity of the golf club head and an environment surrounding the golf club head.

[0180] Clause 27. The golf club head of clause 26, wherein the impact response modulator further comprises an insert positioned within the aperture and formed of a flexible, polymeric material.

[0181] Clause 28. A golf club head comprising: a crown, a sole opposite the crown, a toe end, a heel end opposite the toe end, and a rear end; a rear body; a front body formed of a front body material having a solvus temperature between 700° C. and 1050° C., comprising: a strikeface having a striking surface and a back surface opposite the striking surface; and a return extending rearward from the strikeface to form at least a portion of at least one of the sole, the crown, the heel end, or the toe end; and wherein the front body is formed at a sub-solvus state at a temperature at least 200° C. below the solvus temperature of a front body material such that the front body material has a crystallographic orientation wherein the front body material comprises a transverse sample area comprising; a true pyramidal orientation percentage above 60% of the total volume fraction at an adjacent solvus state; and a true pyramidal orientation percentage below 30% of the total volume fraction at the sub-solvus state.

[0182] Clause 29. A golf club head comprising: a crown, a sole opposite the crown, a toe end, a heel end opposite the toe end, and a rear end; a rear body; a front body formed of a front body material having a solvus temperature between 700° C. and 1050° C., comprising: a strikeface having a striking surface and a back surface opposite the striking surface; and a return extending rearward from the strikeface to form at least a portion of at least one of the sole, the crown, the heel end, or the toe end; and wherein the front body is formed at a sub-solvus state at a temperature at least 200° C. below the solvus temperature of a front body material such that the front body material has a crystallographic orientation wherein the front body material comprises a longitudinal sample area comprising: a true basal orientation percentage between 50% and 60% of the total volume fraction at an adjacent solvus state; and a true basal orientation percentage between 20% and 30% of the total volume fraction at the sub-solvus state.

[0183] Clause 30. A golf club head comprising: a crown, a sole opposite the crown, a toe end, a heel end opposite the toe end, and a rear end; a rear body; a front body formed of a front body material having a solvus temperature between 700° C. and 1050° C., comprising: a strikeface having a striking surface and a back surface opposite the striking surface; and a return extending rearward from the strikeface to form at least a portion of at least one of the sole, the crown, the heel end, or the toe end; and wherein the front body is formed at a sub-solvus state at a temperature at least 200° C. below the solvus temperature of a front body material such that the front body material has a crystallographic orientation wherein the front body material comprises a transverse sample area comprising; a true pyramidal orientation percentage between 50% and 60% of the total volume fraction at an adjacent solvus state; and a true pyramidal orientation percentage between 20% and 30% of the total volume fraction at the sub-solvus state.

[0184] Clause 31. A golf club head comprising: a crown, a sole opposite the crown, a toe end, a heel end opposite the toe end, and a rear end; a rear body; a front body formed of a front body material having a solvus temperature between 700° C. and 1050° C., comprising: a strikeface having a striking surface and a back surface opposite the striking surface; and a return extending rearward from the strikeface to form at least a portion of at least one of the sole, the crown, the heel end, or the toe end; and wherein the front body is formed at a sub-solvus state at a temperature at least 200° C. below the solvus temperature of a front body material such that the front body material has a crystallographic orientation wherein the front body material comprises a longitudinal sample area comprising; wherein the front body material comprises: An adjacent solvus average grain size at an adjacent solvus state; a sub-solvus average grain size at the sub-solvus state; and a percent grain size reduction from the adjacent solvus average grain size to the sub-solvus average grain size between 55% to 70%; a true basal orientation percentage between 50% and 60% of the total volume fraction at an adjacent solvus state; and a true basal orientation percentage between 20% and 30% of the total volume fraction at the sub-solvus state.

[0185] Clause 32. A golf club head comprising: a crown, a sole opposite the crown, a toe end, a heel end opposite the toe end, and a rear end; a rear body; a front body formed of a front body material having a solvus temperature between 700° C. and 1050° C., comprising: a strikeface having a striking surface and a back surface opposite the striking surface; and a return extending rearward from the strikeface to form at least a portion of at least one of the sole, the crown, the heel end, or the toe end; and wherein the front body is formed at a sub-solvus state at a temperature at least 200° C. below the solvus temperature of a front body material such that the front body material has a crystallographic orientation wherein the front body material comprises a transverse sample area comprising; wherein the front body material comprises: An adjacent solvus average grain size at an adjacent solvus state; a sub-solvus average grain size at the sub-solvus state; and a percent grain size reduction from the adjacent solvus average grain size to the sub-solvus average grain size between 55% to 70%; a true pyramidal orientation percentage between 50% and 60% of the total volume fraction at an adjacent solvus state; and a true pyramidal orientation percentage between 20% and 30% of the total volume fraction at the sub-solvus state.

[0186] Replacement of one or more claimed elements constitutes reconstruction and not repair. Additionally, benefits, other advantages, and solutions to problems have been described with regard to specific embodiments. The benefits, advantages, solutions to problems, and any element or elements that may cause any benefit, advantage, or solution to occur or become more pronounced, however, are not to be construed as critical, required, or essential features or elements of any or all of the claims, unless such benefits, advantages, solutions, or elements are stated in such claim.

[0187] Moreover, embodiments and limitations disclosed herein are not dedicated to the public under the doctrine of dedication if the embodiments and / or limitations: (1) are not expressly claimed in the claims; and (2) are or are potentially equivalents of express elements and / or limitations in the claims under the doctrine of equivalents.

Examples

Embodiment Construction

[0086]The golf club heads described herein have a high strength titanium alloy strikeface with a more isotropic crystal structure and more isotropic mechanical properties than conventional strikefaces. The golf club heads have a front body, comprising a strikeface and a return formed of a near alpha alloy, an alpha-beta alloy, or a near beta alloy having a solvus temperature between 700° C. and 1050° C. Forming the front body at a temperature between 150° C. and 325° C. below the solvus temperature, using an increased tonnage to shape the front body, yields a crystalline structure with smaller grain size and reduced directionality compared to materials formed at solvus or adjacent solvus temperatures. Forming at such sub-solvus temperatures require fabrication techniques and equipment capable of applying a magnitude of tonnage not used before to form golf clubs. As the forming temperature is lowered further below the solvus of the metal, the amount of tonnage must be increased. Incr...

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This claims the benefit of U.S. Provisional Patent Application No. 63 / 825,406 filed on Jun. 17, 2025, and U.S. Provisional Patent Application No. 63 / 755,725 filed on Feb. 7, 2025.TECHNICAL FIELD

[0002] The present disclosure relates generally to golf clubs, and more particular to near alpha titanium alloys, α-β titanium alloys, and near beta titanium alloys for application in golf.BACKGROUND

[0003] The strikeface of a golf club head must be sufficiently durable to withstand repetitive contact with the golf ball. The reaction forces produced at impact generate transferable energy. At the start of impact, the strikeface contacts the golf ball and starts to deflect. Once the strikeface reaches maximum deflection, it inflects and starts to return to the original, undeflected state. As the strikeface returns to an undeflected state, it converts the potential energy stored in the strikeface into kinetic energy that is transferred to the golf ball. The resulting ball speed greatly depends on the efficiency of this energy transfer. Therefore, the strikeface must be sufficiently elastic to deform and regain its original structure at impact to generate ball speed while being sufficiently durable to withstand repeated impacts. Metal alloys, such as titanium alloys, are relatively strong and lightweight, and therefore can be formed relatively thin to generate ball speed while still being sufficiently durable to withstand repeated impacts.

[0004] Certain titanium alloys, such as near alpha alloys, alpha-beta alloys, and near beta alloys, have a unique combination of strength and ductility. The raw material of these titanium alloys have chemical compositions with advantageous mechanical properties for use as strikefaces for golf club heads. However, traditional fabrication processes used to convert the raw material into a final shape deteriorate those mechanical properties. Further, as titanium is naturally anisotropic, titanium structures generally possess directionality, which can be exacerbated by the forming process. Pronounced directionality will strengthen the titanium in one direction while weakening the titanium in another direction, which can reduce suitability of such materials for certain golf club head applications.BRIEF DESCRIPTION OF DRAWINGS

[0005] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee. To facilitate further description of the embodiments, the following drawings are provided in which:

[0006] FIG. 1 illustrates a rear, toe-side perspective view of a golf club head according to the present disclosure.

[0007] FIG. 2 illustrates side a toe-side elevation view of a golf club head according to the present invention, in cross-section.

[0008] FIG. 3 illustrates bottom, plan view of a golf club head according to the present invention.

[0009] FIG. 4 illustrates a detailed, toe-side elevation view of the golf club head according to the present invention, in cross-section.

[0010] FIG. 5 illustrates side a toe-side elevation view of a golf club head according to the present invention, in cross-section.

[0011] FIG. 6 illustrates a toe-side elevation view of a golf club head according to the present invention.

[0012] FIG. 7 illustrates a top, front-side perspective view of a golf club head according to the present invention.

[0013] FIG. 8 illustrates a bottom, front-side perspective view of a golf club head according to the present invention.

[0014] FIG. 9 illustrates a schematic diagram of a metal sheet formed according to the present invention from which are cut a transverse and longitudinal tensile bar.

[0015] FIG. 10 illustrates an EBSD grain orientation map, in the longitudinal direction, for a material according to the present invention in the sub-solvus state.

[0016] FIG. 11 illustrates an EBSD grain orientation map, in the longitudinal direction, for a material in the sub-solvus state according to the present invention.

[0017] FIG. 12 illustrates an EBSD grain orientation map, in the longitudinal direction, for a material in the adjacent solvus state.

[0018] FIG. 13 illustrates an EBSD grain orientation map, in the transverse direction, for a material in the sub-solvus state according to the present invention.

[0019] FIG. 14 illustrates an EBSD grain orientation map, in the transverse direction, for a material in the sub-solvus state according to the present invention.

[0020] FIG. 15 illustrates an EBSD grain orientation map, in the transverse direction, for a material in the adjacent solvus state.

[0021] FIG. 16A illustrates an EBSD grain orientation map, in the transverse direction, for a material in the adjacent solvus state.

[0022] FIG. 16B illustrates an EBSD grain orientation map, in the transverse direction, for a material in the intermediate sub-solvus state.

[0023] FIG. 16C illustrates an EBSD grain orientation map, in the transverse direction, for a material in the deep sub-solvus state.

[0024] FIG. 17 illustrates a graphical depiction of forming temperature vs. yield strength, in the longitudinal direction, for Ti5325.

[0025] FIG. 18 illustrates a graphical depiction of forming temperature vs. elongation, in the longitudinal direction, for Ti5325.

[0026] FIG. 19 illustrates a graphical depiction of forming temperature vs. yield strength, in the transverse direction, for Ti5325.

[0027] FIG. 20 illustrates a graphical depiction of forming temperature vs. elongation, in the transverse direction, for Ti5325.

[0028] FIG. 21 illustrates a graphical depiction of forming temperature vs. yield×elongation, in the longitudinal direction, for Ti5325.

[0029] FIG. 22 illustrates a graphical depiction of forming temperature vs. yield×elongation, in the transverse direction, for Ti5325.

[0030] FIG. 23 illustrates a graphical depiction of forming temperature vs. yield strength, in the longitudinal direction, for 6-22-22.

[0031] FIG. 24 illustrates a graphical depiction of forming temperature vs. yield strength, in the transverse direction, for 6-22-22.

[0032] FIG. 25 illustrates a graphical depiction of forming temperature vs. elongation, in the longitudinal direction, for 6-22-22.

[0033] FIG. 26 illustrates a graphical depiction of forming temperature vs. elongation, in the transverse direction, for 6-22-22.

[0034] FIG. 27 illustrates a graphical depiction of forming temperature vs. yield×elongation, in the longitudinal direction, for 6-22-22.

[0035] FIG. 28 illustrates a graphical depiction of forming temperature vs. yield×elongation, in the transverse direction, for 6-22-22.

[0036] FIG. 29 illustrates a graphical depiction of forming temperature vs. yield strength, in the longitudinal direction, for Ti52AFS.

[0037] FIG. 30 illustrates a graphical depiction of forming temperature vs. elongation, in the longitudinal direction, for Ti52AFS.

[0038] FIG. 31 illustrates a graphical depiction of forming temperature vs. yield strength, in the transverse direction, for Ti52AFS.

[0039] FIG. 32 illustrates a graphical depiction of forming temperature vs. elongation, in the transverse direction, for Ti52AFS.

[0040] For simplicity and clarity of illustration, the drawing figures illustrate the general manner of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the invention. Additionally, elements in the drawing figures are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the present invention. The same reference numerals in different figures denote the same elements.Definitions

[0041] The terms “first,”“second,”“third,”“fourth,” and the like in the description and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms “include,” and “have,” and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, device, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such process, method, system, article, device, or apparatus.

[0042] The terms “left,”“right,”“front,”“back,”“top,”“bottom,”“over,”“under,” and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein.

[0043] The terms “couple,”“coupled,”“couples,”“coupling,” and the like should be broadly understood and refer to directly or indirectly connecting two or more elements or signals, electrically, mechanically and / or otherwise.

[0044] The term “composition,” as described herein, is defined as the kinds and relative count of elements in a material. For alloyed materials, the composition describes the weight percentage of each alloying element within the material. All weight percent (wt %) numbers described below are a total weight percent.

[0045] The term “α stabilizers,” as described herein, is defined as a type of element in a titanium alloy, such as aluminum, oxygen, nitrogen, and carbon. These elements promote the alloy to exist in the α phase at typical ambient temperatures.

[0046] The term “β stabilizers,” as described herein, is defined as a type of element in 25a titanium alloy, such as molybdenum, vanadium, iron, and silicon. These elements promote the alloy to exist in the β phase at typical ambient temperatures.

[0047] The term “near alpha alloy,” as described herein, is defined as an alloy comprising a low amount of β stabilizing elements. Typically, between 1-3 wt % of one or more β stabilizing element.

[0048] The term “alpha-beta alloy,” as described herein, is defined as an alloy comprising approximately 10% beta phase at room temperature.

[0049] The term “near beta alloy,” as described herein, is defined as an alloy comprising approximately 10% to 15% beta phase at room temperature.

[0050] The term “beta alloy,” as described herein, is defined as an alloy containing enough beta-stabilizers to retain its beta phase when quenched to room temperature.

[0051] The term “crystal structure,” as described herein, is defined as the material on the atomic scale and refers to the manner in which atoms or ions are spatially arranged. Crystal structure is defined in terms of unit cell geometry.

[0052] The term “microstructure,” as described herein, is defined as the structural features of a material that can be seen using a microscope. Microstructure includes grain boundaries, grain size, grain shape, dislocations, precipitates, inclusions, pores, voids, and phase structures. These features can seldom be seen with the naked eye.

[0053] The term “crystallographic,” as described herein, is defined as a collection of many repeating crystalline structures all oriented in different directions. Features of the grain structure, such as grain size, grain shape, and grain orientation, can affect the mechanical properties of the material. The size of the grain can affect the strength of the material; wherein smaller gains typically result in stronger materials.

[0054] The term “grain orientation,” as described herein, is defined as having the specific crystallographic alignment of individual crystal lattices (grains) within a polycrystalline material.

[0055] The term “grain boundaries,” as described herein, is defined as the planar defects that occur where two grains meet. Grain boundaries disrupt the motion of dislocations throughout the material, caused by a force applied to the material. The more grain boundaries that are impacted by an external force the less deformation the material will undergo.

[0056] The term “crystallographic texture,” as described herein, is defined as the non-random, directional arrangement of crystals within a polycrystalline material.

[0057] The term “equiaxed,” as described herein, is defined as a grain structure wherein the dimensions in all directions are roughly equal. Essentially, equiaxed grains are approximately equidimensional, having similar lengths, widths, and heights, giving them a roughly spherical or polygonal shape.

[0058] The term “anisotropic,” as described herein, is defined as the mechanical properties of the material having different values when measured in different directions.

[0059] The term “isotropic,” as described herein, is defined as the mechanical properties of the material being approximately the same in all directions.

[0060] The term “stress-strain curve,” as described herein, is defined as to a graphical depiction of the amount of deflection under load for a particular material. Engineering stress is represented on the X-axis of the graph and engineering strain is represented on the Y-axis of the graph.

[0061] The term “engineering stress (S),” as described herein, is defined as the value calculated by dividing the load (P) at any given time by the original cross-sectional area (Ao) of the sample.

[0062] The term “engineering strain (e),” as described herein, is defined as the ratio between the elongation of the gage length (l) of the specimen and the original length (Io).

[0063] The term “rolled material,” as described herein, is defined as the base sheet of material from which front body is cut from.

[0064] The term “tensile strength,” as described herein, is defined as the maximum strength under a tensile or pulling load that a material can absorb without failure. Here, failure is experienced when fracture, snapping, or breakage occurs.

[0065] The term “brittleness,” as described herein, is defined as the failure by sudden fracture, without plastic deformation. Brittleness is further defined as the absence of ductility.

[0066] The “modulus of elasticity” or “Young's Modulus,” as described herein, is defined as the ratio of stress to strain and is the slope (E) of the stress-strain curve in the elastic region. The modulus is used to describe a material's stiffness.

[0067] The term “yield strength” or “proportional limit,” as described herein, is defined as the point on the stress strain curve wherein the material is loaded in tension to the point of permanent, or plastic deformation, such that the deformation remains when the load has been removed.

[0068] The term “spring back” as described herein, is defined as the change is shape (partial reversion back to its original shape) that occurs when a sheet of metal is released from the forming tool after being pressed.

[0069] The term “forming temperature,” as described herein, is defined as the strikeface heating temperature enabling strikeface manipulation to form the VFT and bulge and roll.

[0070] The term “Electron Backscatter Diffraction (EBSD) analysis,” as described herein, is defined as measuring the crystallographic orientation of each grain by determining the misorientation angles between adjacent grains. The misorientation angles represent the angular difference between the crystallographic orientation of adjacent grains.

[0071] The term “Molybdenum Equivalency Equation,” as described herein, is defined as an equation that quantifies the beta-stabilizing effect of alloying elements (like Mo, V, Nb, Cr, Co) in titanium, helping predict properties like the beta solvus temperature and phase stability. The Molybdenum Equivalency Equation yields a Moeq value.

[0072] The term “strikeface,” as described herein, is defined as a club head front surface that is configured to strike a golf ball. The term strikeface can be used interchangeably with the term “face.”

[0073] The term “strikeface perimeter,” as described herein, is defined as an edge of the strikeface. The strikeface perimeter can be located along an outer edge of the strikeface where the curvature deviates from a bulge and / or roll of the strikeface. The strikeface comprises a bulge curvature and a roll curvature. The bulge curvature is the curvature of the strikeface in the heel-to-toe direction. The roll curvature is the curvature of the strikeface in a crown-to-sole direction. The bulge curvature and the roll curvature each respectively comprise a bulge radius and a roll radius defining the radii of curvature associated with each of the bulge curvature and the roll curvature. The bulge curvature and / or the roll curvature can comprise one or more radii.

[0074] An “XYZ” coordinate system of the golf club head, as described herein, is based upon the geometric center of the strikeface. The golf club head dimensions described herein can be measured based on a coordinate system as defined below. The geometric center of the strikeface defines a coordinate system having an origin located at the geometric center of the strikeface. The coordinate system defines an X axis, a Y axis, and a Z axis. The X axis extends through the geometric center of the strikeface in a direction from the heel to the toe of the fairway-type club head. The Y axis extends through the geometric center of the strikeface in a direction from the crown to the sole of golf club head. The Y axis is perpendicular to the X axis. The Z axis extends through the geometric center of the strikeface in a direction from the front end to the rear end of the golf club head. The Z axis is perpendicular to both the X axis and the Y axis.

[0075] The term “geometric centerpoint,” or “geometric center” of the strikeface, as described herein, is defined as a geometric centerpoint of the strikeface perimeter, and at a midpoint of the face height of the strikeface. In the same or other examples, the geometric centerpoint also can be centered with respect to an engineered impact zone, which can be defined by a region of grooves on the strikeface. As another approach, the geometric centerpoint of the strikeface can be located in accordance with the definition of a golf governing body such as the United States Golf Association (USGA)

[0076] The term “transverse direction,” as described herein, refers to a direction on a sheet perpendicular to the roll / grain direction.

[0077] The term “longitudinal direction,” as described herein, is defined as a direction on a sheet parallel to the roll / grain direction.

[0078] The term “adjacent solvus state,” as described herein, is defined as the state the golf club head front body is in after being formed at a temperature between 0° C. and 150° C. below the solvus temperature of the material making up the front body. This state is roughly equivalent to the state achieved by traditional forming processes.

[0079] The term “sub-solvus state,” as described herein, is defined as the state the golf club head front body is in after being formed at a temperature between 150° C. and 325° C. below the solvus temperature of the material making up the front body. The sub-solvus state comprises two sub-states: an intermediate sub-solvus state and a deep sub-solvus state.

[0080] The term “intermediate sub-solvus state,” is defined as the state the golf club head front body is in after being formed at a temperature between 150° C. and 225° C. below the solvus temperature of the material making up the front body.

[0081] The term “deep sub-solvus state,” as described herein, is defined as the state the golf club head front body is in after being formed at a temperature between 225° C. and 325° C. below the solvus temperature of the material making up the front body.

[0082] The term “sub-solvus forming temperature,” as described herein, is defined as the forming temperature that places the golf club head front body is in the sub-solvus state. The sub-solvus forming temperature is between 150° C. and 325° C. below the solvus temperature of the material making up the front body. The sub-solvus forming temperature encompasses both the intermediate sub-solvus forming temperature at 150° C. to 225° C. below the solvus temperature and the deep sub-solvus forming temperature at 225° C. to 325° C.

[0083] The term characteristic time “CT,” as described herein, is defined as a measurement used to determine the amount of time, measured in microseconds (μs), that a golf ball contacts the strikeface at the moment of impact. The characteristic time is measured by impacting a specific spot on the striking surface several times using a small steel pendulum. The characteristic time measurement is for wood-type club heads such as drivers, fairway woods, or hybrids. A computer program measures the amount of time the steel pendulum contacts the strikeface at the moment of impact. CT values were based on the method outlined in the USGA's Procedure for Measuring the Flexibility of a Golf Clubhead. For example, Section 2 of the USGA's Procedure for Measuring the Flexibility of a Golf Clubhead (USGA-TPX3004, Rev. 2.0, Apr. 9, 2019) (the “Protocol For Measuring The Flexibility of A Golf Club Head”).

[0084] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,”“comprising,” and “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. All weight percent (wt %) numbers described below are a total weight percent.

[0085] The general terms used to describe the material properties associated with the disclosed material are provided below. These definitions are regarded as the industry standard and are provided by the professional society of material scientists and material engineers, ASM International.DESCRIPTION

[0086] The golf club heads described herein have a high strength titanium alloy strikeface with a more isotropic crystal structure and more isotropic mechanical properties than conventional strikefaces. The golf club heads have a front body, comprising a strikeface and a return formed of a near alpha alloy, an alpha-beta alloy, or a near beta alloy having a solvus temperature between 700° C. and 1050° C. Forming the front body at a temperature between 150° C. and 325° C. below the solvus temperature, using an increased tonnage to shape the front body, yields a crystalline structure with smaller grain size and reduced directionality compared to materials formed at solvus or adjacent solvus temperatures. Forming at such sub-solvus temperatures require fabrication techniques and equipment capable of applying a magnitude of tonnage not used before to form golf clubs. As the forming temperature is lowered further below the solvus of the metal, the amount of tonnage must be increased. Increasing tonnage and improving other parameters of the forming process (such as tooling) allows the strikeface to be properly formed at a temperature between 150° C. and 325° C. below the solvus temperature. Forming titanium alloys at sub-solvus temperatures as taught herein, creates a more isotropic crystal structure, improving mechanical properties such that alloys previously believed to be unsuitable can now be used in golf applications.

[0087] Titanium is naturally anisotropic and therefore has directionality that can be exacerbated by the forming process. Mitigating directionality in strikefaces is advantageous. Generally, the strikeface experiences higher stress in the crown-to-sole direction than the heel-to-toe direction. The forward portion of both the crown and sole, i.e., the portions that can be made up by the return, experience higher stress in a heel-to-toe direction rather than the crown-to-sole direction. As such, it is desirable to form a front body having both a strikeface and a return with a material having approximately equal mechanical properties in both the crown-to-sole and the heel-to-toe directions. In some embodiments, the mechanical properties may be slightly more desirable (strength and ductility) in one direction (longitudinal or transverse). In such embodiments, the material can be oriented such that the direction having the slightly more desirable mechanical properties extends in the crown-to-sole direction, as the strikeface experiences larger stresses than the return. In one such embodiment the material used to create the front body can be oriented such that the longitudinal direction extends in a crown-to-sole direction. In another such embodiment, the material used to create the front body can be oriented such that the transverse direction extends in a crown-to-sole direction.

[0088] Near alpha alloys, alpha-beta alloys, and near beta alloys advantageously have a strength sufficient to withstand repeated impacts with a golf ball while having a ductility that is sufficiently elastic to provide an efficient energy transfer at impact (i.e., the spring effect) creating high ball speed. The raw material of these alloys has a chemical composition with mechanical properties suitable for use as strikefaces. Traditional fabrication processes used to convert the raw alloy material into a final, net shape, however, significantly deteriorated those mechanical properties. According to the present invention, forming the front body from a near alpha alloy, alpha-beta alloy, or near beta alloy at reduced temperatures, specifically between 150° C. and 325° C. less than the solvus temperature, mitigates that loss and can provide a strikeface that retains up to 98% of the rolled material mechanical properties. Without wanting to be bound by theory, it is believed that forming alloys at sub-solvus temperatures reduce grain size, form more equiaxed grain shapes, and more greatly distributes grain orientation to improve the mechanical properties of the alloy, as described in greater detail below.A. GENERAL DESCRIPTION OF GOLF CLUB HEAD

[0089] A golf club head 100 shown in FIG. 1-8 includes a front body 102 formed from a metal and a rear body 104 formed from metal, composite, or a combination thereof. The rear body 104 can be formed from one or more separately formed composite members 106 and can include one or more weighting members 108 proximate a rear end. The front body 102 and the rear body 104 can form an enclosed hollow interior cavity 110. The golf club head 100 further includes a hosel 101, a crown 112, a sole 114 opposite the crown 112, a heel 116, and a toe 118 opposite the heel 116.

[0090] The front body 102 generally includes a strikeface 122 having a striking surface 123 intended to impact a golf ball, a back surface 124 opposite the striking surface 123, a geometric center 126, an outer edge 128 and a return 130. The back surface 126 borders the enclosed hollow interior cavity 110 of the club head 100. The return 130 can extend rearward from the strikeface 122 such that the return 130 makes up a portion of the crown 112, the sole 114, the heel 116, the toe 118, or a combination of the crown 112 and the sole 114. In some embodiments, as shown in FIGS. 2-3, the return 130 extends rearward from the outer edge 128 to form part the sole 114. In other embodiments, the return 130 can extend rearward from the outer edge 128 to form part of the crown 114. In other embodiments, the return 130 can extend rearward from the outer edge 128 to form both a part of the crown 114 and a part of the sole 114.

[0091] In some embodiments, the return 130 can comprise an impact response modulator 132 (hereafter “JIRM”) monolithically formed with the front body 102. The IRM 132 is positioned in the sole 114 proximate the strikeface 122 to strategically weaken the sole 114, increasing strikeface 122 deflection and improving ball flight performance. The IRM 132 can include a casing that forms one or more walls 134 defining an aperture 136 into the club head 100. The aperture 136 is an opening through the sole 114 that communicates between the environment surrounding the club head 100 and the interior cavity 110 of the club head 100. The IRM 132 further may include an insert 138 positioned within the aperture 136 and formed of a flexible, polymeric material. The above IRM details, are described in U.S. patent application Ser. No. 19 / 090,340, filed on Mar. 25, 2025, U.S. patent application Ser. No. 19 / 212,536, filed on May 19, 2025, U.S. patent application Ser. No. 19 / 255,859, filed on Jun. 30, 2025, and U.S. patent application Ser. No. 19 / 339,232, filed on Sep. 24, 2025, all of which the contents of which are fully incorporated herein.

[0092] The strikeface 122 can define a strikeface thickness measured between the striking surface 123 and the back surface 124 in a direction perpendicular to a loft plane 1015 (FIG. 6). The loft plane 1015 is angled relative to a ground plane 1010. The strikeface 122 can comprise a variable thickness profile. The strikeface 122 can comprise a minimum thickness. The minimum thickness can be between 0.075 inch and 0.125 inch. The minimum thickness can be between 0.075 inch and 0.080 inch, 0.080 inch and 0.085 inch, 0.085 inch and 0.090 inch, 0.090 inch and 0.095 inch, 0.095 inch and 0.100 inch, 0.100 inch 0.105, 0.105 inch and 0.110 inch, 0.110 inch and 0.115 inch, 0.115 inch and 0.120 inch, and 0.120 inch and 0.125 inch. In some embodiments, the minimum thickness can be less than 0.125 inch, less than 0.120 inch, less than 0.115 inch, less than 0.110 inch, less than 0.105 inch, less than 0.100 inch, less than 0.095 inch, less than 0.090 inch, less than 0.085 inch, or less than 0.080 inch. The titanium alloys of the present invention comprise more isotropic mechanical properties due to reduced directionality, created by forming the strikeface at a temperature between 150° C. and 325° C. below the solvus temperature. Accordingly, the thickness of the strikeface can be reduced to increase discretionary mass.

[0093] The center of gravity location, moment of inertia values, and variable face thickness configurations can improve ball speed and related performance characteristics. A thin strikeface 122 can increase discretionary mass, increase ball speed, and improve performance; however, a thinner strikeface 122 typically reduces impacts durability. The front body 102, and therefore the strikeface 122 and the return 130, can be formed from a titanium alloy having a more isotropic crystal structure having smaller, more equiaxed grains and greatly distributed grain orientation. This crystal structure retains the metals rolled mechanical properties that are more equal in the longitudinal and transverse directions. As a result, the finally formed strikeface 122 has mechanical properties that are closer to those of the rolled titanium alloy (higher strength and elasticity). As a result, the thickness of the strikeface 122, can be smaller, saving discretionary mass and improving impact parameters (i.e., providing an improved energy transfer at impact leading to increased ball speed) while maintaining sufficient durability.B. GRAIN ORIENTATION

[0094] A crystal structure of the front body 102 material can affect mechanical properties and therefore durability and fatigue resistance. More specifically, the grain size and grain orientation of each grain relative to adjacent grains can influence the fatigue fracture behavior of the front body 102. A forming temperature between 150° C. and 325° C. below the solvus temperature provides a front body 102 with a crystal structure having a more evenly balanced distribution of both strong and weak orientations, and therefore reduced crystallographic texture and macro-zones. Macro-zones propagate stress, fine line cracks, and overall failure of the strikeface, often at a number of golf ball impact below acceptable standards.

[0095] The front body 102, which was formed at a sub-solvus temperature has a predominant alpha phase, but also includes beta phase. Alpha phase typically exhibits a hexagonal close-packed (HCP) crystal structure that includes true basal planes {0001}, true prismatic planes {1010}, and true pyramidal planes {1120}. True basal planes exhibit strong crystallographic texture in the rolling direction and are associated with high anisotropy, reduced ductility, a higher elastic modulus, and a lower elastic strain capacity. In contrast, true prismatic planes are oriented in a more favorable direction for deformation resulting in a more compliant material response with a lower elastic modulus and larger elastic strain. True pyramidal planes represent grains that are rotated out of the true basal and true prismatic planes. These grains can accommodate even greater elastic strain and, in some cases, promote recovery and recrystallization. Collectively, these planes dictate the material's slip behavior and deformation mechanisms of the material.

[0096] To analyze the crystal structure, both a transverse sample area 200 and a longitudinal sample area 300 can be taken from the front body 102. As shown in FIG. 9, in an exemplary embodiment the transverse sample area 200 is the cross section (cut parallel to surface B) of a transverse tensile bar 202 that extends in a direction perpendicular to the rolling direction (RD). The longitudinal sample area 300 is the cross section (cut parallel to surface C) of a longitudinal tensile bar 302 that extends in a direction parallel to the rolling direction (RD). The aspects of each individual sample area 200, 300 are substantially equivalent across the entirety of the front body 102. As such, each sample area 200, 300 can represent any section of the front body 102 in that respective direction. Each sample area 200, 300 can comprise a height of 56.4 μm and width of 56.4 μm for a sample area of 3181 μm2. Each sample area 200, 300 can comprise a total map resolution of 640,000 pixels within the sample area.

[0097] FIGS. 10-15 depict schematic representations of EBSD (Electron Backscatter Diffraction) analysis of each sample area 200 for an exemplary Ti5325 sample. More specifically, FIGS. 12 and 15 show EBSD analyses of each sample area 200, 300 in an adjacent solvus state, and FIGS. 10-11 and 13-14 show EBSD analyses of the samples in a sub-solvus state. The EBSD images are grain orientation maps illustrating the crystallographic orientations and microstructural features on 2D maps of the surface. The different regions of color depicted in each figure represent a different orientation. According to the present disclosures, the red regions correlates with the true basal orientation, green regions correlate with the true prismatic orientation, and blue regions correlate with the true pyramidal orientation. The EBSD images further comprise intermediate colors. The intermediate colors illustrate orientations that are transitioning between any two of the true orientations. For example, the purple color represents an intermediate orientation between the true basal orientation and the true pyramidal orientation. Intermediate colors include every other color and shade other than true red, true blue, and true green (i.e., light blue, light green, yellow, pink, purple, etc.)

[0098] EBSD images depict the area fraction percentage of each orientation present. Area fraction percentage indicates how much of the scanned area is occupied by grains sharing a specific crystallographic orientation. EBSD images provide a representative 2D section of the material's 3D microstructure. In crystalline materials, the area fraction observed in an EBSD scan reflects the true 3D volume fraction of those orientations. Thus, the color-coded orientation families shown in the EBSD figures not only represent the proportion of the mapped area exhibiting each orientation but also indicate how much of the total material volume contains those orientations. Determining volumetric crystallographic texture content throughout the entire material can be extrapolated from the EBSD area-fraction measurements. Further, in these EBSD figures each color corresponds to one orientation family, and the percentage associated with that color represents the proportion of the total mapped area that exhibits that orientation. This helps quantify how dominant or scarce certain orientations are. Higher area or volume fractions of particular orientations can show preferred grain alignment, while more evenly distributed fractions show a more random or isotropic microstructure.

[0099] FIGS. 10-12, depicts an EBSD analysis for sample area 200. FIGS. 10 and 11 show the EBSD of the material formed at a sub-solvus forming temperature (between 150° C. and 325° C. below the solvus temperature) yielding the sub-solvus state. The grain orientation map of an exemplary front body shows a more balanced distribution of true basal, true prismatic, and true pyramidal orientations, wherein no single orientation of the true basal, true pyramidal, or true prismatic exceeds 30% of the total area fraction. In some embodiments, the total area fraction of each of the true basal, true pyramidal, and true prismatic orientations is less than 15%, 20%, 25%, 35%, 40%, 45%, or 50%. In the sub-solvus state, the true basal orientation percentage (red) is below 30% of the total area fraction. In other embodiments, the true basal orientation percentage is below 5%, below 10%, below 15%, below 20%, below 25%, below 35%, below 40%, below 45%, below 50%, below 55%, or below 60% of the total area fraction. In the deep sub-solvus state, the grains are more equiaxed and uniformly shaped, with no dominant clustering. This combination of grain shape and orientation distribution is indicative of a more isotropic material, with no dominant crystallographic orientation. This absence of crystallographic texture promotes isotropic mechanical behavior, allowing load to be shared evenly among grains. Consequently, both strength and elongation exhibit comparable values in multiple orientations, reflecting the material's overall isotropic response.

[0100] FIG. 10 depicts an EBSD analysis for sample area 200 in the deep sub-solvus state, while FIG. 11 depicts sample area 200 in the intermediate sub-solvus state. A comparison of FIGS. 10 and 11 illustrates how the crystal structure of the material transitions when approaching the solvus temperature. In the intermediate sub-solvus state, partial recovery begins to occur, and the color distribution begins to become less uniform compared to the deep sub-solvus state. The true pyramidal, true basal, and true prismatic orientations are all still present, but their relative fractions begin to shift, and regions of clustering begin to appear. The grains remain more equiaxed, but some early signs of elongation begin to appear, demonstrating a shift to the adjacent solvus state.

[0101] FIG. 12 depicts an EBSD analysis for sample area 200 in the adjacent solvus state, showing the pronounced change in microstructure when compared to the sub-solvus state (FIGS. 10 and 11). In the adjacent solvus state, the microstructure becomes strongly biased towards true basal (red) orientations. In the grain orientation map of an exemplary adjacent solvus state, the true basal percentage (red) is above 60% of the total area fraction. In other embodiments, the true basal percentage is above 40%, above 45%, above 50%, above 55%, above 65%, above 70%, above 75%, above 80%, above 85%, or above 90% of the total area fraction. At the adjacent solvus forming temperature, the grains are elongated and aligned in a banded appearance as shown in FIG. 12. The clustering of alignment and orientation indicates a loss of isotropy and a more directional crystallographic texture. The anisotropic behavior present in the adjacent solvus forming temperature increases directional stiffness and decreases uniformity of mechanical performance of the golf club head. Anisotropy is undesirable for a golf club having a titanium front, strikeface, and adjoining return. The strikeface is subject to higher loading in the crown-to-sole direction than in the heel-to-toe direction, whereas the forward portions of the crown and sole regions (the portions forming the return) experience highest stresses in the heel-to-toe direction. As these regions encounter different principal stress orientations during impact, it is advantageous for the material to exhibit similar mechanical properties in both the crown-to-sole and heel-to-toe directions. As such, a more isotropic material is preferred for the front body of the golf club head to ensure consistent performance across the varying loading conditions experienced during play.

[0102] FIGS. 13-15 depict schematic representations of EBSD analyses for sample area 300. FIGS. 13 and 14 depict the microstructure of the exemplary Ti5325 sample formed at a sub-solvus forming temperature (between 150° C. and 325° C. below the solvus temperature) yielding the sub-solvus state. The grain orientation map of an exemplary front body shows a more balanced distribution of true basal, true prismatic, and true pyramidal orientations, wherein no single orientation of true basal, true pyramidal, or true prismatic orientation exceeds 30% of the total area fraction. In some embodiments, the total area fraction of each of the true basal, true pyramidal, and true prismatic orientations is less than 15%, 20%, 25%, 35%, 40%, 45%, or 50%. In the sub-solvus state, the true pyramidal orientation percentage (blue) is below 30% of the total area fraction. In other embodiments, the true pyramidal orientation percentage is below 5%, below 10%, below 15%, below 20%, below 25%, below 35%, below 40%, below 45%, below 50%, or below 55% of the total area fraction. In the sub-solvus state, the grains are more equiaxed and uniformly shaped, with no dominant clustering. This combination of grain shape and orientation distribution is indicative of a more isotropic material, with no dominant crystallographic orientation.

[0103] FIG. 13 depicts an EBSD analysis for sample area 300 in the deep sub-solvus state, while FIG. 14 depicts sample area 300 in the intermediate sub-solvus state. A comparison of FIGS. 13 and 14 show the crystal structure of the materials transition as it approaches the solvus temperature. At this temperature, partial recovery begins to occur, and the color distribution begins to become less isotropic compared to the deep sub-solvus state. The true pyramidal, true basal, and true prismatic orientations are all still present, but their relative fractions begin to shift, and regions of clustering begin to appear. The grains remain equiaxed, but some early signs of elongation begin to appear, demonstrating a shift to the adjacent solvus state.

[0104] FIG. 15 depicts an EBSD analysis for sample area 300 in the adjacent solvus state, showing the pronounced change in microstructure when compared to the sub-solvus state shown in FIGS. 13 and 14. In the adjacent solvus state, the microstructure becomes strongly biased towards the true pyramidal (blue) orientation. In the grain orientation map of an exemplary adjacent solvus state the true pyramidal percentage (blue) is above 60% of the total area fraction. In other embodiments, the true pyramidal percentage is above 40%, above 45%, above 50%, above 55%, above 65%, above 70%, above 75%, above 80%, above 85%, or above 90% of the total area fraction. At the adjacent solvus forming temperature the grains are elongated and aligned in a banded appearance in FIG. 15. The clustering of alignment and orientation indicates a loss of isotropy and a more directional crystallographic texture. The anisotropic behavior present at the adjacent solvus forming temperature increases directional stiffness and decreases the mechanical performance of the golf club head. For a golf club head incorporating a titanium front body formed from a strikeface and an adjoining return, anisotropy is undesirable. The strikeface is subject to higher loading in the crown-to-sole direction than in the heel-to-toe direction, whereas the forward portions of the crown and sole regions experience the highest stresses in the heel-to-toe direction. As these regions encounter different principal stress orientations during impact, it is advantageous for the material to exhibit similar mechanical properties in both the crown-to-sole and heel-to-toe directions. As such, a more isotropic material is preferred for the front body of the golf club head to ensure consistent performance across the varying loading conditions experienced during play.

[0105] FIG. 12 depicts an EBSD analysis for sample area 200 in the adjacent solvus state, showing the pronounced change in microstructure when compared to the sub-solvus state (FIGS. 10 and 11). In the adjacent solvus state, the microstructure becomes strongly biased towards true basal (red) orientations. In the grain orientation map of an exemplary adjacent solvus state, the true basal percentage (red) is above 60% of the total volume fraction. In other embodiments, the true basal percentage is above 40%, above 45%, above 50%, above 55%, above 65%, above 70%, above 75%, above 80%, above 85%, or above 90% of the total volume fraction. At the adjacent solvus forming temperature, the grains are elongated and aligned in a banded appearance as shown in FIG. 12. The clustering of alignment and orientation indicates a loss of isotropy and a more directional crystallographic texture. The anisotropic behavior present in the adjacent solvus forming temperature increases directional stiffness and decreases uniformity of mechanical performance of the golf club head. Anisotropy is undesirable for a golf club having a titanium front, strikeface, and adjoining return. The strikeface is subject to higher loading in the crown-to-sole direction than in the heel-to-toe direction, whereas the forward portions of the crown and sole regions (the portions forming the return) experience highest stresses in the heel-to-toe direction. As these regions encounter different principal stress orientations during impact, it is advantageous for the material to exhibit similar mechanical properties in both the crown-to-sole and heel-to-toe directions. As such, a more isotropic material is preferred for the front body of the golf club head to ensure consistent performance across the varying loading conditions experienced during play.

[0106] FIGS. 13-15 depict schematic representations of EBSD analyses for sample area 300. FIGS. 13 and 14 depict the microstructure of the exemplary Ti5325 sample formed at a sub-solvus forming temperature (between 150° C. and 325° C. below the solvus temperature) yielding the sub-solvus state. The grain orientation map of an exemplary front body shows a more balanced distribution of true basal, true prismatic, and true pyramidal orientations, wherein no single orientation of true basal, true pyramidal, or true prismatic orientation exceeds 30% of the total volume fraction. In some embodiments, the total volume fraction of each of the true basal, true pyramidal, and true prismatic orientations is less than 15%, 20%, 25%, 35%, 40%, 45%, or 50%. In the sub-solvus state, the true pyramidal orientation percentage (blue) is below 30% of the total volume fraction. In other embodiments, the true pyramidal orientation percentage is below 5%, below 10%, below 15%, below 20%, below 25%, below 35%, below 40%, below 45%, below 50%, or below 55% of the total volume fraction. In the sub-solvus state, the grains are more equiaxed and uniformly shaped, with no dominant clustering. This combination of grain shape and orientation distribution is indicative of a more isotropic material, with no dominant crystallographic orientation.

[0107] FIG. 15 depicts an EBSD analysis for sample area 300 in the adjacent solvus state, showing the pronounced change in microstructure when compared to the sub-solvus state shown in FIGS. 13 and 14. In the adjacent solvus state, the microstructure becomes strongly biased towards the true pyramidal (blue) orientation. In the grain orientation map of an exemplary adjacent solvus state the true pyramidal percentage (blue) is above 60% of the total volume fraction. In other embodiments, the true pyramidal percentage is above 40%, above 45%, above 50%, above 55%, above 65%, above 70%, above 75%, above 80%, above 85%, or above 90% of the total volume fraction. At the adjacent solvus forming temperature the grains are elongated and aligned in a banded appearance in FIG. 15. The clustering of alignment and orientation indicates a loss of isotropy and a more directional crystallographic texture. The anisotropic behavior present at the adjacent solvus forming temperature increases directional stiffness and decreases the mechanical performance of the golf club head. For a golf club head incorporating a titanium front body formed from a strikeface and an adjoining return, anisotropy is undesirable. The strikeface is subject to higher loading in the crown-to-sole direction than in the heel-to-toe direction, whereas the forward portions of the crown and sole regions experience the highest stresses in the heel-to-toe direction. As these regions encounter different principal stress orientations during impact, it is advantageous for the material to exhibit similar mechanical properties in both the crown-to-sole and heel-to-toe directions. As such, a more isotropic material is preferred for the front body of the golf club head to ensure consistent performance across the varying loading conditions experienced during play.C. GRAIN SIZE

[0108] The sample areas 200, 300 further exhibit grain structures that can be depicted as individual grains displayed in a two-dimensional area. Grain size is a metric to analyze the grain structure of metallic materials and may be calculated using standard ASTM grain size measurement guidelines. For golf clubs, small, equiaxed grains provide durability to withstand the stresses of repeated golf ball impacts. Larger grains compromise the integrity of the golf club components, leading to failure in the form of cracking. Specifically, larger grains allow cracks to propagate more easily compared to small grains because there are less grain boundaries to obstruct the propagation of microcracks. The larger grains allow the cracks to follow straighter, more direct paths, accelerating propagation. Conversely, smaller grains obstruct the direct path, making the crack take a more tortuous path that inhibits crack propagation, maintains structural integrity, and improves durability. Therefore, as grain size decreases, mechanical properties, such as ultimate strength and yield strength will increase, relative to the same material having a larger grain structure.

[0109] The forming temperature has a role in determining the grain size of the material. For instance, forming temperatures at or near the solvus temperature of the material (yielding adjacent solvus state) will result in large, elongated grains, while forming at a temperature between 150° C. and 325° C. below the solvus temperature (yielding sub-solvus state) results in relatively small globular grains 142 (i.e., grains with little to no elongation) that are more equiaxed across the sample areas 200, 300. Smaller grains increase yield strength through more boundaries restricting dislocation movement and delaying crack initiation. This in turn increases overall fatigue life. In addition, smaller grains create a more tortuous and longer crack path increasing fatigue life. For a given material, smaller grain sizes in the sub-solvus states can be expressed as a percent grain size reduction compared to larger grain sizes of the adjacent solvus state. Accordingly, a percent grain size reduction is the ratio between the grain size of the sub-solvus state and the grain size of the adjacent solvus state.

[0110] The percent grain size reduction may be applied to the average grain size, median grain size, minimum grain size, and maximum grain size. In some embodiments, the average grain size may comprise a percent grain size reduction below 90%. In other embodiments, the average grain size may comprise a percent grain size reduction below 85%, below 80%, below 75%, below 70%, below 65%, below 60%, below 55%, or below 50%. Further, in some embodiments the average grain size may comprise a percent grain size reduction between 90% and 85%, between 85% and 80%, between 80% and 75%, between 75% and 70%, between 70% and 65%, between 65% and 60%, between 60% and 55%, or between 55% and 50%. The median grain size may comprise a percent grain size reduction below 90%. In other embodiments, the median grain size may comprise a percent grain size reduction below 85%, below 80%, below 75%, below 70%, below 65%, below 60%, below 55%, or below 50%. Further, in some embodiments the median grain size may comprise a percent grain size reduction between 90% and 85%, between 85% and 80%, between 80% and 75%, between 75% and 70%, between 70% and 65%, between 65% and 60%, between 60% and 55%, or between 55% and 50%.

[0111] Decreasing the grain size also results in a higher number of grains per unit area, also known as a grain density. For instance, the number of grains within sample areas 200, 300 can be counted and compared to a baseline value, such as the adjacent solvus state. The adjacent solvus state comprises larger grain sizes, resulting in a lower grain density than the sub-solvus state. For example, in some embodiments, the grain density for an adjacent solvus state may be 0.25 grains per μm2 or lower, while the sub-solvus state comprises a grain density of 0.35 grains per μm2 or higher. Within the sub solvus state the deep sub-solvus state can comprise a grain density of 0.41 grains per μm2 or higher. In these embodiments, the sub-solvus grain density may increase, relative to the adjacent solvus state grain density, by over 100%. In other embodiments, the sub-solvus grain density may increase, relative to the adjacent solvus state grain density, between 40% and 50%, between 50% and 60%, between 60% and 70%, between 70% and 80%, between 80% and 90%, or between 90% and 100%. More grains per unit area results in a larger amount of grain boundaries within the material. This corresponds to increased durability as crack propagation is inhibited by the increased number of grains. Additionally, the smaller and increased number of grains further improves the ultimate strength and yield strength of the material.

[0112] The sample area 200 in the deep sub-solvus embodiment, shown in FIG. 16C, has grains that are more equiaxed in shape. An equiaxed structure produces a material that has equal mechanical properties in all directions. A non-equiaxed grain structure, the result of forming the material at the solvus state, forms a longer column shape, which creates an anisotropic structure, as illustrated in FIG. 16A. This anisotropic structure will have strong and weak directions based on the direction of the columnar grains 140, which for golf club components, i.e., the front body 102 of the present invention, is not desirable. The isotropic, equiaxed structure is beneficial for the front body 102 of the present invention because strength is needed in all directions, due to the sole and / or crown return. The forming temperature of the golf club components influences the grain structure. Specifically, forming at the adjacent solvus state yields a generally non-equiaxed grain structure having columnar grains 140 resulting in a higher crystallographic texture. The non-equiaxed grain structure lacks substantially equal strength in all directions. While materials formed at a temperature between 150° C. and 325° C. below the solvus temperature (yielding sub-solvus state), such as the grain structure depicted in FIG. 16B, has a more equiaxed, globular grain structure. In general, materials formed at a temperature between 150° C. and 325° C. below the solvus temperature yields grain structures with small grains that are more equiaxed, providing improved strength and therefore durability to withstand stresses from repeated golf ball impacts.D. MECHANICAL PROPERTIES

[0113] Generally, the strikeface 122 experiences higher stress in the crown-to-sole direction than the heel to toe direction. However, the forward portion of both the crown and sole, i.e., the portions that can form the return 130, experience higher stress in a heel to toe direction. As such, having approximately equal mechanical properties in both directions can be desirable for a golf club head 100 having a front body 102 formed from a strikeface 122 and a return 130. Further, the golf club head of the present invention can have a front body 102 with mechanical properties close, to if not the same as, that of the rolled material. Materials formed at a temperature between 150° C. and 325° C. below the solvus temperature have greater grain density, leading to improved strength, and balance plane orientation distribution providing a more isotropic material with approximately equal mechanical properties in the transverse and longitudinal direction.

[0114] The strength of a strikeface material, such as titanium alloy, is defined as a relationship between yield strength and elongation. Strength is related to durability, which is quantified by the amount of hits a strikeface can withstand before failure. Generally, a high yield strength, high elongation, and high toughness result in a more durable strikeface. This is because the high yield strength is associated with the ability to withstand stress without breaking, while high elongation allows for a material to withstand more permanent deformation before breaking. Toughness is the materials resistance to fracture without absorbing energy. A low yield strength renders the strikeface unable to withstand repeated stresses of impact with a golf ball, and a strikeface with a low elongation will be too brittle. Another key mechanical property for a strikeface metal, related to yield strength and elongation, is the elasticity modulus, which describes the stiffness of the material. These mechanical properties are important to golf clubs as thinner / lower weight strikefaces allow for more design freedom by creating discretionary mass, but the strikeface must retain durability. Forming the strikeplate material at reduced temperatures, specifically between 150° C. and 325° C. less than the solvus temperature, mitigates the loss of mechanical properties, providing a strikeface with up to 98% of the rolled material mechanical properties.

[0115] The mechanical properties of a golf club strikeface must also result in a strikeface that conforms to the rules of golf. For instance, characteristic time (CT) is an element that relates to energy transfer and is limited by the rules of golf. Higher CT values equate to greater energy transfer, which is why CT is regulated by the rules of golf and monitored when designing new golf clubs. CT is affected by both the structural design and the materials selected for the golf club. For instance, a higher modulus material is stiffer, which generally results in a lower CT value.E. MATERIALS—CHEMISTRY AND MECHANICAL PROPERTIES

[0116] The strikeface is the only component intended to make direct contact with the golf ball and therefore absorbs a significant amount of energy to create ball speed and distance. Near alpha, alpha-beta, and beta alloys comprise mechanical properties suitable for use in the strikeface of a golf club head. Further, these alloys require shorter and simpler heat treatments to achieve the desired mechanical properties.

[0117] The strikeface, and therefore the front body and the return, can be formed from a front body material, classified as a near alpha, an alpha-beta, or a beta alloy. The classification of each material, and therefore the properties and reaction of each material, is dependent on the total wt % of each element within the given material. For example, the solvus temperature is determined by the amount of α and β stabilizers in the alloy. As the total wt % of the β stabilizers (such as vanadium and molybdenum) increases, the solvus temperature decreases. In contrast, as the total wt % of α stabilizers (such as aluminum) increases, the solvus temperature increases.

[0118] The material can have a total wt % of a stabilizer aluminum between 4 wt % and 9 wt %. The total wt % of aluminum can be between 4.0 wt % and 9.0 wt %, 4.1 wt % and 8.9 wt %, 4.2 wt % and 8.8 wt %, 4.3 wt % and 8.7 wt %, 4.4 wt % and 8.6 wt %, 4.5 wt % and 8.5 wt %, 4.6 wt % and 8.4 wt %, 4.7 wt % and 8.3 wt %, 4.8 wt % and 8.2 wt %, 4.9 wt % and 8.1 wt %, 5.0 wt % and 8.0 wt %, 5.1 wt % and 7.9 wt %, 5.2 wt % and 7.8 wt %, 5.3 wt % and 7.7 wt %, 5.4 wt % and 7.6 wt %. 5.5 wt % and 7.5 wt %, 5.6 wt % and 7.4 wt %, 5.7 wt % and 7.3 wt %, 5.8 wt % and 7.2 wt %, 5.9 wt % and 7.1 wt %, 6.0 wt % and 7.0 wt %, 6.1 wt % and 6.9 wt %, 6.2 wt % and 6.8 wt %, 6.3 wt % and 6.7 wt %, 6.4 wt % and 6.6 wt %. In some embodiments the total wt % of aluminum can be between 4.0 wt % and 4.2 wt %, 4.2 wt % and 4.4 wt %, 4.4 wt % and 4.6 wt %, 4.6 wt % and 4.8 wt %, 4.8 wt % and 5.0 wt %, 5.0 wt % and 5.2 wt %, 5.2 wt % and 5.4 wt %, 5.4 wt % and 5.6 wt %, 5.6 wt % and 5.8 wt %, 5.8 wt % and 6.0 wt %, 6.0 wt % and 6.2 wt %, 6.2 wt % and 6.4 wt %, 6.4 wt % and 6.6 wt %, 6.6 wt % and 6.8 wt %, 6.8 wt % and 7.0 wt %, 7.0 wt % and 7.2 wt %, 7.2 wt % and 7.4 wt %, 7.4 wt % and 7.6 wt %, 7.6 wt % and 7.8 wt %, 7.8 wt % and 8.0 wt %, 8.0 wt % and 8.2 wt %, 8.2 wt % and 8.4 wt %, 8.4 wt % and 8.6 wt %, 8.6 wt % and 8.8 wt %, or 8.8 wt % and 9.0 wt %. The presence of aluminum in Ti alloys can promote stability of its α phase at higher temperatures, allowing for higher temperature heat treatment to occur, improving strength and corrosion resistance by reducing stress.

[0119] The material can have a total wt % of β stabilizer vanadium between 1.5 wt % and 3.5 wt %. The wt % of β stabilizer vanadium can be between 1.5 wt % and 3.5 wt %, 1.6 wt % and 3.4 wt %, 1.7 wt % and 3.3 wt %, 1.8 wt % and 3.2 wt %, 1.9 wt % and 3.1 wt %, 2.0 wt % and 3.0 wt %, 2.1 wt % and 2.9 wt %, 2.2 wt % and 2.8 wt %, 2.3 wt % and 2.7 wt %, or 2.4 wt % and 2.6 wt %. In some embodiments, the total wt % of β stabilizer vanadium can be between 1.5 wt % and 1.7 wt %, 1.7 wt % and 1.9 wt %, 1.9 wt % and 2.1 wt %, 2.1 wt % and 2.3 wt %, 2.3 wt % and 2.5 wt %, 2.5 wt % and 2.7 wt %, 2.7 wt % and 2.9 wt %, 2.9 wt % and 3.1 wt %, 3.1 wt % and 3.3 wt %, or 3.3 wt % and 3.5 wt %.

[0120] The material can have a solvus temperature above 700° C. and below 1050° C. In certain embodiments, the solvus temperature can be between 700° C. and 725° C., 725° C. and 750° C., 750° C. and 775° C., 775° C. and 800° C., 800° C. and 825° C., 825° C. and 850° C., 850° C. and 875° C., 875° C. and 900° C., 900° C. and 925° C., 925° C. and 950° C., 950° C. and 975° C., 975° C. and 1000° C., 1000° C. and 1025° C., or 1025° C. and 1050° C. In certain embodiments, the solvus temperature can be below 800° C., below 825° C., below 850° C., below 875° C., below 900° C. and 925° C., below 950° C., below 975° C., below 1000° C., or below 1025° C. Similar to the solvus temperature the mechanical properties of the alloy can be determined by the chemical make-up of the alloy.1. 6-22-22

[0121] In some embodiments, the front body can be formed from titanium alloy 6-22-22 and its subtype derivatives depending upon its elements (including the wt % of impurities such as hydrogen and key action elements such as molybdenum and aluminum). 6-22-22 can have a solvus temperature between 900° C. and 1000° C. and a Moeq value of −0.80. The mechanical properties of titanium alloy 6-22-22 are modified through alloying and metal working to produce a strikeface with high strength and increased durability. The titanium alloy can be an α-β titanium (α-β Ti) alloy. Specifically, the α-β Ti alloys of the present invention each have a minimum yield strength of 170 ksi, a minimum tensile strength of 180 ksi, a minimum elongation of 5.0%, a Young's Modulus between 18 and 25 Mpsi, and a density between 4.410 g / cm3 and 4.710 g / cm3.

[0122] All numbers described below regarding composition describe weight as a total weight percent (wt %). In some embodiments, α-β Ti alloy 6-22-22 can have a total weight percent of α-stabilizer aluminum between 5.0 wt % to 7.0 wt %. 6-22-22 can have a total weight percent of tin between 1.0 wt % to 3.0 wt %, and a total weight percent of α-stabilizer zirconium between 1.0 wt % to 3.0 wt %. A total weight percent of 3-stabilizer molybdenum between 1.0 wt % to 3.0 wt %. A total weight percent of β-stabilizer chromium between 1.0 wt % to 3.0 wt %. A total weight percent of carbon less than or equal to 0.05 wt %. A total weight percent of nitrogen less than or equal to 0.03 wt %. A total weight percent of oxygen less than or equal to 0.14 wt %. A total weight percent of hydrogen less than or equal to 0.0125 wt %. The combination of α and β stabilizers, as discussed above, allows the α-β Ti alloys to be formed into durable lightweight strikeface. The composition of the front body material directly affects the way the material reacts during the formation process.2. Ti5325

[0123] In some embodiments, the front body can be formed from Ti5325 and its subtype derivatives depending upon its elements (including the wt % of impurities such as hydrogen and key action elements such as molybdenum and aluminum). Ti5325 can have a solvus temperature between 900° C. and 950° C. and a Moeq value of −2.99. The mechanical properties of Ti5325 are modified through alloying and metal working to produce a strikeface with high strength and increased durability.

[0124] In some embodiments, Ti5325 can have a total weight percentage of α-stabilizer aluminum between 3.5 wt % to 6.5 wt %. The presence of aluminum in Ti alloys can promote stability of its α phase at higher temperatures, improving strength and corrosion resistance by reducing stress. A total weight percent of β-stabilizer vanadium between 2.0 wt % to 4.0 wt %. A total weight percent of oxygen between 0.10 wt % and 0.30 wt %. A total weight percent of iron between 1.5 wt % and 3.5 wt %.

[0125] The grain structure of Ti5325 varies according to the forming temperature. For instance, at the adjacent solvus state the adjacent solvus average grain size may be between 3.87 μm and 4.97 μm. Additionally, grains structures formed at the sub-solvus state may produce a sub-solvus average grains size between 2.11 μm and 3.55 μm. In some embodiments, the sub-solvus average grain size may be between 2.55 μm to 3.10 μm. These grain sizes result in a percent grain size reduction from the adjacent solvus average grain size to the sub-solvus average grain size between 42% and 92%. In some embodiments, the percent grain size reduction from the solvus average grain size to the sub-solvus average grain size may be between 55% and 70%. The reduction in grain size increases the grain density within the material, wherein Ti5325 may comprise a grain density increase, relative to the adjacent solvus state, between 35% and 115%. Further, for materials in the intermediate sub-solvus state, the grain density increase, relative to the adjacent solvus state, may be between 35% and 50%. Materials in the deep sub-solvus state may have the grain density increase, relative to the adjacent solvus state, between 60% and 115%.3. HST 220

[0126] In some embodiments, the strikeface can be formed from α-β Ti alloy HST-220. α-β Ti alloy HST-220 has a solvus temperature of 980° C. and a Moeq value of −2.1657. HST-220 can have a total weight percent of α-stabilizer aluminum between 6.5 wt % to 8.5 wt %, a total weight percent of β-stabilizer molybdenum between 1.8 wt % to 3.2 wt %, a total weight percent of β-stabilizer iron less than or equal to 0.35 wt %, a total weight percent of α-stabilizer oxygen less than or equal to 0.2 wt %, a total weight percent of α-stabilizer carbon less than or equal to 0.15 wt %, a total weight percent of α-stabilizer nitrogen less than or equal to 0.1 wt %, a total weight percent of 3-stabilizer hydrogen less than or equal to 0.03 wt %, a total weight percent of β-stabilizer chromium between 1.0 wt % to 2.5 wt %, and a total weight percent of β-stabilizer silicon between 0.2 wt % to 0.3 wt %. α-β Ti alloy HST-220 can have a yield strength between 165 ksi to 187 ksi, an ultimate strength between 180 ksi to 220 ksi, an elongation at break between 5% to 14%, and a modulus of elasticity between 20 Mpsi to 35 Mpsi.4. T9S+

[0127] In some embodiments, the strikeface can be formed from titanium alloy T9S+ and its subtype derivatives depending upon its elements (including the wt % of impurities such as hydrogen and key action elements such as molybdenum and aluminum). T9S+ can have a solvus temperature between 1000° C. and 1050° C. and a Moeq value of −7.16. The mechanical properties of T9S+ are modified through alloying and metal working to produce a strikeface with high strength and increased durability. In some embodiments, the strikeface can be formed from near alpha titanium alloy T9S+. T9S+ can have a total weight percent of α-stabilizer aluminum between 7.8 wt % and 8.5 wt %, a total weight percent of β-stabilizer vanadium between 1.00 wt % and 1.50 wt %, a total weight percent of 0-stabilizer iron less than or equal to 0.40 wt %, a total weight percent of α-stabilizer oxygen less than or equal to 0.3 wt %, a total weight percent of α-stabilizer nitrogen less than or equal to 0.5 wt %, and a total weight percent of β-stabilizer silicon between 0.15 wt % to 0.25 wt %.F. METHOD OF MANUFACTURING

[0128] Forming the front body at a temperature between 150° C. and 325° C. below the solvus temperature preserves the mechanical properties of the material and provides a crystalline structure that is formed of small grains that are more equiaxed, providing isotropic properties. However, this lower than typical forming temperature requires other aspects of the manufacturing method to be altered. The tooling, as well as the temperature and the pressure at which the strikeface is formed, provides a strikeface with mechanical properties close to if not the same as the rolled material. The method of forming the front body 150° C. and 325° C. below solvus yields a strikeface with a crystalline structure having isotropic properties that allow strikeface thickness to be reduced without sacrificing strength and durability. Specifically, the tooling, design, added tonnage, and the forming temperature provides a strikeface with mechanical properties close to if not the same as the mechanical properties of the rolled material.

[0129] Near alpha alloys, alpha-beta alloys, and near beta alloys have a unique combination of strength and ductility. These alloys have a solvus temperature less than 1050° C. The method of manufacturing of the present invention involves forming the strikeface at a temperature between 150° C. and 325° C. less than the solvus temperature. This forming temperature lessens the impact the forming has on the mechanical properties. The strikeface is formed at a temperature between 150° C. and 155° C., 155° C. and 160° C., 160° C. and 165° C., 165° C. and 170° C., 170° C. and 175° C., 175° C. and 180° C., 180° C. and 185° C., 185° C. and 190° C., 190° C. and 195° C., 195° C. and 200° C., 200° C. and 205° C., 205° C. and 210° C., 210° C. and 215° C., 215° C. and 220° C., 220° C. and 225° C., 225° C. and 230° C., 230° C. and 235° C., 235° C. and 240° C., 240° C. and 245° C., 245° C. and 250° C., 250° C. and 255° C., 255° C. and 260° C., 260° C. and 265° C., 265° C. and 270° C., 270° C. and 275° C., 275° C. and 280° C., 280° C. and 285° C., 285° C. and 290° C., 290° C. and 295° C., 295° C. and 300° C., 300° C. and 305° C., 305° C. and 310° C., 310° C. and 315° C., 315° C. and 320° C., or 320° C. and 325° C., less than the solvus temperature. Forming significantly below (150° C. and 325° C.) the solvus temperature preserves the rolled material mechanical properties and crystallographic structure.

[0130] Forming the strikeface at the temperature range disclosed above helps retain the mechanical properties of the rolled material. However, forming the strikeface at this temperature range using traditional forming parameters (i.e., pressure and tooling geometry) yields a strikeface without the desired dimensions. The strikeface has a propensity to “springback” or partially return to an original contour and shape. This issue is overcome by altering the tooling design, increasing the pressure used to form the strikeface, or a combination thereof.

[0131] To account for springback, the strikeface may be deformed beyond the final shape. A strikeface for a wood-type club head, for example, will have curvatures known as bulge and roll. According to the present disclosure, the tooling used to form the strikeface can be configured to impart excessive deformation beyond the final shape, so that when the strikeface is released from the tooling it will revert to a shape that is closer to the desired final shape. Additionally, the tooling can be configured to yield a strikeface thicker than desired. Milling can then be applied to both the front and the back of the strikeface to arrive at the desired curvature.

[0132] Further, traditionally the press used to form a strikeface exerts pressure on the strikeface. The traditional process of forming a strikeface involves using a 300 ton press. Increasing that pressure can temper the springback effect on the strikeface. The method disclosed herein can include press tonnages in excess of 300 tons. In some embodiments a 700-800 ton press can be used to form a strikeface. In some embodiments, an 800-900 ton press can be used to form a strikeface. In one exemplary embodiment, an 800 ton press can be used to form a strikeface. The increased force can overcome the springback of the strikeface. The increase pressure can be used with the tooling design described above or with traditional tooling, depending on the degree of springback that particular material is prone to.

[0133] The material may oxidate during manufacturing. Oxidation can form during formation. Oxidation of titanium results in a strikeface with a brittle, oxygen-enriched outer surface that allows cracks to easily form and propagate. In some embodiments, the strikeface can be sprayed with an antioxidant coating. The use of an antioxidant coating, along with forming the strikeface at a lower temperature, can prevent the formation of an oxide layer. In other embodiments, the strikeface can be formed to have a thickness larger than desired, wherein a sacrificial top layer is removed by mechanical (i.e., cutting or grinding) or chemical (i.e., pickling) means.G. EXAMPLES1. Ti5325 Grain Orientation Example

[0134] This example illustrated the effects of forming temperature on the crystalline structure of Ti5325. Three samples of Ti5325 were formed at different temperatures. The solvus temperature of these samples was approximately 925° C. Sample 1 was formed at 830° C., an adjacent solvus forming temperature (95° C. below solvus). Sample 2 was formed at 730° C., an intermediate sub-solvus forming temperature (195° C. below solvus). Sample 3 was formed at 680° C., a deep sub-solvus forming temperature (245° C. below solvus). All three samples were analyzed in both the longitudinal and transverse direction with an EBSD microscope to compare the unique crystalline structures of each sample. Each sample has a grain orientation map that was evaluated over a sample area of 3,181 μm2.

[0135] Each sample was analyzed to determine the distribution of crystallographic orientations using color-coded EBSD figures, which depict the area fraction percentage of each orientation present. Area fraction percentage indicated how much of the scanned area is occupied by grains sharing a specific crystallographic orientation. Each color corresponded to one orientation family, and the percentage associated with that color represents the proportion of the total mapped area that exhibited that orientation. This helped quantify how dominant or scarce certain orientations are. Higher area fractions of particular orientations show preferred grain alignment, while more evenly distributed fractions show a more random or isotropic microstructure

[0136] Sample 1, seen in FIGS. 12 (longitudinal direction) and 15 (transverse direction), had a crystalline structure with a biased distribution of true basal, true prismatic, and true pyramidal orientations dominated by a single true orientation. The grain orientation map of sample 1, in the longitudinal direction (FIG. 12) comprised 65.15% true basal orientation (red), 4.50% true prismatic orientation (green), and 3.11% true pyramidal orientation (blue). The grain orientation maps of sample 1, in the transverse direction (FIG. 15), comprised 3.49% true basal orientation (red), 8.08% true prismatic orientation (green), and 79.34% true pyramidal orientation (blue). The grain orientation map of sample 1 illustrated that both directions were dominated by a single orientation (i.e. true basal for longitudinal and true pyramidal for transverse). The domination of the crystalline structure by a singular true orientation (depicted by the large clusters of single colored elongated grains) yielded directionality. This directionality created high strength in a first direction and low strength in a second direction, making the material unsuitable for a front body formed from a strikeface and a return.

[0137] Sample 2, seen in FIGS. 11 (longitudinal direction) and 14 (transverse direction), had a crystalline structure with a slightly more balanced distribution of true basal, true prismatic, and true pyramidal orientations with small groups of clumping. The grain orientation map of sample 2, in the longitudinal direction (FIG. 11) comprised 32.45% true basal orientation (red), 8.79% true prismatic orientation (green), and 4.87% true pyramidal orientation (blue). The grain orientation map of sample 2, in the transverse direction (FIG. 14), comprised 3.55% true basal orientation (red), 45.65% true prismatic orientation (green), and 24.60% true pyramidal orientation (blue). The grain orientation maps of sample 2 illustrated that true pyramidal, true basal, and true prismatic orientations were all present, but their relative fractions began to shift, and regions of clustering dissipated. The grains are closer to equiaxed, but some still remained at least partially elongated. In the transverse direction in particular the dominance of the true pyramidal orientation did normalize, only for the true prismatic orientation (green) to creep towards domination at 45.65%. This started to normalize the mechanical properties of in both directions.

[0138] Sample 3, seen in FIGS. 10 (longitudinal direction) and 13 (transverse direction), had a crystalline structure with a balanced distribution of true basal, true prismatic, and true pyramidal orientations. The grain orientation map of sample 3, in the longitudinal direction (FIG. 10) comprised 24.72% true basal orientation (red), 11.67% true prismatic orientation (green), and 16.39% true pyramidal orientation (blue). The grain orientation map of sample 3, in the transverse direction (FIG. 13), comprised 9.20% true basal orientation (red), 22.68% true prismatic orientation (green), and 29.61% true pyramidal orientation (blue). The grain orientation maps of sample 3 illustrated that true pyramidal, true basal, and true prismatic orientations were all relatively balanced. The grains were closer to equiaxed, with minimal clumping in both directions. The lower forming temperature of sample 3 yielded a balanced distribution of true basal, true prismatic, and true pyramidal orientations, wherein no single orientation of the true basal, true pyramidal, or true prismatic orientation exceeds 300 of the total area fraction. This orientation distribution indicated an isotropic material with no dominant crystallographic orientation. This provided isotropic mechanical properties in both the transverse and longitudinal direction.2. Ti5325 Example 1

[0139] In one example, two faceplates were formed from Ti5325 at each of the following temperatures: 550° C., 630° C., 650° C., 675° C., 730° C., 780° C., 830° C., and 900° C. The solvus temperature of these samples was approximately 925° C. Following the faceplate formation, each faceplate was analyzed to determine its mechanical properties. The mechanical properties of each sample are shown below in Table 1 and Table 2. Table 1 shows the mechanical properties of each sample cut in the longitudinal direction and Table 3 shows the mechanical properties of each sample cut in the transverse direction.TABLE 15325 Longitudinal Mechanical Properties by Forming TemperatureAreaunderTemper-YieldUltimateElon-curveatureStrengthStrengthgationModulusYield ×past(° C.)(ksi)(ksi)%(Mpsi)ElongationyieldBaseline15517014.016.02170227555015517015.016.02325243863015416815.516.02387249665015416816.015.82464257673015116515.515.62341244978014816316.815.52486261283014716215.515.1227923959001571788.115.512721357TABLE 25325 Transverse Mechanical Properties by Forming TemperatureAreaunderTemper-YieldUltimateElon-curveatureStrengthStrengthgationModulusYield ×past(° C.)(ksi)(ksi)%(Mpsi)ElongationyieldBaseline16817716.518.12772284655017017916.819.02848292763016817717.918.23013308765016817516.118.02697275773016517317.218.12838290978016417211.717.4191419638301611706.617.0106310939001671783.816.7633654As shown above in Tables 1 and 2, and illustrated in FIG. 17-22, the faceplate formed between 625° C. and 725° C. had the most desirable mechanical properties for application in golf. A downward trend in strength (ultimate and tensile) was experienced in the samples formed at 730° C. and above. Even though the sample formed at 900° C. does not follow this trend, the drastic dip in elongation indicates an extremely brittle material, making it unsuitable for application in golf. In the application of golf, the striking surface must be formed from a material well balanced in both strength and elongation. Therefore, the Yield×Elongation column, as shown above in Tables 1 and 2, and depicted in FIG. 21-22, was used to determine the ideal forming temperature for this example. As shown, as the forming temperature nears the solvus temperature (825° C. and above) the Yield x Elongation drastically decreases. The exact trend varies between the two directions. As such, the ideal forming temperature was determined based on the balance of the two (i.e., the forming temperature that yielded roughly the same values in both directions (a forming temperature between 650° C. and 735° C.). As such, it was determined that forming the faceplate at a temperature between 190° C. and 275° C. below the solvus temperature yielded the most desirable mechanical properties for the application of Ti5325 in a golf club head.3. Ti5325 Grain Size Example

[0141] Ti5325 illustrates the effect of forming temperature on grain size and its overall effects on the mechanical properties. In one example, three samples of Ti5325, which had a solvus temperature of approximately 925° C., were formed at different temperatures. Specifically, Sample 1 was formed at 830° C. Sample 2 was formed at 730° C. Sample 3 was formed at 680° C. Sample 1 was at the adjacent solvus state, and Samples 2 and 3 were at the sub-solvus state. All three samples were analyzed in both the longitudinal and transverse direction by an EBSD microscope to view their unique grain structures and measure the grain sizes of each sample. The grain structures were evaluated over a sample area of 3,181 μm2.

[0142] Sample 1, at the adjacent solvus state, produced an average grain size of 4.37 μm and a median grain size of 3.64 μm, in the longitudinal direction. The transverse direction had an average grain size of 4.47 μm, with a median grain size of 3.19 μm. Further, the sample area comprised 779 total grains in the longitudinal direction and 785 total grains in the transverse direction, which equated to a grain density of 0.24 grains / μm2 in the longitudinal direction and 0.25 grains / μm2 in the transverse direction.

[0143] Sample 2, at the sub-solvus state, produced an average grain size of 2.86 am and a median grain size of 2.51 μm, in the longitudinal direction. The transverse direction had an average grain size of 2.91 μm, with a median grain size of 2.48 μm. This represents percent grain size reductions for the average grain size of 65.4% in the longitudinal direction and 65.1% in the transverse direction, relative to Sample 1. Further, the sample area comprised 1,133 total grains in the longitudinal direction and 1,102 total grains in the transverse direction, which equated to a grain density of 0.36 grains / μm2 in the longitudinal direction and 0.35 grains / μm2 in the transverse direction.

[0144] Sample 3, at the sub-solvus state, produced an average grain size of 2.61 am and a median grain size of 2.21 μm, in the longitudinal direction. The transverse direction had an average grain size of 3.05 μm, with a median grain size of 2.65 am. This represents percent grain size reductions for the average grain size of 59.7% in the longitudinal direction and 68.2% in the transverse direction, relative to Sample 1. Further, the sample area comprised 1,289 total grains in the longitudinal direction and 1,635 total grains in the transverse direction, which equated to a grain density of 0.41 grains / μm2 in the longitudinal direction and 0.51 grains / μm2 in the transverse direction.

[0145] The reduction in grain size from Sample 1 to Samples 2 and 3 allowed for an increased grain density, which may correspond to increased durability. Specifically, Samples 2 and 3 saw a grain density increase, compared to sample 1, of 45% and 65%, respectively in the longitudinal direction, a grain density increase of 40% and 108%, respectively, in the transverse direction. This decrease of grain size and corresponding increase in grain density can be attributed to the lower forming temperatures of Samples 2 and 3, which resulted in samples being in the sub-solvus state, while Sample 1 was in the adjacent solvus state.4. 6-22-22 Example

[0146] Similar to the Ti5325 Example discussed above, 6-22-22 has shown to have desirable characteristics for golf faceplates when compared to traditionally used faceplate materials, such as traditionally formed T9S+. In one example, two faceplates were formed from 6-22-22 at each of the following temperatures: 550° C., 600° C., 625° C., 650° C., 675° C., 700° C., 750° C., 800° C. The solvus temperature of these samples was approximately 960° C. Following the faceplate formation, each faceplate was analyzed to determine its mechanical properties. The mechanical properties of each sample are shown below in Table 3 and Table 4. Table 3 shows the mechanical properties of each sample cut in the longitudinal direction and Table 5 shows the mechanical properties of each sample cut in the transverse direction.TABLE 36-22-22 Longitudinal MechanicalProperties by Forming TemperatureAreaunderTemper-YieldUltimateElon-curveatureStrengthStrengthgationModulusYield ×past(° C.)(ksi)(ksi)%(Mpsi)ElongationyieldBaseline160.5165.52.916.6457465550158162.54.316.5672681600156.5163.55.516.0861880625157164.54.816.27467646501581687.316.3114611826751541594.421.46786897001471588.017.911761220750137.51498.315.3113411828001381465.315.4725746TABLE 46-22-22 Transverse Direction MechanicalProperties by Forming TemperatureAreaunderTemper-YieldUltimateElon-curveatureStrengthStrengthgationModulusYield ×past(° C.)(ksi)(ksi)%(Mpsi)ElongationyieldBaseline16617912.819.02110219355016818013.819.3231023936001651759.319.31526157062516617914.019.32324241565016517813.819.22262235567515117616.519.12483269470015917217.319.42734285175015016216.519.32475257080014815815.318.122572329As shown above in Tables 3 and 4 and illustrated in FIG. 23-28, the faceplate formed between 625° C. and 750° C. had the most desirable mechanical properties for 6-22-22 in the application in golf. A steep drop (over 50 ksi / 50) in yield strength, in both the transverse and longitudinal directions, was experienced in the samples formed at 650° C. and above. However, in the application of golf, the striking surface must be formed from a material well-balanced in both strength and elongation. Therefore, the Yield x Elongation column, as shown above in Tables 3 and 4, and depicted in FIG. 27-28, was also taken into consideration for this example. The exact trend varies between the two directions. As such, the ideal forming temperature was determined based on the balance of the two (i.e., the forming temperature that yielded roughly the same values in both directions). In this example the use of a forming temperature over 700° C. was found to be unsatisfactory as it was the start of a downward trend in the transverse direction. As such, it was determined that forming the faceplate at a temperature between 210° C. and 335° C. below the solvus temperature yielded the most desirable mechanical properties for the application of Ti 6-22-22 in a golf club head.5. Ti52AFS Example

[0148] In another example, two faceplates were formed from Ti52AFS at each of the following temperatures: 550° C., 650° C., 730° C., 780° C., 830° C., and 900° C. The solvus temperature of these samples was approximately 960° C. Following the faceplate formation, each faceplate was analyzed to determine its mechanical properties. The mechanical properties of each sample are shown below in Table 5 and Table 6. Table 5 shows the mechanical properties of each sample cut in the longitudinal direction and Table 6 shows the mechanical properties of each sample cut in the transverse direction.TABLE 5Ti52AFS First Direction MechanicalProperties by Forming TemperatureAreaunderTemper-YieldUltimateElon-curveatureStrengthStrengthgationModulusYield ×past(° C.)(ksi)(ksi)%(Mpsi)ElongationyieldBaseline12914815.516.22000214755013815314.716.82029213965013715116.320.52233234773013515014.016.71890199578013214715.216.52006212083012814416.316.32086221790012914415.516.420002116TABLE 6Ti52AFS Second Direction MechanicalProperties by Forming TemperatureAreaunderTemper-YieldUltimateElon-curveatureStrengthStrengthgationModulusYield ×past(° C.)(ksi)(ksi)%(Mpsi)ElongationyieldBaseline16116914.820.22383244255016317616.320.62657276365016117216.320.52624271473015917114.020.02226231078015816914.520.42291237183015316615.020.42295239390014816214.820.121902294As shown above in Tables 5 and 6 and illustrated in FIG. 29-32, a strikeface made of Ti52AFS and formed between 650° C. and 700° C. had the most desirable mechanical properties for application in golf. The yield strength decreased as the forming temperature increased. However, in the application of golf, the striking surface must be formed from a material well-balanced in both strength and elongation. Therefore, the Yield x Elongation column, as shown above in Tables 5 and 6, was also taken into consideration for this example. The Yield x Elongation follows a similar trend to the yield strength and trends downward as the forming temperature nears solvus. As such, it was determined that forming the faceplate at a temperature between 260° C. and 315° C. below the solvus temperature yielded the most desirable mechanical properties for the application of Ti52AFS in a golf club head.

[0150] Additionally, the grain structure of Ti52AFS was analyzed at two of the forming temperatures, 830° C. and 730° C. At 830° C. (adjacent solvus state) the adjacent solvus average grain size was between 5.0 μm and 5.5 μm. Grain structures formed 730° C. (sub-solvus state) produced a sub-solvus average grain size between 3.9 μm and 4.9 μm. These grain sizes result in a percent grain size reduction between 71% and 98% for materials in the sub-solvus state. Reducing the grain size increases the grain density within a material, wherein Ti52AFS may comprise a grain density increase, relative the adjacent solvus state, between 75% and 120% for materials in the sub-solvus state. The reduced grain size indicated the increased yield strength, as more boundaries restricted dislocation movement and delayed crack initiation.6. 5325 Durability Example

[0151] A test was conducted to compare the effect of forming temperature on the strikeface over the course of 2,000 hits or golf ball strikes. However, the data presented is limited to the first 250 hits or ball strikes wherein the majority of the changes take place. The data between 250 and 2,000 hits or ball strikes plateaus and follows a similar progression as the data displayed for 100 to 250 hits. Each club was hit till failure and the number of hits to failure was recorded.

[0152] The golf club heads of this example had a front body formed from Ti 5235 at varying temperatures. A first control club head (hereafter referred to “Control 1”) having a front body formed from 5325 was formed at a temperature of 830° C. (95° C. below the solvus temperature). A second control club head (hereafter referred to “Test 1”) had a front body formed at a temperature of 730° C. (195° C. below the solvus temperature). A third control club head (hereafter referred to “Test 2”) had a front body formed at a temperature of 680° C. (245° C. below the solvus temperature). All three control club heads were oriented in the same direction. The results can be seen below in Table 7.TABLE 7Effect Forming Temperature has on Bulge and Roll RadiusDeformation at 250 Hits of Ti 5325BulgeRollFormingBulgeRadiusRollRadiusTemperatureRadiusChangeRadiusChangeHits to(° C.)(in)(in)(in)(in)FailureControl 1830° C.0.0014-0.5-0.0014-0.8-21310.00191.30.00200.8Test 1730° C.0.0029-2.2-0.0029-1.1-26980.00372.40.00371.9Test 2680° C.0.0026-1.4-0.0026-0.69-27810.0291.70.00310.69

[0153] As shown in Table 7, the deformation in roll radius (Roll Radius Change) after 250 hits improved by 13.75% from Control 1 to Test 2. While the deformation in bulge radius (Bulge Radius Change) did decline, the drastic 30.50% improvement in hits till failure of Test 2 over Control 1 displayed the improvement in strength and elasticity created by forming the front body of the golf club head at a temperature (approx.) 250° C. degrees below solvus. This drastic improvement in hits till failure displayed the improvement in strength and elongation as the forming temperature decreased.CLAUSES

[0154] Clause 1. A golf club head comprising: a crown, a sole opposite the crown, a toe end, a heel end opposite the toe end, and a rear end; a rear body; a front body formed of a front body material having a solvus temperature between 700° C. and 1050° C., comprising: a strikeface having a striking surface and a back surface opposite the striking surface; and a return extending rearward from the strikeface to form at least a portion of at least one of the sole, the crown, the heel end, or the toe end; and wherein the front body is formed at a sub-solvus state at a temperature at least 200° C. below the solvus temperature of a front body material such that the front body material has a crystallographic orientation with no volume fraction than 30% for any one of a true pyramidal, true basal, or true prismatic grain orientation.

[0155] Clause 2. The golf club head of clause 1, wherein the front body material comprises: an adjacent solvus average grain size at an adjacent solvus state; a sub-solvus average grain size at the sub-solvus state; and a percent grain size reduction from the adjacent solvus average grain size to the sub-solvus average grain size between 55% to 70%.

[0156] Clause 3. The golf club head of clause 1, wherein the front body material comprises a longitudinal sample area comprising; a true basal orientation percentage above 60% of the total volume fraction at an adjacent solvus state; and a true basal orientation percentage below 30% of the total volume fraction at the sub-solvus state.

[0157] Clause 4. The golf club head of clause 1, wherein the front body can be oriented such that a longitudinal direction extends in a crown-to-sole direction.

[0158] Clause 5. The golf club head of clause 1, wherein the front body material comprises a transverse sample area comprising; a true pyramidal orientation percentage above 60% of the total volume fraction at an adjacent solvus state; and a true pyramidal orientation percentage below 30% of the total volume fraction at the sub-solvus state.

[0159] Clause 6. The golf club head of clause 1, wherein the front body can be oriented such that a transverse direction extends in a crown-to-sole direction.

[0160] Clause 7. The golf club head of clause 1, wherein the strikeface comprises a minimum thickness, measured in a direction perpendicular to a loft plane, between 0.075-0.118 inches.

[0161] Clause 8. The golf club head of clause 1, wherein the return comprises at least a portion of the sole having an impact response modulator monolithically formed with the front body.

[0162] Clause 9. The golf club head of clause 8, wherein the impact response modulator is positioned proximate to the strikeface.

[0163] Clause 10. The golf club head of clause 8, wherein the impact response modulator comprises a casing that forms one or more walls defining an aperture providing an opening though the sole, wherein the opening communicates between an interior cavity of the golf club head and an environment surrounding the golf club head.

[0164] Clause 11. The golf club head of clause 10, wherein the impact response modulator further comprises an insert positioned within the aperture and formed of a flexible, polymeric material.

[0165] Clause 12. The golf club head of clause 1, wherein the front body material is formed from 5325.

[0166] Clause 13. The golf club head of clause 12, wherein the sub-solvus average grain size at the sub-solvus state is between 2.55 micrometers to 3.10 micrometers.

[0167] Clause 14. The golf club head of clause 1, wherein the front body material is formed from 52AFS.

[0168] Clause 15. The golf club head of clause 14, wherein the sub-solvus average grain size at the sub-solvus state is between 4.00 micrometers to 4.75 micrometers.

[0169] Clause 16. A golf club head comprising: a crown, a sole opposite the crown, a toe end, a heel end opposite the toe end, and a rear end; a rear body; a front body formed of a front body material having a solvus temperature between 700° C. and 1050° C., comprising: a strikeface having a striking surface and a back surface opposite the striking surface; a return extending rearward from the strikeface to form at least portions of the crown and the sole; wherein the front body material is formed at a sub-solvus state at a temperature at least 200° C. below the solvus temperature of a front body material comprising: an adjacent solvus average grain size at an adjacent solvus state; a sub-solvus average grain size at the sub-solvus state; and a percent grain size reduction from the adjacent solvus average grain size to the sub-solvus average grain size between 55% to 70%; the front body material at the sub-solvus state has no volume fraction greater than 30% for any one of a true pyramidal, true basal, or true prismatic grain orientation.

[0170] Clause 17. The golf club head of clause 16, wherein the strikeface comprises a minimum thickness, measured in a direction perpendicular to a loft plane, between 0.075-0.118 inches.

[0171] Clause 18. The golf club head of clause 16, wherein the return comprises an impact response modulator monolithically formed with the front body.

[0172] Clause 19. The golf club head of clause 18, wherein the impact response modulator comprises a casing that forms one or more walls defining an aperture providing an opening though the sole, communicating between an interior cavity of the golf club head and an environment surrounding the golf club head.

[0173] Clause 20. The golf club of clause 1, wherein an orientation imaging map obtained from an EBSD scan of the front body material has no area fraction greater than 30% for any one of a true pyramidal, true basal, or true prismatic grain orientation.

[0174] Clause 21. A golf club head comprising: a crown, a sole opposite the crown, a toe end, a heel end opposite the toe end, and a rear end; a rear body; a front body formed of a front body material having a solvus temperature between 700° C. and 1050° C., comprising: a strikeface having a striking surface and a back surface opposite the striking surface; and a return extending rearward from the strikeface to form at least a portion of at least one of the sole, the crown, the heel end, or the toe end; and wherein the front body is formed at a sub-solvus state at a temperature at least 200° C. below the solvus temperature of a front body material such that the front body material has a crystallographic orientation wherein the front body material comprises a longitudinal sample area comprising; a true basal orientation percentage above 60% of the total volume fraction at an adjacent solvus state; and a true basal orientation percentage below 30% of the total volume fraction at the sub-solvus state.

[0175] Clause 22. The golf club head of clause 21, wherein the face body can be oriented such that the longitudinal direction extends in a crown-to-sole direction.

[0176] Clause 23. The golf club head of clause 21, wherein the strikeface comprises a minimum thickness, measured in a direction perpendicular to a loft plane, between 0.075-0.118 inches.

[0177] Clause 24. The golf club head of clause 21, wherein the return comprises an impact response modulator monolithically formed with the front body.

[0178] Clause 25. The golf club head of clause 24, wherein the impact response modulator is positioned proximately to the strikeface.

[0179] Clause 26. The golf club head of clause 24, wherein the impact response modulator comprises a casing that forms one or more walls defining an aperture providing an opening though the sole, communicating between an interior cavity of the golf club head and an environment surrounding the golf club head.

[0180] Clause 27. The golf club head of clause 26, wherein the impact response modulator further comprises an insert positioned within the aperture and formed of a flexible, polymeric material.

[0181] Clause 28. A golf club head comprising: a crown, a sole opposite the crown, a toe end, a heel end opposite the toe end, and a rear end; a rear body; a front body formed of a front body material having a solvus temperature between 700° C. and 1050° C., comprising: a strikeface having a striking surface and a back surface opposite the striking surface; and a return extending rearward from the strikeface to form at least a portion of at least one of the sole, the crown, the heel end, or the toe end; and wherein the front body is formed at a sub-solvus state at a temperature at least 200° C. below the solvus temperature of a front body material such that the front body material has a crystallographic orientation wherein the front body material comprises a transverse sample area comprising; a true pyramidal orientation percentage above 60% of the total volume fraction at an adjacent solvus state; and a true pyramidal orientation percentage below 30% of the total volume fraction at the sub-solvus state.

[0182] Clause 29. A golf club head comprising: a crown, a sole opposite the crown, a toe end, a heel end opposite the toe end, and a rear end; a rear body; a front body formed of a front body material having a solvus temperature between 700° C. and 1050° C., comprising: a strikeface having a striking surface and a back surface opposite the striking surface; and a return extending rearward from the strikeface to form at least a portion of at least one of the sole, the crown, the heel end, or the toe end; and wherein the front body is formed at a sub-solvus state at a temperature at least 200° C. below the solvus temperature of a front body material such that the front body material has a crystallographic orientation wherein the front body material comprises a longitudinal sample area comprising: a true basal orientation percentage between 50% and 60% of the total volume fraction at an adjacent solvus state; and a true basal orientation percentage between 20% and 30% of the total volume fraction at the sub-solvus state.

[0183] Clause 30. A golf club head comprising: a crown, a sole opposite the crown, a toe end, a heel end opposite the toe end, and a rear end; a rear body; a front body formed of a front body material having a solvus temperature between 700° C. and 1050° C., comprising: a strikeface having a striking surface and a back surface opposite the striking surface; and a return extending rearward from the strikeface to form at least a portion of at least one of the sole, the crown, the heel end, or the toe end; and wherein the front body is formed at a sub-solvus state at a temperature at least 200° C. below the solvus temperature of a front body material such that the front body material has a crystallographic orientation wherein the front body material comprises a transverse sample area comprising; a true pyramidal orientation percentage between 50% and 60% of the total volume fraction at an adjacent solvus state; and a true pyramidal orientation percentage between 20% and 30% of the total volume fraction at the sub-solvus state.

[0184] Clause 31. A golf club head comprising: a crown, a sole opposite the crown, a toe end, a heel end opposite the toe end, and a rear end; a rear body; a front body formed of a front body material having a solvus temperature between 700° C. and 1050° C., comprising: a strikeface having a striking surface and a back surface opposite the striking surface; and a return extending rearward from the strikeface to form at least a portion of at least one of the sole, the crown, the heel end, or the toe end; and wherein the front body is formed at a sub-solvus state at a temperature at least 200° C. below the solvus temperature of a front body material such that the front body material has a crystallographic orientation wherein the front body material comprises a longitudinal sample area comprising; wherein the front body material comprises: An adjacent solvus average grain size at an adjacent solvus state; a sub-solvus average grain size at the sub-solvus state; and a percent grain size reduction from the adjacent solvus average grain size to the sub-solvus average grain size between 55% to 70%; a true basal orientation percentage between 50% and 60% of the total volume fraction at an adjacent solvus state; and a true basal orientation percentage between 20% and 30% of the total volume fraction at the sub-solvus state.

[0185] Clause 32. A golf club head comprising: a crown, a sole opposite the crown, a toe end, a heel end opposite the toe end, and a rear end; a rear body; a front body formed of a front body material having a solvus temperature between 700° C. and 1050° C., comprising: a strikeface having a striking surface and a back surface opposite the striking surface; and a return extending rearward from the strikeface to form at least a portion of at least one of the sole, the crown, the heel end, or the toe end; and wherein the front body is formed at a sub-solvus state at a temperature at least 200° C. below the solvus temperature of a front body material such that the front body material has a crystallographic orientation wherein the front body material comprises a transverse sample area comprising; wherein the front body material comprises: An adjacent solvus average grain size at an adjacent solvus state; a sub-solvus average grain size at the sub-solvus state; and a percent grain size reduction from the adjacent solvus average grain size to the sub-solvus average grain size between 55% to 70%; a true pyramidal orientation percentage between 50% and 60% of the total volume fraction at an adjacent solvus state; and a true pyramidal orientation percentage between 20% and 30% of the total volume fraction at the sub-solvus state.

[0186] Replacement of one or more claimed elements constitutes reconstruction and not repair. Additionally, benefits, other advantages, and solutions to problems have been described with regard to specific embodiments. The benefits, advantages, solutions to problems, and any element or elements that may cause any benefit, advantage, or solution to occur or become more pronounced, however, are not to be construed as critical, required, or essential features or elements of any or all of the claims, unless such benefits, advantages, solutions, or elements are stated in such claim.

[0187] Moreover, embodiments and limitations disclosed herein are not dedicated to the public under the doctrine of dedication if the embodiments and / or limitations: (1) are not expressly claimed in the claims; and (2) are or are potentially equivalents of express elements and / or limitations in the claims under the doctrine of equivalents.

Examples

Embodiment Construction

[0086]The golf club heads described herein have a high strength titanium alloy strikeface with a more isotropic crystal structure and more isotropic mechanical properties than conventional strikefaces. The golf club heads have a front body, comprising a strikeface and a return formed of a near alpha alloy, an alpha-beta alloy, or a near beta alloy having a solvus temperature between 700° C. and 1050° C. Forming the front body at a temperature between 150° C. and 325° C. below the solvus temperature, using an increased tonnage to shape the front body, yields a crystalline structure with smaller grain size and reduced directionality compared to materials formed at solvus or adjacent solvus temperatures. Forming at such sub-solvus temperatures require fabrication techniques and equipment capable of applying a magnitude of tonnage not used before to form golf clubs. As the forming temperature is lowered further below the solvus of the metal, the amount of tonnage must be increased. Incr...

Claims

1. A golf club head comprising:a crown, a sole opposite the crown, a toe end, a heel end opposite the toe end, and a rear end;a rear body;a front body formed of a front body material having a solvus temperature between 700° C. and 1050° C., comprising:a strikeface having a striking surface and a back surface opposite the striking surface; anda return extending rearward from the strikeface to form at least a portion of at least one of the sole, the crown, the heel end, or the toe end; andwherein the front body is formed at a sub-solvus state at a temperature at least 200° C. below the solvus temperature of a front body material such that the front body material has a crystallographic orientation with no volume fraction than 30% for any one of a true pyramidal, true basal, or true prismatic grain orientation.

2. The golf club head of claim 1, wherein the front body material comprises:an adjacent solvus average grain size at an adjacent solvus state;a sub-solvus average grain size at the sub-solvus state; anda percent grain size reduction from the adjacent solvus average grain size to the sub-solvus average grain size between 55% to 70%.

3. The golf club head of claim 1, wherein the front body material comprises a longitudinal sample area comprising;a true basal orientation percentage above 60% of the total volume fraction at an adjacent solvus state; anda true basal orientation percentage below 30% of the total volume fraction at the sub-solvus state.

4. The golf club head of claim 1, wherein the front body can be oriented such that a longitudinal direction extends in a crown-to-sole direction.

5. The golf club head of claim 1, wherein the front body material comprises a transverse sample area comprising;a true pyramidal orientation percentage above 60% of the total volume fraction at an adjacent solvus state; anda true pyramidal orientation percentage below 30% of the total volume fraction at the sub-solvus state.

6. The golf club head of claim 1, wherein the front body can be oriented such that a transverse direction extends in a crown-to-sole direction.

7. The golf club head of claim 1, wherein the strikeface comprises a minimum thickness, measured in a direction perpendicular to a loft plane, between 0.075-0.118 inches.

8. The golf club head of claim 1, wherein the return comprises at least a portion of the sole having an impact response modulator monolithically formed with the front body.

9. The golf club head of claim 8, wherein the impact response modulator is positioned proximate to the strikeface.

10. The golf club head of claim 8, wherein the impact response modulator comprises a casing that forms one or more walls defining an aperture providing an opening though the sole, wherein the opening communicates between an interior cavity of the golf club head and an environment surrounding the golf club head.

11. The golf club head of claim 10, wherein the impact response modulator further comprises an insert positioned within the aperture and formed of a flexible, polymeric material.

12. The golf club head of claim 1, wherein the front body material is formed from 5325.

13. The golf club head of claim 12, wherein a sub-solvus average grain size at the sub-solvus state is between 2.55 micrometers to 3.10 micrometers.

14. The golf club head of claim 1, wherein the front body material is formed from 52AFS.

15. The golf club head of claim 14, wherein a sub-solvus average grain size at the sub-solvus state is between 4.00 micrometers to 4.75 micrometers.

16. A golf club head comprising:a crown, a sole opposite the crown, a toe end, a heel end opposite the toe end, and a rear end;a rear body;a front body formed of a front body material having a solvus temperature between 700° C. and 1050° C., comprising:a strikeface having a striking surface and a back surface opposite the striking surface;a return extending rearward from the strikeface to form at least portions of the crown and the sole;wherein the front body material is formed at a sub-solvus state at a temperature at least 200° C. below the solvus temperature of a front body material comprising:an adjacent solvus average grain size at an adjacent solvus state;a sub-solvus average grain size at the sub-solvus state; anda percent grain size reduction from the adjacent solvus average grain size to the sub-solvus average grain size between 55% to 70%;the front body material at the sub-solvus state has no volume fraction greater than 30% for any one of a true pyramidal, true basal, or true prismatic grain orientation.

17. The golf club head of claim 16, wherein the strikeface comprises a minimum thickness, measured in a direction perpendicular to a loft plane, between 0.075-0.118 inches.

18. The golf club head of claim 16, wherein the return comprises an impact response modulator monolithically formed with the front body.

19. The golf club head of claim 18, wherein the impact response modulator comprises a casing that forms one or more walls defining an aperture providing an opening though the sole, communicating between an interior cavity of the golf club head and an environment surrounding the golf club head.

20. The golf club of claim 1, wherein an orientation imaging map obtained from an EBSD scan of the front body material has no area fraction greater than 30% for any one of a true pyramidal, true basal, or true prismatic grain orientation.

Images