Golf club head with textured striking face and method of manufacturing same

Abstract

Described herein are embodiments of a golf club head having a textured striking face and a method of forming the club head through laser shock processing. The golf club head may include a body and a striking face. The striking face has a textured front surface with an array of recesses. Each recess is 0.01 μm in diameter. 2 (1×10 -8 mm 2 ) to 250,000 μm 2 (0.25mm 2 ) The textured front surface can affect the spin imparted to the golf ball upon impact. Other embodiments may be described and claimed.

Description

[Technical Field]

[0001] (cross reference) This application claims priority to U.S. Provisional Patent Application No. 62 / 948,083, filed December 13, 2019, U.S. Provisional Patent Application No. 62 / 976,987, filed February 14, 2020, and U.S. Provisional Patent Application No. 63 / 198,112, filed September 29, 2020, the entire contents of all of which are incorporated herein by reference.

[0002] The present disclosure relates generally to golf equipment, and more particularly to golf club heads having textured striking faces. The surface texture or coefficient of friction of the striking face can affect the characteristic time of the golf club head and the spin imparted to a golf ball upon impact. Certain surface textures can also increase the fatigue and wear resistance of the golf club head. [Background technology]

[0003] Laser shock peening (LSP) is a process that creates an array of laser-shocked impact zones. In the golf industry, this technique has only been used to treat striking faces to increase their hardness. Laser shock peening of a striking face creates forged indentations (or depressions) in the front surface of the striking face. During laser shock processing, the laser passes through a containment layer and enters an absorbing layer above the striking face being processed. Energy from the laser beam is absorbed by the absorbing layer, rapidly transforming it into plasma. The rapid generation of plasma creates a hammer-like shock wave that deforms the front surface of the striking face, creating depressions in the surface. The amount of laser light affects the amount of plasma generated. The amount of plasma, in turn, affects the strength of the shock wave, which corresponds to the depth of the depressions (or crater depth).

[0004] Laser shock peening (LSP) has been used to introduce residual compressive stresses into certain portions of the striking face, creating a stress gradient between the treated and untreated portions of the striking face. Each laser pulse is 4 mm in diameter, corresponding to the size of the laser beam. 2 The technique treats areas larger than 4mm 2 However, previous techniques have only been able to treat striking face areas of sizes greater than 4 mm, and have not been able to sufficiently alter the coefficient of friction between the striking face and the golf ball. The prior art has been able to treat striking face areas of sizes greater than 4 mm, and have not been able to sufficiently alter the coefficient of friction between the striking face and the golf ball. 2 There is a need for a striking face having smaller depressions (or indentations) than the conventional striking face. There is also a need in the art for a striking face having improved durability, fatigue resistance, and crack propagation. [Brief explanation of the drawings]

[0005] [Figure 1] FIG. 1 shows a view perpendicular to the face of a wedge-type golf club head having a textured striking face, including a close-up illustration of the location of the texture interspersed between grooves, according to one embodiment.

[0006] [Figure 2] 1 illustrates a face-normal view of a wedge-type golf club head having a fully textured striking face front surface according to one embodiment.

[0007] [Figure 3] 1 illustrates a face-normal view of a wedge-type golf club head having a striking face with a textured region on the front surface of the striking face according to one embodiment.

[0008] [Figure 4] 1 shows a perspective view of an array of square recesses according to one embodiment.

[0009] [Figure 5] 1 shows a perspective view of an array of hexagonal recesses according to one embodiment.

[0010] [Figure 6] 4 shows a view normal to the surface of the array of square recesses of FIG. 3.

[0011] [Figure 7] 5 shows a view normal to the surface of the array of hexagonal recesses of FIG. 4.

[0012] [Figure 8A] 6 shows a cross-sectional view of the array of square recesses of FIG. 3 taken along line VI-VI of FIG. 6 according to a first embodiment.

[0013] [Figure 8B] 8B shows a cross-sectional view of the array of square recesses of FIG. 3 taken along line VI-VI of FIG. 6 according to a second embodiment having deeper recesses than the first embodiment of FIG. 8A.

[0014] [Figure 9] 1 shows depth graphs of four example surface profiles (a), (b), (c), and (d) formed by shock waves from different laser doses.

[0015] [Figure 10] 1 illustrates how the face of a wedge can be treated using a laser shock surface patterning (LSSP) process.

[0016] [Figure 11] 1 illustrates a top view of a production apparatus with a base plate and frame, according to one embodiment.

[0017] [Figure 12] 11 shows a top view of the production apparatus of FIG. 10 without the frame.

[0018] [Figure 13]1 shows a graph of launch angles for control and example club heads under wet and dry conditions according to testing.

[0019] [Figure 14] 1 shows a graph of spin rates for control and example club heads according to tests conducted under both wet and dry conditions.

[0020] [Figure 15] 1 shows a graph of ball speed for control club heads and example club heads according to tests conducted under both wet and dry conditions.

[0021] [Figure 15] 1 shows a graph of the statistical area for control club heads and example club heads according to tests conducted under both wet and dry conditions. DETAILED DESCRIPTION OF THE INVENTION

[0022] All printed publications cited herein are incorporated by reference in their entirety, except where any definition, subject matter is disclaimed or disclaimed, and where the incorporated material is inconsistent with the explicit disclosure herein, in which case the language of this disclosure will control.

[0023] The invention described herein is a golf club head having a textured surface with a plurality of recesses. The textured surface can be a body surface, such as a front striking face surface, a rear striking face surface, or a sole surface. In some embodiments, multiple surfaces are textured. The front striking face surface, the rear striking face surface, and / or the sole surface can be textured through a laser shock surface patterning (LSSP) treatment or texturing process, which is similar to, but distinct from, a laser shock peening (LSP) process. The LSSP process differs from existing LSP processes because it results in a higher coefficient of friction between the treated surface and a golf ball. The laser shock surface patterning process can be used to create a golf club head with a textured surface having a plurality of recesses (i.e., 4,000,000 μm² (4 mm²)) created using a previous LSP process. 2 ) or larger occupied area) to create a forged recess that is significantly smaller (i.e., 0.01 μm 2 (1×10 -8 mm 2 ) to 250,000 μm 2 (0.25mm 2 ) occupation area). The laser shock surface patterning (LSSP) process described herein also creates clearly defined boundaries for the forging indentations (or depressions). The textured surfaces described herein can have a higher coefficient of friction than surfaces lacking the LSSP texture. For embodiments having a textured striking face front surface, the multiple recesses can improve shot performance, particularly in wet conditions. In particular, texturing the striking face using the LSSP process can reduce launch angle, increase ball spin, and maintain ball speed.

[0024] The recesses created using LSSP have clearly defined boundaries that control the resulting coefficient of friction between the striking face and the golf ball. For low-loft club heads, the increased coefficient of friction can improve the spin rate and ball flight trajectory, such as launch angle, of an impacted golf ball, especially in wet conditions. Treating at least one surface of the striking face using LSSP can create a finer grain structure and introduce compressive residual stresses, improving fatigue resistance, durability, and energy storage mechanics. The LSSP process described herein can also be used to relieve stresses in the weld zone, creating a more aerodynamic surface. definition

[0025] The golf club heads described herein may have a loft angle, measured as the angle between the contact surface and a plane tangent to the center point of the striking face. Generally, driver-type club heads have lower loft angles than iron-type or wedge-type club heads.

[0026] "Low lofted" as used herein may refer to golf club heads having a loft angle of less than 18 degrees. "High lofted" as used herein may refer to golf club heads having a loft angle of 18 degrees or greater. However, the 18 degree cutoff value can be shifted by up to plus or minus 4 degrees for some designs based on the desired performance goals of the particular golf club head.

[0027] "Laser shock peening," or "LSP" for short, as used herein, is a process of treating a surface by forging a depression equal to the spot size of the laser beam used during the process. The laser beam spot size (and the resulting depression occupation size) is 4 mm. 2 More than 5mm 2That's it. The LSP process can include placing an absorbing layer over the surface being treated, placing a confinement layer over the absorbing layer, and irradiating a laser through the confinement layer to convert the absorbing layer into a plasma. The creation of the plasma produces shock waves that deform or forge the surface below the absorbing layer, creating a depression that matches the spot size of the laser beam.

[0028] "Laser shock surface patterning," or "LSSP" for short, as used herein, refers to the process of applying a 0.01 μm laser shock to a surface to impart texture to it. 2 (1×10 -8 mm 2 ) to 250,000 μm 2 (0.25mm 2 LSSP is a process for treating a surface by forging at least one plurality of depressions (a plurality of depressions), each having an area between the apertures (the "apertures") of the mask layer and the surface. In other words, each depression has an area significantly smaller than the spot size of the laser beam used during the LSSP process. The LSSP process uses a mask layer (also called a mesh) to block the laser beam from affecting certain areas of the surface being treated. In this manner, the mask layer allows many tiny depressions to be created with each single laser shock. The LSSP process may include placing a mask layer (mesh) over the surface being treated, placing an absorbing layer over the mask layer, placing a confining layer over the absorbing layer, and irradiating a laser through the confining layer to convert the absorbing layer into plasma. The creation of the plasma causes shock waves moving through apertures in the mask layer to deform or forge the surface below the apertures, creating depressions that match the size of the apertures in the mask layer. Portions of the surface covered by the material of the mask (mesh) are protected from the shock waves and therefore remain unforged.

[0029] As used herein, "golf ball" refers to a urethane-coated golf ball. The coefficients of friction set forth below were measured between a metal striking face and a urethane-coated golf ball.

[0030] As used herein, a "treated surface" can be understood to include the treated surface layer and adjacent material layers affected during surface treatment. In other words, a "treated surface" can refer to any material that exhibits an altered grain structure after the LSSP process. When used in the context of discussing coefficient of friction, a "treated surface" can refer to only the exposed surface layer. In these cases, the "treated surface" can have a measurable coefficient of friction relative to an external object, such as a golf ball.

[0031] "Launch angle" as used herein refers to the angle between the contact patch and the average trajectory of the golf ball at or immediately after impact between the golf ball and the golf club head.

[0032] As used herein, "dry conditions" may refer to conditions in which the striking face has no visible moisture on its front surface. "Dry conditions" may also refer to weather conditions in which there is no rain, dew, condensation, or other forms of moisture that interfere with contact between the golf ball and the striking face of the golf club head.

[0033] "Wet conditions," as used herein, may refer to conditions in which the striking face has visible moisture on its front surface. "Wet conditions," as used herein, may also refer to weather conditions including rain, dew, condensation, or other forms of moisture that interfere with contact between the golf ball and the striking face of the golf club head. Hitting a shot from tall grass also constitutes wet conditions.

[0034] As used herein, a "flat" or "planar" surface may refer to a surface having an Ra value of about 1 μm (1000 nm) or less. In some embodiments, a "flat" or "planar" surface may have an Ra value of less than 0.02 μm (20 nm).

[0035] The textured striking face surface and / or textured body surface described herein comprises an array of forged recesses (or depressions), each of which has a surface footprint and a maximum depth. The footprint of each recess is less than 0.01 μm. 2 to 250,000 μm 2 The depth of each forged depression ranges between 0.1 μm and 15 μm. In addition to modifying the surface texture, the laser shock surface patterning (LSSP) process also compacts the material grain structure of the treated surface. Depressed texturing controls the coefficient of friction of the treated surface relative to the golf ball surface. When the striking face is the treated surface, the coefficient of friction increases, which can improve shot performance by lowering launch angle, increasing ball spin, and maintaining ball speed. Depressed texturing can also control the residual stresses (related to the compacted / forged configuration of the material) and aerodynamic properties of the treated surface. Additional benefits of recessed texturing may include, but are not limited to, slowing crack propagation, reducing material fatigue, and / or increasing energy storage during impact.

[0036] The golf club head 10 described herein may include a body 24 and a striking face 12. The body 24 defines a front portion, a rear portion opposite the front portion, a top rail 30, a sole 36 opposite the top rail 30, a sole leading edge 40 at the junction of the striking face 12 and the sole 36, a toe end 42, a heel end 44 opposite the toe end 42, and a hosel 46 connected to the heel end 44. When the golf club is in the address position, the top rail 30 forms the top of the club head 10 and the sole 36 forms the bottom of the club head 10. The striking face 12 has a geometric center 14. The striking face 12 forms a striking surface for impacting a golf ball. In some embodiments, the striking face 12 is formed by a face plate that fits within a recess in the front of the body 24.

[0037] The striking face 12 may have a front surface 16 and a rear surface (not illustrated) opposite the front surface 16. The sole 36 may have a sole surface. At least a portion of the sole surface may be configured to engage the turf or ground when a golfer uses the golf club. The top rail 30 may have a top rail surface. The golf club head may be a driver-type, fairway wood-type, hybrid-type, or iron-type golf club head. The driver-type, fairway wood-type, and hybrid-type club heads may have a crown rather than a top rail.

[0038] The golf club head 10 may be textured with one or more recess arrays 50 extending across one or more of the striking face front surface 16, the striking face rear surface, and / or the sole surface. Any recess array 50 may also be referred to as a plurality of recesses, a textured array, a surface texture, and / or a geometric friction shape. The textures on the striking face front surface 16, the striking face rear surface, and / or the sole surface may be formed using a laser impact surface patterning (LSSP) process. As described below, the striking face rear surface and / or the sole surface may be textured similarly to the striking face front surface 16. In some embodiments, only the striking face front surface 16 is textured with the recess array 50. In some embodiments, only the striking face rear surface is textured with the recess array 50. In some embodiments, only the sole surface is textured with the recess array 50.

[0039] In other embodiments, the striking face front surface 16 may include one or more plurality of recesses 50. For example, the striking face front surface 16 may be textured with a first plurality of recesses 50 (first array), and the striking face rear surface may be textured with a second plurality of recesses (second array). In yet other embodiments, the striking face front surface 16 may be textured with a first plurality of recesses 50 (first array), and the sole surface may be textured with a second plurality of recesses (second array). Alternatively, the striking face front surface 16 may be textured with a first plurality of recesses 50 (first array), the striking face rear surface may be textured with a second plurality of recesses (second array), and the sole surface may be textured with a third plurality of recesses (third array). In some embodiments, a single textured surface may comprise multiple recess arrays 50.

[0040] The golf club head can be formed from a metallic material. In some embodiments, the striking face 12 can be formed from a different metal than the remainder of the club head 10. Examples of metals can include, but are not limited to, steel, alloy steel, stainless steel, stainless steel alloy, C300, C350, Ni (nickel)-Co (cobalt)-Cr (chromium)-alloy steel, 8620 alloy steel, S25C steel, 303SS, 17-4SS, carbon steel, maraging steel, 565 steel, AISI type 304 or AISI type 630 stainless steel, titanium alloy, Ti-6-4, Ti-3-8-6-4-4, Ti-10-2-3, Ti15-3-3-3, Ti15-5-3, Ti185, Ti6-6-2, Ti-7s, Ti-9s, Ti-92, or Ti-8-1-1 titanium alloy, amorphous alloy, or other similar metal. The material of the golf club head can affect the amount of laser light required to achieve certain recess parameters, such as the maximum recess depth described below. Striking face front surface texturing

[0041] 2-5, the striking face front surface 16 includes a textured region 48. The textured region 48 can have a surface roughness that is different from the surface roughness of the remainder of the striking face front surface 16. The different surface roughness of the textured region 48 can be achieved by applying a laser shock surface patterning (LSSP) process to the textured region 48 to create a plurality of depressions 50. The textured region 48 can cover between 20% and 100% of the striking face front surface 16. In the embodiment of FIG. 2, the textured region 48 covers the entire front surface 16 (approximately 100% of the front surface 16). In some embodiments, the textured region 48 can cover between 20% and 30%, between 30% and 40%, 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% of the front surface 16. In some embodiments, the textured region 48 covers 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100% of the front surface 16.

[0042] In some embodiments, such as the embodiment of FIG. 3 , the textured region 48 may be located only in a portion of the striking face 12 that also includes conventional grooves 130. In other embodiments, the majority of the textured region 48 may be located in the low region 20 of the striking face 12. The low region 20 may be any portion of the striking face 12 below a horizontal reference axis 72 extending through the geometric center 14 of the striking face. In other embodiments, the majority of the textured region 48 may be located in the high region 22 of the striking face 12. The high region 22 may be any portion of the striking face 12 above the horizontal reference axis 72. In some embodiments, the textured region 48 may have a height 58, measured from the sole 36 to the top rail 30, of greater than 0.2 inches, greater than 0.4 inches, greater than 0.6 inches, greater than 0.8 inches, greater than 1.0 inches, greater than 1.2 inches, greater than 1.4 inches, greater than 1.6 inches, greater than 1.8 inches, or greater than 2 inches. Locating the textured areas 48 primarily within the low or high regions 20, 22 of the striking face 12 can modify the spin imparted to a golf ball on low or high hits, respectively. In some embodiments, the striking face front surface 16 can be selectively textured in certain areas to produce a striking face 12 that responds with approximately the same spin regardless of where the golf ball impacts the striking face 12. Selective texturing of one or more portions of the striking face front surface 16 can also modify the residual (internal) stresses in the striking face, changing the striking face's durability, deformation characteristics, and energy storage mechanics.

[0043] As illustrated in the close-up perspective views of FIGS. 4 and 5 , the textured region 48 includes a plurality of recesses 50 that provide texture to the front surface 16. The recesses 50 may also be referred to as a recess array. The recesses 50 may be positioned in a pattern throughout the textured region 48 and throughout at least a portion of the striking face front surface 16. The recesses 50 may cover between 20% and 100% of the striking face front surface 16, as may the coverage of the textured region 50. In some embodiments, the recesses 50 may cover 20%-30%, 30%-40%, 40%-50%, 50%-60%, 60%-70%, 70%-80%, 80%-90%, or 90%-100% of the front surface 16. In some embodiments, the plurality of recesses 50 can cover 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100% of the front surface.

[0044] 2, 4, and 5, the plurality of recesses 50 (recess array) may include a plurality of individual recesses 100 (also referred to as "dimples"). The plurality of recesses 50 may be arranged in any pattern and oriented in any direction throughout the club head. The layout of the plurality of recesses 50 may vary between embodiments. In some embodiments, the plurality of recesses 50 may be arranged in a row pattern. The plurality of recesses 50 may also be arranged in columns. The rows of recesses may be linearly oriented. The recess array orientation may be defined as a direction parallel to the linear orientation of the rows. The recess array orientation may be represented by an array axis 70. In some embodiments, the plurality of recesses 50 (recess array) may be horizontally oriented. Referring to FIG. 2, a horizontal reference axis 72 is shown extending from the heel end 44 to the toe end 42 of the club head 10 through the geometric center 14 of the striking face 12. The array axis 70 (representing the recessed array orientation) can be offset by an angle of plus or minus 0 to 90 degrees from the horizontal reference axis 72. In some embodiments, the array axis 70 is offset from the horizontal reference axis 72 by + / - 10 degrees, + / - 20 degrees, + / - 30 degrees, + / - 40 degrees, + / - 45 degrees, + / - 50 degrees, + / - 60 degrees, + / - 70 degrees, + / - 80 degrees, or + / - 90 degrees.

[0045] In some embodiments, the rows of recesses can be arcuate or curved. The rows of recesses can be concave relative to the sole 36, concave relative to the top rail 30, concave relative to the heel end 44, concave relative to the toe end 42, concave relative to the upper toe end, concave relative to the upper heel end, concave relative to the lower toe end, or concave relative to the lower heel end of the club head. In some embodiments, the recesses can extend radially from the geometric center 14 of the striking face 12. The recesses can form circular rows with increasing diameters about the geometric center 14 of the striking face. Alternatively, the recesses can form oval, elliptical, rectangular / oval, square, rectangular, triangular, or any other suitably shaped rows about the geometric center 14 of the striking face 12. In some embodiments, the plurality of recesses are centered about a point that is offset from the geometric center 14 of the striking face 12 .

[0046] Multiple depressions 50 cm 2 Dimple density of approximately 3,040 to 75,950 dimples per square inch (in 2 In some embodiments, the recess density is about 19,600 to 490,000 recesses per cm. 2 There may be about 3,000 to 5,000, 5,000 to 10,000, 10,000 to 30,000, 30,000 to 60,000, or 45,000 to 75,950 recesses per cavity.

[0047] Referring to FIG. 3 , in some embodiments, the texturing region 48 can include a plurality of pocket regions 62 (also referred to as laser spot regions / areas or laser coverage regions / areas). Each pocket region 62 can correspond to the spot size of the laser beam used during the LSSP process. However, the LSSP process uses a mask layer (mesh) to protect portions of the surface during processing. Therefore, each pocket region 62 has a portion that is masked (protected) surface area and a portion that is exposed (unprotected) surface area. The exposed surface area becomes a plurality of recesses 50. The creation of the plurality of recesses 50 occurs because portions of the pocket region 62 are exposed to plasma shock waves through apertures in the mask layer during LSSP. Due to the mask layer (mesh), each pocket region 62 can include a plurality of recesses 50. The pocket regions 62 can be circular, square, hexagonal, triangular, or any other suitable shape. The pocket regions 62 can be arranged in a pattern or array across the texturing region 48. The pocket regions 62 may be located immediately adjacent to one another to form rows. The rows of pocket regions 62 may be positioned between the grooves 130 to provide texture to the areas of the front surface 16 between the grooves 130.

[0048] In some embodiments, the pocket regions 62 correspond to the spot size of the laser beam used during the LSSP process. For circular pocket regions, each pocket region 62 may have a spot size (diameter) of 1 mm to 5 mm. In some embodiments, the spot size may be 1 mm to 3 mm, 1.5 mm to 3.5 mm, 2 mm to 4 mm, 2.5 mm to 4.5 mm, or 3 mm to 5 mm. For example, the spot size may be 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, or 5 mm. In some embodiments, the pocket regions 62 may be separated from other pocket regions 62 by less than about 0.1 mm (100 μm).

[0049] Each pocket region 62 may include 10 to 15,500 recesses. In some embodiments, each pocket region 62 may include 10 to 100, 100 to 500, 500 to 1000, 1000 to 5000, 5000 to 10,000, 10,000 to 15,500 recesses, or any intermediate range of recesses. For example, in a circular pocket region 62 having a diameter of 1 mm, each pocket region 62 may include approximately 10 to 610 recesses. For example, in a circular pocket region 62 having a diameter of 5 mm, each pocket region 62 may include approximately 500 to 15,500 recesses. The plurality of recesses 50 within the pocket region 62 provides roughness to the textured region 48, varying the coefficient of friction between the textured region 48 and a golf ball.

[0050] 4-6 , each recess 100 of the plurality of recesses 50 has an occupying shape as seen when viewed orthogonally from the striking face front surface 16. The occupying shape may be a parallelogram, rectangle, square, diamond (or rhombus), circle, triangle, pentagon, hexagon, or any other suitable shape. In some embodiments, the occupying shape may have one continuous side, two arcuate sides, three sides, four sides, five sides, six sides, seven sides, eight sides, nine sides, or ten sides. Each recess 100 includes sidewalls 106 that extend into the front surface 16 to form the recess 100. The recess sidewalls 106 correspond to the sides of the occupying shape in a plane coincident with the front surface 16. In some embodiments, the plurality of recesses 50 may include recesses having different occupying shapes on the same striking face. In some embodiments, one section of the striking face 12 may have a first array of recess shapes, and another section of the striking face 12 may have a second array of recess shapes. For example, the first recess shapes may be hexagonal and the second recess shapes may be square. In some embodiments, a single array of recesses may have any combination of multiple occupying shapes. For example, a single array may have hexagonal and triangular shapes. As a further example, a single array may have hexagonal, square, and triangular shapes. As a further example, a single array may have circular and square shapes. As a further example, a single array may have rectangular and square shapes.

[0051] 6 and 8, the occupied features can be surrounded by a surface footprint 102. In other words, the occupied area 102 is the area surrounded by recess sidewalls 106 in a plane coincident with the front surface 16. The occupied area 102 of each recess can be 0.01 μm 2 to 250,000 μm 2 In some embodiments, the occupied area 102 of each recess can be 0.01 μm 2 to 0.10 μm 2 , 0.10 μm 2 to 0.20 μm 2 , 0.20 μm 2 to 0.30 μm2 , 0.30 μm 2 to 0.40 μm 2 , 0.40 μm 2 to 0.50 μm 2 , 0.50 μm 2 to 1.0 μm 2 , 1.0 μm 2 to 10 μm 2 , 10 μm 2 to 50 μm 2 , 50 μm 2 to 100 μm 2 , 100 μm 2 to 200 μm 2 , 200 μm 2 to 300 μm 2 , 300 μm 2 to 400 μm 2 , 400 μm 2 to 500 μm 2 , 500 μm 2 to 600 μm 2 , 600 μm 2 to 700 μm 2 , 700 μm 2 to 800 μm 2 , 800 μm 2 to 900 μm 2 , 900 μm 2 to 1000 μm 2 , 1000 μm 2 to 3000 μm 2 , 3000 μm 2 to 6000 μm 2 , 6000 μm 2 to 9000 μm 2 , 9000 μm 2 to 12,000 μm 2 , 12,000 μm 2 to 15,000 μm 2 , 15,000 μm 2 to 30,000 μm 2 , 30,000 μm 2 to 60,000 μm 2 , 60,000 μm 2 to 100,000 μm 2 , 100,000 μm 2 to 150,000 μm 2, 150,000 μm 2 to 200,000 μm 2 , or 200,000 μm 2 to 250,000 μm 2 The small surface footprint 102 also allows portions of the striking face 12 to be selectively treated without affecting the remainder of the striking face 12.

[0052] 4-8 , each recess 100 of the plurality of recesses 50 on the striking face front surface 16 may have a bottom surface 126 and a sidewall 106 (also called a side or edge). Some recesses 100 may have a first sidewall 108, a second sidewall 110 opposite the first sidewall 108, an upper sidewall 112, and a lower sidewall 114. The sidewall 106 may have a sharper and more defined geometric shape compared to sidewalls formed by a conventional LSP process. Referring to FIGS. 8A and 8B , the sidewall 106 connects to the striking face front surface 16 approximately perpendicularly. The corner-like intersection between the sidewall 106 and the striking face front surface 16 may be slightly rounded.

[0053] The amount of curvature at the intersection between the sidewall 106 and the front surface 16 can be characterized by the radius of curvature 116 of a reference circle along the cross-sectional profile of the intersection. The radius of curvature of the intersection can also be referred to as the exit radius. The radius of curvature 116 of the reference circle can be between one-tenth and one-hundredth of the radius of curvature of the intersection of the recess formed by the LSP process. In some embodiments, the radius of curvature 116 can be one-tenth, one-twentieth, one-thirtieth, one-fortieth, one-fiftieth, one-sixtieth, one-seventieth, one-eighth, one-ninth, or one-hundredth of the radius of curvature of the intersection (exit geometry) of the recess formed by the LSP process. During the LSP process, each laser beam impact forms a single recess without masking to block any portion of the laser beam. The edge of the laser beam imparts a gentle forging action across the entire surface area that will become the intersection or exit geometry of the recess. In other words, the LSP process creates recesses with sloped exit geometries rather than sharp exit geometries. Using the same laser light dose, the LSP process creates large, rounded recesses, whereas the LSSP process creates small, sharp recesses.

[0054] Media blasting is also used in the golf industry to texture surfaces. Media blasting relies on high-velocity solid matter impacts on the workpiece surface to modify the surface morphology. Each solid particle can travel at an unknown speed and in an unknown direction, resulting in overlapping impacts that flatten the surface. Peaks (any feature higher than the surface's starting elevation) and valleys (any feature lower than the surface's starting elevation) can grow together, resulting in an undulating surface with sharp peaks. However, repeated solid matter impacts on the same surface area and the size of the particles themselves result in shallow valleys. Therefore, media blasting cannot produce both sharp edges and deep recesses for increased friction. In contrast, the LSSP process can produce deep and sharp recesses (small radii of curvature at intersections or exit edges).

[0055] Another form of surface texturing used in the golf industry is laser etching. Laser etching removes material from a surface by ablating it into vapor. The treated surface transitions from solid to liquid to gas to liquid and back to solid. The metal hardens as it resolidifies. The morphology of a laser-etched surface comprises shallow valleys and rounded peaks. The LSSP process can produce deep and sharp depressions by using a mask layer (mesh) to guide and control shock waves to create micro-features, referred to herein as depressions 100. Neither the LSP process, media blasting, nor laser etching allows for independent control of depression parameters such as location, spacing (separation distance), and edge sharpness (intersection radius).

[0056] The sidewalls 106 may connect approximately perpendicularly to the recessed bottom surface 126 in a manner similar to how they connect to the striking face front surface 16. In other words, the sidewalls 106 may form a sharp radius of curvature with the recessed bottom surface 126.

[0057] 6-8, in some embodiments, each recess 100 includes a width 120 measured in a direction parallel to the array axis 70 of the recess array 50. In embodiments having a horizontal recess array, the width 120 is measured in a direction from the heel end 44 toward the toe end 42 (heel-toe direction). In some embodiments, the width 120 can span from the first sidewall 108 to the second sidewall 110 of the recess 100. The width 120 is measured through the center point 104 of the recess. For example, the width of a circular recess will be equal to the diameter of the circular recess. The recess width 120 can range from 0.1 μm to 500 μm (approximately 3.9×10 -6inches to approximately 0.0197 inches). In some embodiments, the width 120 of the recesses can be in the range of 0.1 μm to 0.5 μm, 0.5 μm to 1 μm, 1 μm to 5 μm, 5 μm to 10 μm, 10 μm to 20 μm, 20 μm to 30 μm, 30 μm to 40 μm, 40 μm to 50 μm, 50 μm to 60 μm, 60 μm to 70 μm, 70 μm to 80 μm, 80 μm to 90 μm, 90 μm to 100 μm, 100 μm to 150 μm, 150 μm to 200 μm, 200 μm to 250 μm, 250 μm to 300 μm, 300 μm to 350 μm, 350 μm to 400 μm, 400 μm to 450 μm, or 450 μm to 500 μm. In some embodiments, the width of the recesses is 0.1 μm, 0.5 μm, 1 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, 210 μm, 220 μm, 230 μm, 7, each recess 100 can include a lateral width 118 (also referred to as a sidewall length) that is less than the width 120 measured through the center 104 of the recess 100.

[0058] 6 and 7 , in some embodiments, each recess 100 has a height 122 measured in a direction perpendicular to the array axis 70 of the recess array 50. In some embodiments, the width 122 extends between the upper sidewall 112 and the lower sidewall 114. For a horizontally oriented recess array 50, the recess height 122 may be measured along the striking face front surface 16 in a direction from the sole leading edge 40 toward the top rail 30 of the club head. The recess height 122 may be the same as the recess width 120 for some recesses 100.

[0059] The height of the recess 122 ranges from 0.1 μm to 500 μm (approximately 3.9 × 10 -6 inch to about 0.0197 inches). In some embodiments, the height 122 of the recesses can be in the range of 0.1 mmμm to 0.5 μm, 0.5 μm to 1 μm, 1 μm to 5 μm, 5 μm to 10 μm, 10 μm to 20 μm, 20 μm to 30 μm, 30 μm to 40 μm, 40 μm to 50 μm, 50 μm to 60 μm, 60 μm to 70 μm, 70 μm to 80 μm, 80 μm to 90 μm, 90 μm to 100 μm, 100 μm to 150 μm, 150 μm to 200 μm, 200 μm to 250 μm, 250 μm to 300 μm, 300 μm to 350 μm, 350 μm to 400 μm, 400 μm to 450 μm, 450 μm to 500 μm. In some embodiments, the height of the recesses is 0.1 μm, 0.5 μm, 1 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, 210 μm, 220 μm, 230 μm , 240 μm, 250 μm, 260 μm, 270 μm, 280 μm, 290 μm, 300 μm, 310 μm, 320 μm, 330 μm, 340 μm, 350 μm, 360 μm, 370 μm, 380 μm, 390 μm, 400 μm, 410 μm, 420 μm, 430 μm, 440 μm, 450 μm, 460 μm, 470 μm, 480 μm, 490 μm, 500 μm.

[0060] 8A and 8B, each recess 100 includes a maximum depth 124. The embodiment of FIG. 8B has deeper recesses and a greater maximum depth 124 than the embodiment of FIG. 8A. The maximum depth 124 of the recess may be measured perpendicular to the front striking face surface 16. In other words, the maximum depth 124 of the recess may be measured from a plane coincident with the front striking face surface 16 to a bottom surface 126 of the recess. The maximum depth 124 of each recess may range from 0.1 μm to 15 μm. In some embodiments, the maximum depth 124 of the recesses can be in the range of 0.1 μm to 0.5 μm, 0.5 μm to 0.9 μm, 0.8 μm to 1.2 μm, 1.0 μm to 3.0 μm, 3.0 μm to 5.0 μm, 5.0 μm to 7.0 μm, 7.0 μm to 9.0 μm, 9.0 μm to 11 μm, 11 μm to 13 μm, 13 μm to 15 μm. In some embodiments, the maximum depth of the recesses can be 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, or 15 μm. The depth 124 of each recess 100 affects the coefficient of friction of the striking face front surface 16.

[0061] When the recesses 100 are formed by laser shock processing (LSSP), the depth 124 of each recess 100 correlates to the intensity of the laser beam. The maximum recess depth 124 can vary slightly for different striking face materials. For polished carbon steel, the recess depth 124 described above can be up to 2000 GW / cm. 2 , up to 1500GW / cm 2 , maximum 1000GW / cm 2 , up to 500GW / cm 2 , up to 250GW / cm 2 , up to 100GW / cm 2 , up to 50GW / cm 2 , up to 25GW / cm 2 , up to 10GW / cm 2 , up to 5GW / cm 2 , or up to 1 GW / cm 2For some LSSP processes, the maximum recess depth for a given laser beam intensity can be approximated by the following formula: y=0.0075x+0.5949 where "x" is the intensity of the laser beam and "y" is the approximate maximum recess depth 124 that results from the use of a given laser beam intensity in the LSSP process.

[0062] Each recess 100 has a bottom surface 126. In some embodiments, the recess bottom surface 126 can have a non-uniform profile with ridges, valleys, and other complex geometric shapes. In some embodiments, the recess bottom surface 126 can have a shock wave shape with a curved contour. The shock wave shape and / or non-uniform profile can be created through a laser shock surface patterning (LSSP) process, described below. The contour of the bottom surface 126 can vary due to the grain structure in the region of the recess prior to processing and / or due to the composition of the absorber layer used in the LSSP process. For example, if the absorber layer contains large grains, the shock wave power will be greater, which will affect the shaping of the recess bottom surface 126.

[0063] Figure 9 illustrates the results of an experiment recorded in the publication Mao, Bo & Siddaiah, Arpith & Menezes, Pradeep & Liao, Yiliang. (2018). "Surface Texturing by Indirect Laser Shock Surface Patterning for Manipulated Friction Coefficient," Journal of Materials Processing Tech. vol. 257 (2018) pp. 227-233, which is incorporated herein by reference in its entirety. These graphs have not been modified from their original source, so the vertical axis of "Height (μm)" corresponds to the measurement of "Depth of Indentation" as defined herein. Figure 9 illustrates four example surface profiles, each with multiple indentations. The surface profile of the first example (a) shows a surface with a 0.484 GW / cm2 energy density measured on a polished square carbon steel plate. 2 The first surface profile (a) shows a pattern of depressions with consistent depth (approximately 0.2 μm) and width. The bottom surface of each depression shows a slight protrusion at the center of each bottom surface. The second example surface profile (b) shows a polished square carbon steel plate subjected to laser shock surface patterning with a laser dose of 0.554 GW / cm. 2 The second surface profile (b) was created by laser shock surface treatment with a laser dose of 1000 u. The second surface profile (b) has depressions with a greater depth (approximately 0.5 μm). The bottom surface of each depression is slightly more irregular than in the first surface profile (a).

[0064] The surface profile (c) of the third example is a polished square carbon steel plate with a radiation intensity of 0.778 GW / cm 2 The surface profile (d) of the fourth example was created by laser shock surface treatment with a laser beam dose of 0.890 GW / cm on a polished square carbon steel plate. 2The third example surface profile (c) and the fourth example surface profile (d) have progressively greater depths than profiles (a) and (b). The third example profile (c) and the fourth example profile (d) include peaks and irregular textures extending from the bottom surface. The effect of laser dose on the surface profile is discussed further below.

[0065] The plurality of recesses 50 in the processing region 40 may be characterized by an aspect ratio of recess depth 124 to recess width 120. The aspect ratio may range from 3 to 150. In some embodiments, the aspect ratio can range from 3 to 5, 5 to 10, 10 to 20, 20 to 30, 30 to 40, 40 to 50, 50 to 60, 60 to 70, 70 to 80, 80 to 90, 90 to 100, 100 to 110, 110 to 120, 120 to 130, 130 to 140, 140 to 150, 3 to 25, 25 to 50, 50 to 75, 75 to 100, 100 to 125, 125 to 150, 3 to 50, 25 to 75, 50 to 100, 75 to 125, 100 to 150, 3 to 100, 25 to 125, or 50 to 150. A higher aspect ratio correlates to a rougher surface and a higher coefficient of friction. For aspect ratios above 6, "micro-effects" and "nano-effects" occur, causing the performance of the recesses 50 to be better than expected.

[0066] Referring again to FIG. 2 , the plurality of recesses 50 (recess array) can be arranged in a pattern across the front surface 16. The recess array 50 can include a length 78 measured in a heel-to-toe direction. In some embodiments, the array length 78 is limited by the size of the striking face 12. In some embodiments, such as FIG. 3 , the array length 78 can be equal to the length of one or more face grooves 130, as described further below. The array length 78 can be between 1.5 inches and 2.5 inches. In some implementations, the array length 78 is 1.5 inches to 2.0 inches, 1.8 inches to 2.2 inches, or 2.0 inches to 2.5 inches. In some embodiments, the array length can be 1.5 inches, 1.6 inches, 1.7 inches, 1.8 inches, 1.9 inches, 2.0 inches, 2.1 inches, 2.2 inches, 2.3 inches, 2.4 inches, or 2.5 inches.

[0067] 6-8, recesses 100 may be spaced apart from one another by a separation distance 80 to create a recess array 50. The separation distance 80 may be between 1 μm and 250 μm (approximately 3.9×10 -5 inch to about 0.0098 inches). In some embodiments, separation distance 80 can be 1 μm to 25 μm, 25 μm to 75 μm, 75 μm to 125 μm, 125 μm to 175 μm, 175 μm to 225 μm, or 225 μm to 250 μm. In some embodiments, separation distance 80 can be 25 μm, 50 μm, 75 μm, 100 μm, 125 μm, 150 μm, 175 μm, 200 μm, 225 μm, or 250 μm. Separation distance 80 affects the density of recesses across array 50, which in turn changes the properties of front surface 16, such as the coefficient of friction.

[0068] Multiple regions of the striking face 12 can be treated with recesses 100 having different sizes and / or depths to impart different coefficients of friction to the multiple regions of the striking face. Additionally, the multiple recesses 50 can be arranged or aligned in various patterns, including similar or different shapes, to modify the coefficient of friction, hardness, and / or aerodynamic properties of the surface. For example, in some embodiments, the recesses 100 can be arranged in a second pattern (second array) so that they are spaced further apart than in the first pattern (first array).

[0069] In addition to the recess array 50, the striking face front surface 16 may further include conventional grooves 130. The grooves 130 may extend generally horizontally in a heel-to-toe direction when the club is in the address position. The grooves 130 may be spaced apart from one another in a crown-to-sole direction (or a top rail-to-sole direction). The grooves 130 may be spaced apart by a groove pitch 132 (separation distance) between 2 millimeters (mm) and 3 mm (0.08 inches and 0.12 inches). In some embodiments, the groove pitch 132 is between 2 mm and 2.2 mm, 2.2 mm and 2.4 mm, 2.4 mm and 2.6 mm, 2.6 mm and 2.8 mm, or 2.8 mm and 3.0 mm. In some embodiments, the groove pitch 132 may be 2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, or 3.0 mm. The recess array 50 can fill or partially fill the recessed areas between the grooves 130. In some embodiments, the grooves 130 can have a constant width (width measured from crown to sole / width measured from top rail to sole) and a constant land area between the grooves 130. In other embodiments, the grooves 130 can have a width that varies between the grooves 130 and a land area that varies between the grooves 130. Striking face back surface texturing

[0070] As described above, one or more of the striking face front surface 16, the striking face rear surface, and the sole surface may be textured. The striking face rear surface may have at least one texturing region similar to texturing region 48 described above. The texturing region may include a plurality of recesses that provide texture to the rear surface (not illustrated). The plurality of recesses in the rear surface may be similar to the plurality of recesses 50 in the front surface 16. Similar to the textured front surface, the texturing region on the rear surface may cover between 20% and 100% of the striking face. In some embodiments, the texturing region may cover 20%-30%, 30%-40%, 40%-50%, 50%-60%, 60%-70%, 70%-80%, 80%-90%, or 90%-100% of the rear surface. In some embodiments, the textured region can cover 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100% of the rear surface. Selectively texturing one or more portions of the rear surface can modify the residual stresses in the rear surface, improving the durability, deformation characteristics, and energy storage mechanics of the striking face 16.

[0071] The recesses on the striking face rear surface can have the same respective properties as those described above for the front surface recesses 100: footprint shape, footprint shape area, recess width, recess height, and recess depth. In some embodiments, the striking face rear surface can have a first array of recess shapes, and another section of the rear surface has a second array of recess shapes. In some embodiments having both the striking face front and rear surfaces textured, the recess shapes on the front surface can be different from the recess shapes on the rear surface. In other embodiments having both the front and rear surfaces textured, the recess shapes on the front and rear surfaces can be the same. Multiple regions of the rear surface can be treated with recesses having different sizes and / or heights to impart different grain structures, residual stresses, and / or hardness to the multiple regions of the rear surface.

[0072] As described above, a plurality of recesses can be positioned in an array or pattern throughout the rear surface in a manner similar to array 50 on front surface 16. The array length and / or separation distance between recesses on the rear surface can be similar to that described above for striking face front surface 16. The separation distance affects the density of recesses throughout the array, which in turn changes properties, such as durability, of the rear surface. Sole surface texturing

[0073] In some embodiments, the sole surface includes a plurality of recesses that impart texture to the sole 36. The sole surface can have at least one textured region similar to the textured region 48 described above. The textured region can include a plurality of recesses that impart texture to the sole surface. The recesses (not illustrated) on the sole surface can be similar to the recesses on the front and rear surfaces. The textured region on the sole surface, like the textured front surface and the textured rear surface, can cover between 20% and 100% of the sole surface. In some embodiments, the textured region on the sole can cover 20%-30%, 30%-40%, 40%-50%, 50%-60%, 60%-70%, 70%-80%, 80%-90%, or 90%-100% of the sole surface. In some embodiments, the sole texture region can cover 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100% of the sole surface. Selective texturing of one or more portions of the sole surface can modify the coefficient of friction, hardness, and / or aerodynamic properties of the sole surface. The modified coefficient of friction can improve turf interaction between the sole surface and the ground. The increased hardness of the sole surface can improve the durability of the sole. The modified aerodynamic properties can reduce drag and increase swing speed.

[0074] The recesses on the sole surface can have similar occupancy shapes, occupancy area, recess width, recess height, and recess depth as those described above for the recesses on the front and rear surfaces. In some embodiments, the sole surface can have a first array of recess shapes, and another section of the sole surface has a second array of recess shapes. In embodiments having both a textured striking face and a textured sole, the recess shapes on the striking face can be different from or the same as the recess occupancy shapes on the sole. In some embodiments, multiple regions of the sole surface can be treated to have recesses with different sizes and / or depths, imparting different grain structures and / or different residual stresses to the multiple regions of the sole surface. The treated regions of the sole surface can have different hardness values. The recess depth of the array on the sole surface can also affect the aerodynamic response and turf interaction of the sole surface.

[0075] As described above, the plurality of recesses can be positioned in an array or pattern across the sole 36. The array of recesses on the sole surface can cover a portion of the sole 36 or the entire sole 36. The array of recesses on the sole surface can have a length measured in the heel-toe direction. In some embodiments, the array length is limited by the size of the sole 36. In some embodiments, the array length on the sole can be longer than the array length on the front or rear surfaces of the striking face. The array length on the sole can be between 1.5 inches and 3.5 inches. In some embodiments, the array length is between 1.5 inches and 2.0 inches, between 1.8 inches and 2.2 inches, between 2.0 inches and 2.5 inches, between 2.5 inches and 3.0 inches, or between 3.0 inches and 3.5 inches. In some embodiments, the array length is 1.5 inches, 1.6 inches, 1.7 inches, 1.8 inches, 1.9 inches, 2.0 inches, 2.1 inches, 2.2 inches, 2.3 inches, 2.4 inches, 2.5 inches, 2.6 inches, 2.7 inches, 2.8 inches, 2.9 inches, 3.0 inches, 3.1 inches, 3.2 inches, 3.3 inches, 3.4 inches, or 3.5 inches.

[0076] The recesses of the plurality of recesses may be spaced apart from one another by a separation distance to create a recess array on the sole surface. The recesses of the plurality of recesses on the sole surface may be spaced apart by a separation distance similar to the separation distance 80 described above for the recess array 50 on the front surface of the striking face. The separation distance affects the density of the recesses across the array, which in turn changes the durability, aerodynamics, and / or turf interaction properties of the sole surface. Alternative Embodiment with Crown Surface Texturing

[0077] In alternative embodiments (not shown), other body surfaces on the golf club head can be textured. For example, in wood-type golf club heads (drivers, fairways, and hybrids), the crown surface of the club head can include at least one textured area having a plurality of recesses that impart texture to the crown. In wood-type embodiments having a textured crown surface, the array width can be between 1.5 inches and 4.5 inches. In some embodiments, the array length is 1.5 inches to 2.0 inches, 1.8 inches to 2.2 inches, 2.0 inches to 2.5 inches, 2.5 inches to 3.0 inches, 3.0 inches to 3.5 inches, 3.5 inches to 4.0 inches, or 4.0 inches to 4.5 inches. In some embodiments, the array width is 1.5 inches, 1.6 inches, 1.7 inches, 1.8 inches, 1.9 inches, 2.0 inches, 2.1 inches, 2.2 inches, 2.3 inches, 2.4 inches, 2.5 inches, 2.6 inches, 2.7 inches, 2.8 inches, 2.9 inches, 3.0 inches, 3.1 inches, 3.2 inches, 3.3 inches, 3.4 inches, 3.5 inches, 3.6 inches, 3.7 inches, 3.8 inches, 3.9 inches, 4.0 inches, 4.1 inches, 4.2 inches, 4.3 inches, 4.4 inches, or 4.5 inches. All other parameters of the crown recess array, such as recess width, recess height, recess depth, and separation distance, can be similar to the respective parameters of the striking face front surface recess array 50. Properties / Characteristics / Performance

[0078] The textured or treated surface of a golf club head can exhibit a different coefficient of friction, roughness, hardness, material grain structure, and / or residual stress than an untreated surface. One or more of these parameters can affect spin rate, launch angle, and / or ball speed. Additional benefits may include efficient and rapid manufacturability, increased material fatigue resistance, and / or increased wear resistance.

[0079] The size and shape of the recesses on the front surface 16, rear surface, and / or sole surface can determine the coefficient of friction of each of these surfaces. The coefficient of friction between a urethane-covered golf ball and a textured front surface, a textured rear surface, and / or a textured sole surface can range from 0.05 to 0.95. In some embodiments, the textured surface coefficient of friction between a urethane-covered golf ball and a textured surface can range from 0.10 to 0.30, 0.40 to 0.95, 0.40 to 0.50, 0.50 to 0.60, 0.60 to 0.70, 0.70 to 0.80, 0.80 to 0.90, or 0.85 to 0.95. In some embodiments, the textured surface coefficient of friction can be 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, or 0.95. In some embodiments, the textured surface coefficient of friction can be less than 0.1, less than 0.2, less than 0.3, less than 0.4, less than 0.5, less than 0.6, less than 0.7, less than 0.8, less than 0.9, or less than 0.95.

[0080] In some embodiments, the treated striking face front surface 16 and / or sole surface have a higher coefficient of friction than the untreated striking face and / or sole, respectively. In other embodiments, the treated striking face front surface 16 and / or sole surface have a lower coefficient of friction than the untreated striking face and / or sole, respectively. In embodiments where the recesses are formed by laser shock surface processing (LSSP), the coefficient of friction of the textured surface is determined by the amount of laser light used during manufacturing. The striking face coefficient of friction controls the spin imparted to the golf ball upon impact. The sole coefficient of friction affects the turf interaction between the sole surface and the ground.

[0081] The coefficient of friction between the ball and the striking face 12 controls the amount of spin imparted to the golf ball upon impact. The loft angle of the club head 10 can change the relationship between the striking face coefficient of friction and golf ball spin rate. For low-loft clubs, a higher coefficient of friction can impart lower spin rates to the ball, whereas for high-loft clubs, a higher coefficient of friction can impart higher spin rates to the ball. For most low-loft club heads, lower spin is desirable because it can produce longer carry distance. For example, for driver-type clubs, lower spin increases carry distance and allows the golf ball to roll forward after landing. However, for high-loft clubs, higher spin increases ball flight distance. Higher spin can also cause the ball to remain stationary or roll slightly backward upon landing, thereby increasing shot accuracy.

[0082] In addition to loft angle affecting the relationship between the coefficient of friction and spin rate, the conditions under which the shot is taken can also affect that relationship. Specifically, for high-loft club heads in dry conditions, the amount of ball spin imparted may not be affected by adding texture to the front striking face surface. However, in wet conditions, the amount of ball spin imparted can be increased by texturing the front striking face surface 16. The added texture can increase spin by up to 2000 revolutions per minute (rpm). In some embodiments, the textures described herein can increase spin rate under wet conditions by between 500 rpm and 2000 rpm, between 500 rpm and 700 rpm, between 700 rpm and 900 rpm, between 900 rpm and 1100 rpm, between 1100 rpm and 1300 rpm, between 1300 rpm and 1500 rpm, between 1500 rpm and 1700 rpm, between 1700 rpm and 1900 rpm, or between 1800 rpm and 2000 rpm. In some embodiments, the added texture can increase spin rate under wet conditions by between 5% and 30%, more specifically, between 5% and 10%, between 10% and 15%, between 15% and 20%, or between 20% and 30%. In some embodiments, the added texture can increase spin rate by approximately 13.5%. Wet conditions tend to be more common during golfing because dew or other moisture often remains on the turf, and therefore improving spin rate and other performance parameters in wet conditions is particularly important to golfers.

[0083] Increased ball spin improves shot accuracy by helping the golf ball stay near the point of impact with the ground, rather than rolling forward. Furthermore, striking faces lacking the texture described herein tend to induce lower spin rates in wet conditions than in dry conditions. For club heads with the texture described herein, the induced spin rates can be approximately the same in wet and dry conditions. Similar spin rates between wet and dry conditions can improve a golfer's ability to predict their shot distance.

[0084] Texturing the striking face front surface 16 can also reduce the launch angle of a golf ball in wet conditions. In wet conditions, the striking face front surface texture can reduce the launch angle by between 1 and 3 degrees compared to a striking face lacking the texture described herein. In some embodiments, the striking face front surface texture can reduce the launch angle by approximately 1 to 1.5 degrees, 1.5 to 2.0 degrees, or 2.5 to 3.0 degrees. Reducing the launch angle can improve shot performance for wedge-type or iron-type club heads. Texturing the striking face front surface 16 can also increase the potential ball speed imparted to a golf ball in wet conditions. On average, the striking face front surface texture does not negatively affect ball speed.

[0085] In some embodiments, the textured or treated surface may have a Vickers hardness (HV) of 70 to 90, 70 to 75, 75 to 80, 80 to 85, 85 to 90, or 75 to 85. The textured or treated surface may have a Vickers hardness (HV) that is 10 to 20 points greater than the hardness of the untreated surface. In some embodiments, the hardness and fine grain structure of the plurality of recesses can reduce crack initiation and slow crack propagation on the striking face front surface. In other words, the potential ball speed achievable with an untextured striking face is maintained after texturing the striking face front surface 16.

[0086] As described above, the textured or treated surface of a golf club head can exhibit a coefficient of friction, material grain structure, hardness, and / or residual stress that differs from the untreated surface. One or more of the front surface, rear surface, and / or sole surface (i.e., the treated surface) can have a fine grain structure. The laser impact surface patterning process, which creates recesses on the treated surface, can modify the material's grain structure. When the treated surface undergoes a microforging process, dislocations or voids at the grain boundaries are permanently compressed. This results in a finer grain structure than the original grain structure. The finer grain structure makes the treated surface resistant to crack initiation and propagation because the voids at the grain boundaries are compressed. In other words, forging recesses in the striking face can increase the face's fatigue resistance, allowing the club head to withstand more impacts from golf balls before failing.

[0087] The textured or treated surface may have compressive residual stresses. In embodiments having a treated striking face rear surface, the compressive stresses caused by the micro-forged recesses can offset the tensile stresses imparted to the rear surface during impact. This offset of tensile stresses allows the striking face to be more durable and better able to store impact energy.

[0088] The LSSP process can also be used to relieve stress within the weld zone. To create a complete golf club head, a striking face is often welded to the club head body. The resulting weld zone, or heat-affected zone (HAZ), contains stressed metallic material that is more prone to fracture than adjacent metallic components. Treating the weld zone or HAZ with LSSP can improve durability by relieving stress within the welded metallic material. The laser shock surface patterning process microforges the treated surface, which alters the texture, hardness, and material grain structure of the surface.

[0089] Finally, texturing one or more surfaces of a golf club head using LSSP can improve the aerodynamic properties of the treated surface. The use of texturing to achieve aerodynamic benefits is particularly useful for crown and / or sole surfaces. The modified surface structure created by LSSP can improve laminar air flow over the surface. Improving laminar air flow over the crown and / or sole surfaces can reduce overall drag on the club head, increasing swing speed and resulting ball speed. method

[0090] 10 , the method for manufacturing a striking face described above includes: providing a golf club head having a striking face, which in some embodiments includes providing a striking face (step 150); disposing a mask layer on the striking face's front surface and applying an absorbent (or ablation) layer above the mask layer (step 152); disposing a containment layer above the absorbent layer (step 154); forging an array or a portion of an array of recesses by focusing a laser beam above a spot on the striking face and laser impacting the absorbent layer (step 156); repeating steps 154 and 156 while aiming the laser at an untreated spot on the striking face to remove the containment layer and the mask layer (step 158) until the desired portion of the striking face's front surface has been treated; and cleaning the striking face, if necessary. For the purposes of the following discussion, the reference numbers used above for the golf club head 10 will also be used in describing this method. However, the method for manufacturing a striking face is not limited to the specific wedge-type golf club head 10.

[0091] In process step 150, providing the striking face 12 may include casting, forging, stamping, 3D printing, or otherwise forming the striking face 12. The laser shock surface patterning (LSSP) process requires that the treated portion of the front surface be flat or planar. Therefore, step 100 may further include grinding, polishing, lapping, or otherwise forming at least one flat area on the front surface 16. For some golf club heads, the entire striking face front surface 16 is ground, polished, lapped, or otherwise formed to be flat or planar. The flatter the surface, the more efficient the LSSP process.

[0092] In step 152, a mask layer 140 is placed over the striking face front surface 16. In some embodiments, the mask layer 140 can be a mesh, such as a metal mesh or wire cloth. The mask layer 140 can also be referred to as a protective mold layer or a mesh layer. The mask layer 140 can have apertures corresponding to the desired occupancy shape of the recesses 100 created by the laser shock forging (LSSP) process. The mask layer 140 can be graded by the number of apertures per linear inch. The mask 140 can be 400 mesh, with 400 evenly spaced apertures per inch. In other embodiments, the mask 140 may be 200 mesh, 225 mesh, 250 mesh, 275 mesh, 300 mesh, 325 mesh, 350 mesh, 375 mesh, 400 mesh, 425 mesh, 450 mesh, 475 mesh, 500 mesh, 525 mesh, 550 mesh, 575 mesh, 600 mesh, 625 mesh, 650 mesh, 675 mesh, or 700 mesh. In some embodiments, several separate mask layers are used to form different recess patterns on different portions of the striking face 12.

[0093] In step 154, an absorber layer 142 is applied over the mask layer 140. The absorber layer 142 may also be referred to as a plasma-generating layer or an ablation layer. The material forming the absorber layer 142 should be carbon-based and black or very dark in color. In some embodiments, the absorber layer material is graphite, graphene, or any other suitable carbon-based material. In some embodiments, the absorber layer 142 can be tape. The absorber layer 142 can be taped, sprayed, painted, poured, laid down, or otherwise applied to the mask layer 140. In some embodiments having a tape-type absorber layer 142, the tape can be used to hold the mask layer 140 in place. The absorber layer 142 absorbs energy from the laser beam 146, converting the material of the absorber layer 142 into a plasma state. The color of the carbon-based material allows it to absorb the energy transmitted by the laser beam 146 applied in step 156.

[0094] In embodiments using graphene as the material for the absorbing layer 142, the uniform geometry of the graphene platelets can absorb laser energy more efficiently than other carbon materials. Because of its structure, graphene can have a larger surface area exposed to the laser beam 156 compared to other carbon materials. In some embodiments, the absorbing material is a spray (or sticky paint), while in other embodiments, the material is a powder. The material for the absorbing layer 142 can be provided as particles of various sizes. The size of the absorbing layer particles can affect the power of the resulting shockwave. For example, larger particles can generate more plasma, resulting in a higher-power shockwave, while smaller particles result in a lower-power shockwave. The absorbing layer 142 can also include air or other trace elements trapped within the primary material of the layer.

[0095] In step 154, containment layer 144 is placed over absorbent layer 142. Containment layer 144 is formed of a transparent, airtight material. In some embodiments, containment layer 144 is water. In other embodiments, containment layer 144 is a sheet of glass. The sheet of glass must be flat to ensure an airtight seal against absorbent material 142. If containment layer 144 is water, absorbent material 142 can be a spray, tape, or sticky paint that does not wash off (powder is more likely to wash off). If containment layer 144 is a sheet of glass, containment layer 144 is preferably a powder.

[0096] In step 156, a laser beam 146 is focused above a spot on the striking face front surface 16. Energy from the laser beam 146 is transmitted through the transparent containment layer 144 (water in this example) and into the absorbing layer 142. When the laser 146 strikes the absorbing layer 142, it is ablated and then ionized. The laser shock converts the absorbing layer 142 to a plasma state. This creates a shock wave 148 that impacts the surface below. The shock wave 148 exhibits rapid changes in pressure, temperature, and density in the absorbing layer 142. The mask layer 140 prevents the plasma from affecting the mesh-covered portions of the striking face front surface 16. However, the apertures in the mask layer 140 allow the plasma shock wave 148 to pass through the apertures and reach the exposed microscopic surface areas. The shock wave 148 forges these exposed microscopic surface areas into depressions 100. A single pulse of laser 146 can forge multiple depressions 100 through plasma generation caused by shock waves 148 .

[0097] The size of the laser beam 146 does not determine the size of the recesses 100. Rather, the size of the recesses 100 is determined by the mask layer 140. The recesses 100 correspond to the size of the apertures in the mask layer 140. Use of the mask layer 140 allows the recess size to be adjusted to a desired size to create a desired texture or roughness of the striking face front surface 16. The texture of the front surface 16, in turn, determines the coefficient of the striking face 12.

[0098] As described above, the amount of light emitted by the laser beam 146 can affect the coefficient of friction. In some embodiments, increasing the amount of light emitted by the laser beam 146 can increase the coefficient of friction. However, in some embodiments, the coefficient of friction can be initially reduced compared to an untreated striking face. The amount of light emitted by the laser beam 146 can also affect the hardness of the striking face. In some embodiments, and for some striking face materials, the hardness of the striking face 12 can be increased by using a higher laser beam amount.

[0099] The process of laser shock treating the surface (LSSP) can be repeated until every area of ​​the striking face 12 where texturing is desired has been textured. In some embodiments, the entire striking surface 16 is textured. In some embodiments, only a portion of the striking face front surface 16 is textured. Repeating this process is necessary because the size of the laser beam 146 is small compared to the striking face 12. In some embodiments of this method, the step 156 of laser shocking a small surface area can be repeated between 300 and 400 times to texture the entire striking face front surface 16.

[0100] Each laser shock 148 covers an approximately 3 x 3 mm grid (0.09 cm 2The forging process (covering an area of ​​100 mm) can be completed in between 3 nanoseconds and 25 nanoseconds. Accounting for the time required for the application of containment layer 144, absorber layer 142, and mask layer 140, each recess 100 can be created in between 0.4 microseconds and 0.8 microseconds. In some embodiments, each recess can be created in 0.6 microseconds. The high speed of forging the recesses 100 allows for the rapid manufacture of the striking face 12, as compared to slower methods lacking the mask layer 140.

[0101] In some embodiments, the surface being treated is a curved surface. The laser shock surface patterning (LSSP) process requires a flat surface over at least the entire local treatment area. Thus, a curved surface can be treated by dividing the surface into multiple locally flat surface areas. These flat areas allow for the local application of multiple recesses through the laser shock surface patterning process.

[0102] In step 158, the containment layer 144 and mask layer 140 are removed from above the striking face 12. In some embodiments, this requires draining water from above the absorbent layer 142. The treated surface can be cleaned after laser shock processing (LSSP) is complete. Any residue left behind by removing the absorbent layer 142 can be wiped or otherwise removed from the striking face 12.

[0103] The above method may be referred to as indirect laser shock processing (or indirect laser shock surface patterning). In some embodiments, the methods of producing golf club heads described herein include a direct laser shock processing method, in which a mask layer 140 is placed over the absorbing layer 142 to shield the absorbing layer 142 from the laser beam 146. In an alternative embodiment of the method of forming a striking face disclosed herein, laser shock processing (LSSP) can be applied to a sheet of metal, from which the striking face 12 can then be cut.

[0104] A method for manufacturing the striking face rear surface, sole surface, and / or crown surface includes steps similar to those for treating the striking face front surface 16. A manufacturing method for producing a golf club head having one or more treated surfaces may include: providing a golf club head body to provide a striking face; placing a mask layer over the surface to be treated; applying an absorbent layer over the mask layer; placing a containment layer over the absorbent layer; forging a recess array or a portion of the recess array by focusing a laser beam over a spot on the surface to be treated and laser impacting the absorbent layer; repeating the laser impact process by aiming the laser at an untreated spot on the surface until the desired portion of the surface is treated; removing the containment layer and mold layer; and cleaning the surface, if necessary. This method can be applied to the striking face rear surface, sole surface, and / or crown surface. In some embodiments, one or more of the striking face front surface, striking face rear surface, sole surface, and / or crown surface are treated more than once according to this manufacturing method. By treating the surface more than once, it is possible to change the shape of the depressions, increase the hardness of the surface, and / or change the depth of the depressions. Production Equipment

[0105] Manufacturing a striking face 12 having the texture described herein may require a production apparatus. Typically, the production apparatus includes a means for retaining the striking face 12, a crown insert, a sole insert, and / or a golf club head body with a crown and sole. The production apparatus further includes a casing that retains and / or encloses the mask layer 140, the absorbent layer 142, and the containment layer 144.

[0106] In some manufacturing scenarios, procuring a mask layer (or mesh) the size of the striking face can be costly to create recesses having widths of 1.2 μm or less. Therefore, to reduce production costs, a small mesh, commonly known as a TEM grid, can be used instead of a mask layer the size of the striking face. TEM grids are readily available and affordable on the market because they are commonly used in transmission electron microscopy.

[0107] In some embodiments, the production apparatus may include a base plate for holding a club head, a frame, and a number of pins (not shown) for removably retaining the frame to the base plate. The frame can slide when the pins are not in place. FIGS. 12 and 13 illustrate a production apparatus 200 lacking a means for holding a club head but operating in the same manner as a production apparatus having a means for holding a club head. A frame 230 rests on the base plate 210. The frame 230 houses a TEM grid. The frame 230 is retained in either a first position or a second position relative to the base plate 210. FIG. 13 shows the frame 230 in the second position. In the first position, the frame 230 can be positioned slightly higher than in the second position. Because the frame 230 determines where the laser shock surface treatment is applied, the position of the frame 230 controls which area of ​​the striking face is treated.

[0108] 13 and 14, the base plate 210 includes a top surface 212, a bottom surface (not shown), a means for clamping a golf club head (not shown), a plurality of holes 218 for receiving fasteners, and a plurality of pin holes 222, 224 for receiving pins. In some embodiments, a void (not shown) is formed in the top surface 212. The void is shaped to hold the golf club head with the striking face facing upward. The striking face can be positioned parallel to the top surface 212.

[0109] The base plate 210 itself can be secured to the laser table via a plurality of holes 218 and fasteners (not shown). In some embodiments, a clamp or other fastening mechanism is used to hold the golf club head within the cavity. In some embodiments, the top surface 212 of the base plate 210 includes two tracks 228 that engage the frame 230, allowing the frame 230 to slide from a first position to a second position. In other embodiments, the base plate top surface 212 lacks tracks 228. In these embodiments, the frame 230 can be lifted and moved from a first position to a second position.

[0110] The frame 230 has a top surface 232 and a bottom surface (not shown). Typically, the frame 230 is formed from a thick metal plate. The frame 230 has a plurality of apertures 238 sized to receive the TEM grid. The plurality of apertures 238 are aligned across the frame 230. Each aperture extends through the frame 230 from the top surface 232 to the bottom surface. Each aperture may have a diameter. The apertures 238 may be spaced apart by a distance less than the aperture diameter. The plurality of apertures 238 may include between 40 and 80 apertures. In some embodiments, the plurality of apertures 238 includes 40, 45, 50, 55, 60, 65, 70, 75, or 80 apertures.

[0111] The frame 230 further includes clamp tabs 236. The clamp tabs 236 extend outward from two or more sides of the frame 230. The clamp tabs 236 allow the frame 230 to be secured to the worktable and / or base plate 210. Retaining the frame 230 is important for maintaining a watertight seal between the base plate 210 and the frame 230. A watertight seal is necessary because deionized water is often used as a containment layer.

[0112] The frame 230 further includes a plurality of pin holes 240 for receiving pins. When the frame 230 is in a first position, at least one of the base plate pin holes 222, 224 corresponds to at least one of the frame pin holes 240. When the frame 230 is positioned in a second position, a different base plate pin hole 222, 224 corresponds to a different frame pin hole 240. In this manner, when the frame is in the first position, only the first set of pin holes 222 are used, and when the frame is in the second position, only the second set of pin holes 224 are used. This allows an operator to easily identify which position the frame is in. At least one pin is placed through at least one pin hole to hold the frame 230 properly aligned in either the first or second position.

[0113] One exemplary method of using the production apparatus 200 may include first bolting a base plate 210 onto a laser table. A golf club head is secured to the base plate 210. A frame 230 is aligned above the base plate 210 and the club head striking face. The frame 230 is aligned with the base plate 210 in a first position. The frame 230 is clamped onto the base plate 210 and the striking face. A plurality of TEM grids (acting as a masking layer) are inserted into the plurality of apertures 238 of the frame 230. Carbon powder or graphene powder (acting as an absorbing layer) is packed into the plurality of apertures 238 to coat the TEM grids. The plurality of apertures 238 are further filled with deionized water (acting as a containment layer). An Nd-YAG laser is fired through each aperture of the plurality of apertures 238 to peen (or forge) the portion of the striking face below each aperture.

[0114] The frame 230 is removed or cleaned. The frame 230 is placed on the base plate 210 in a second location. The process of preparing and treating the face is repeated in the second location. Because the frame 230 has shifted, a new area of ​​the face is treated. In this manner, a large portion of the striking face surface area can be treated in a time-efficient and cost-effective manner. Example Example 1 - Robot Testing

[0115] An example golf club head having a textured striking face front surface was compared with a control golf club head having a striking face front surface lacking the texture. The example golf club head was a wedge-type golf club head with a loft angle of 58 degrees. The example golf club head had a striking face and body similar to the golf club head 10 described above. The example golf club head was formed from 8620 alloy steel. The striking face had a front surface with a plurality of recesses.

[0116] In the example club head, the recesses on the front surface of the striking face were square shaped. Each recess of the plurality of recesses occupied an area of ​​about 1369 μm 2 (0.00000225in 2 ), had a width of about 37 μm (0.0015 inches), a height of about 37 μm (0.0015 inches), and a maximum depth of about 600 μm (0.0232 inches). The plurality of recesses were organized into rows of recesses. The rows were oriented horizontally (heel-toe) when the golf club head was in the address position. Each recess was spaced from each adjacent recess by a separation distance of about 37 μm (0.0015 inches). Using the LSSP process, the plurality of recesses was formed in the striking face of the example golf club head. The control golf club head was identical to the example golf club head except that the control lacked the plurality of recesses on the front surface of the striking face.

[0117] The depressions were applied in groups, where the depressions in each group were arranged in a circle (similar to pocket region 62 above) with a diameter of 2 mm. Each group of depressions had a duration of 7 ns and an energy density of 1 GW / cm. 2 The LSSP textures / depressions were fabricated with a single laser pulse of 0.1 mm. The groups of depressions were arranged side by side in the heel-toe direction, with a distance of approximately 0.1 mm between the edges of each circular shape with a diameter of 2 mm. The groups of depressions cannot overlap. Therefore, achieving a minimum separation distance between the groups is essential to cover the surface with the LSSP texture / depressions.

[0118] Three performance parameters were tested: launch angle, ball speed, and ball spin. Each parameter was tested under both dry and wet conditions. For wet condition testing, both the ball and the club head were exposed to moisture before each test shot. Comparisons were made using a robot programmed to swing the golf club in the same manner for each shot. Fifteen shots were taken under dry conditions and fifteen shots were taken under wet conditions. Data presented below are the average of these 15-shot sets. Statistical areas corresponding to where the shots stopped were also measured for both clubs to illustrate the potential shot accuracy of each test club.

[0119] As illustrated in the graph of FIG. 15, under dry conditions, the launch angles of the example club heads were nearly comparable to those of the control club head. In this test, the launch angles were approximately 31.5 degrees for the control and approximately 31.4 degrees for the example club head, with an error bar of approximately 0.2 degrees. However, under wet conditions, the launch angles of the example club heads were approximately 2.2 degrees less than the launch angle of the control club head, with an error bar of approximately 0.7 degrees. The launch angles were approximately 33.1 degrees for the control and approximately 30.9 degrees for the example club head. The lower launch angle of the example club heads allows the ball to travel a more accurate distance. Because wind strength increases the higher the distance above the ground, a lower launch angle reduces the time the golf ball is exposed to windy conditions at high altitudes. As can be seen from the above data, the example club heads exhibited launch angles in wet conditions that were closer to their launch angles in dry conditions. This similarity in performance across conditions creates greater consistency for golfers, allowing them to better predict shot performance.

[0120] As illustrated in the graph of FIG. 16, under dry conditions, the spin rate imparted to a golf ball by the example club head was comparable to that imparted by the control club head. In this test, the average spin rate under dry conditions was approximately 10,222 rpm for the control and 10,206 rpm for the example club head, with error bars ranging from 100 rpm to 300 rpm. Under wet conditions, the spin rate imparted by the example club head was significantly higher than that imparted by the control club head. Under wet conditions, the example club head imparted an average spin rate of approximately 10,578 rpm, with an error bar of approximately 500 rpm. Under wet conditions, the control club head imparted an average spin rate of approximately 9,316 rpm. Therefore, under wet conditions, the example club head imparted a spin rate that was approximately 13.5% faster than that imparted by the control club head. This higher spin rate helps the golf ball to stop near the point where the shot initially impacts the ground. Reducing the amount of spin reduces the rolling of the ball after it lands, thereby improving shot accuracy.

[0121] The spin rate data also shows that the example club heads have more consistent spin rates across dry and wet conditions than the control club heads. For the control club heads, the average spin rate differs by approximately 906 rpm between dry and wet conditions. For the example club heads, the average spin rate differs by approximately 372 rpm between dry and wet conditions. Therefore, because the average spin rate differs less between dry and wet conditions for the example club heads, golfers can better predict shot performance with the example club heads.

[0122] As illustrated in the graph of FIG. 17 , the ball speed imparted by the example club head was slightly lower under dry conditions and slightly higher under wet conditions compared to the control club head. Therefore, the ball speed was more consistent across conditions. Under dry conditions, the ball speed imparted by the control club head was approximately 76.2 mph with an error bar of approximately 0.3 mph. Under dry conditions, the ball speed imparted by the example club head was approximately 75.8 mph with an error bar of approximately 0.3 mph. Under wet conditions, the ball speed imparted by the example club head was approximately 75.1 mph with an error bar of approximately 0.4 mph. The ball speed imparted by the control club head was approximately 74.8 mph with an error bar of approximately 0.6 mph. This data indicates that, when considering the overall performance of the club head, the texture on the striking face of the example club head does not have a significant negative or positive impact on ball speed.

[0123] The plot in Figure 18 shows the statistical area determined by where the test shots landed. Shots hit with the example club head were approximately twice as accurate as shots hit with the control club head. The statistical area for the control club head was approximately 18 square yards, while the statistical area for the example club head was approximately 7 square yards. Shots hit with the control club head carried approximately 85 to 92 yards and had a downline dispersion of approximately 7 yards. Shots hit with the example club head carried approximately 87 to 90 yards and had a downline dispersion of approximately 3 yards. Additionally, the example club head also exhibited less off-line (left or right) dispersion than the control club head.

[0124] The comparative testing further demonstrated that when the striking face was textured using the LSSP process, the coefficient of friction between the front surface of the striking face and a urethane golf ball under wet conditions increased by approximately 40% to 45%. In other words, the striking faces of the example club heads exhibited a coefficient of friction that was 40% to 45% higher than the coefficient of friction of the striking faces of the control club heads.

[0125] In summary, the example club heads exhibited lower launch angles, higher spin rates, and a higher coefficient of friction between the golf ball and the striking face than the control club heads. These factors provide golfers with greater accuracy in their shots. The test further verified this increased shot accuracy through statistical area plots. Example 2 - Prospective Player Testing

[0126] A prospective player test comparison is conducted between an example golf club head having a textured striking face front surface and a control golf club head having a striking face front surface lacking the texture. For this comparison test, 15 to 20 golfers hit shots using the test golf club. The example golf club head is a wedge-type golf club head identical to the example golf club head in Example 1 above. Briefly, the example golf club head has a striking face front surface having a plurality of square-shaped recesses, each of which occupies an area of ​​approximately 1369 μm. 2 (0.00000225in 2 ) and has a maximum depth of about 600 μm (0.0232 inches). The plurality of recesses is formed through the LSSP process. The control golf club head is identical to the example golf club head, except that the control lacks the plurality of recesses on the front surface of the striking face.

[0127] Three performance parameters were tested: launch angle, ball speed, and ball spin. Each parameter was tested under realistic wet conditions. Shots were taken from grass turf maintained to match fairway conditions on a golf course. Each golfer alternated between a golf club with an example head and a golf club with a control head every five shots, hitting a total of 10 shots with each golf club. Statistical areas corresponding to where these shots stopped were also measured for both clubs to illustrate the potential shot accuracy of each test club. The coefficient of friction between the striking face and the urethane golf ball was calculated from the launch angle and ball spin results.

[0128] The launch angle of the example club head is expected to be approximately 2 degrees less than the launch angle of the control club head. The lower launch angle of the example club head is expected to propel the ball a more accurate distance.

[0129] The spin rate imparted by the example club heads is expected to be significantly higher than the spin rate imparted by the control club heads. The example club heads are expected to impart an average spin rate that is approximately 1,000 rpm higher than the control club heads. The example club heads are expected to impart a spin rate that is approximately 10% to 20% faster than the spin rate imparted by the control club heads. This higher spin rate helps the golf ball to stop closer to where the shot initially impacts the ground, improving shot accuracy.

[0130] Ball speeds are expected to be between 70 mph and 80 mph. Ball speeds imparted by the example club heads are expected to be approximately 0.5 mph higher than ball speeds imparted by the control club heads. Statistical areas are determined by where the test shots land. Shots hit with the example club heads are expected to be more than twice as accurate as shots hit with the control club heads. Additionally, the example club heads are expected to exhibit less off-line (left or right) dispersion than the control club heads.

[0131] Additionally, the example club head striking faces are expected to exhibit a coefficient of friction (based on a urethane-coated golf ball) that is 40% to 45% higher than the coefficient of friction of the control club head striking face. In summary, the example club heads are expected to exhibit lower launch angles, higher spin rates, and a higher coefficient of friction between the golf ball and striking face than the control club head. This testing is further expected to demonstrate increased shot accuracy by texturing the striking face using LSSP. Example 3 - Laser Intensity vs. Recess Depth

[0132] A prospective experiment was conducted to demonstrate the correlation between laser dose and recess depth. Table I below shows some maximum expected recess depths for a particular laser dose. [Table 1] Approximately 0.484GW / cm 2 Treating the striking face with the LSSP process using a laser dose of about 0.554 GW / cm is expected to result in a maximum depression depth of about 0.2 μm. 2 Treating the striking face with the LSSP process using a laser dose of about 0.778 GW / cm is expected to result in a maximum depression depth of about 0.5 μm. 2Treating the striking face with the LSSP process using a laser dose of about 0.890 GW / cm is expected to result in a maximum crater depth of about 0.8 μm. 2 Treating the striking face with the LSSP process using a laser dose of about 575 GW / cm is expected to result in a maximum recession depth of about 0.9 μm. 2 Treating the striking face with the LSSP process using a laser dose of about 1920 GW / cm is expected to result in a maximum recession depth of about 4.9 μm. 2 Treating the striking face with the LSSP process using a laser dose of about 15 μm is expected to result in a maximum pit depth of about 15 μm. As outlined by these prospective results, this experiment is expected to show that increasing the laser dose also results in an increase in the maximum pit depth.

[0133] The results of this prospective experiment are expected to be similar to those reported in the publication "Surface Texturing by Indirect Laser Shock Surface Patterning for Manipulated Friction Coefficient" by Mao, Bo & Siddaiah, Arpith & Menezes, Pradeep & Liao, Yiliang. (2018). Journal of Materials Processing Tech. vol. 257 (2018) pp. 227-233. The Mao et al. publication teaches that higher laser power can result in greater crater depth. In their experiments, the crater depth increased from approximately 0.2 μm to approximately 0.9 μm as the laser power increased from approximately 0.5 GW / cm² to approximately 0.9 GW / cm².

[0134] Because the Rules of Golf may change from time to time (e.g., new Rules may be adopted, or old Rules may be repealed or modified, by golf's standards and / or governing bodies), golf equipment related to the methods, apparatus, and / or articles of manufacture described herein may conform or non-conform with the Rules of Golf at any particular time. Accordingly, golf equipment related to the methods, apparatus, and / or articles of manufacture described herein may be advertised, marketed, and / or sold as conforming golf equipment or non-conforming golf equipment. The methods, apparatus, and / or articles of manufacture described herein are not limited in this respect.

[0135] Although a particular order of operations is described above, these operations may be performed in other temporal sequences. For example, two or more operations described above may be performed sequentially, in parallel, or simultaneously. Alternatively, two or more operations may be performed in the reverse order. Moreover, one or more operations described above may not be performed at all. The apparatus, methods, and articles of manufacture described herein are not limited in this respect.

[0136] While this invention has been described in terms of various embodiments, it will be understood that the invention is capable of further modifications. This application is intended to cover any variations, uses, or adaptations of this invention which generally follow the principles of the invention and which come within known and customary practice in the art to which this invention pertains, including departures from the present disclosure. item

[0137] Item 1: A golf club head comprising: a body having a heel end and a toe end; and a striking face having a geometric center, the striking face having a front surface, the front surface comprising a plurality of recesses, each recess having a center point, one or more sidewalls, and a bottom surface, each recess having an occupied area measured as an area enclosed by the sidewalls in a plane coincident with the front surface, the occupied area being less than 0.01 μm2 to 250,000 μm 2 each recess has a maximum depth, measured perpendicular to the front surface from the bottom surface to a plane coincident with the front surface, the maximum depth being between 0.1 μm and 15 μm; and each recess has a width, measured in a heel-to-toe direction through the center point of the recess, the width being between 0.1 μm and 500 μm.

[0138] Item 2: The golf club head of item 1, wherein each recess has a height measured in a sole-to-top rail direction through the center point of the recess, and the height is between 0.1 μm and 500 μm.

[0139] Item 3: The golf club head of item 1, wherein the coefficient of friction between the front surface and a urethane-coated golf ball is between 0.05 and 0.95.

[0140] Item 4: The golf club head of item 1, wherein the occupied area of ​​each recess has a shape selected from the group consisting of a square shape, a triangular shape, a rectangular shape, a circular shape, and a hexagonal shape.

[0141] Item 5: The golf club head of item 1, wherein the one or more side walls include a number of side walls selected from the group consisting of one side wall, two side walls, three side walls, four side walls, five side walls, six side walls, seven side walls, eight side walls, nine side walls, and ten side walls.

[0142] Item 6: The golf club head of item 1, wherein the plurality of recesses cover between 30% and 60% of the front surface.

[0143] Item 7: The golf club head of item 1, wherein the plurality of recesses cover between 60% and 100% of the front surface.

[0144] Item 8: The occupied area is 500 μm 2 to 100,000 μm 2Item 1. The golf club head according to item 1, wherein

[0145] Item 9: Any of the plurality of recesses is spaced from an adjacent recess by 1 μm to 250 μm (approximately 3.9 × 10 -5 Item 1. The golf club head of item 1, wherein the golf club heads are spaced apart by a separation distance of between 0.0098 inches and about 0.0098 inches.

[0146] Item 10: The golf club head of item 1, wherein the plurality of recesses increase golf ball spin rate by 5% to 30% under wet conditions.

[0147] Item 11: The golf club head according to item 1, wherein the plurality of recesses increase the launch angle by 1 to 3 degrees under wet conditions.

[0148] Item 12: A golf club head, comprising: a body having a heel end and a toe end; a striking face having a geometric center, the striking face having a front surface, the front surface having a recess array having a plurality of rows of recesses aligned parallel to an array axis, each recess having a center point, one or more side walls, and a bottom surface, each recess having a footprint measured as the area enclosed by the side walls in a plane coincident with the front surface, the footprint being less than 0.01 μm 2 to 250,000 μm 2 and each recess has a maximum depth, measured perpendicular to the front surface from the bottom surface to a plane coincident with the front surface, the maximum depth being between 0.1 μm and 15 μm, and each recess has a width, measured parallel to the array axis through the center point of the recess, the width being between 0.1 μm and 500 μm.

[0149] Item 13: The golf club head of Item 12, wherein the golf club head further has a horizontal reference axis extending from the heel end to the toe end through the geometric center of the striking face, and the recess array is angled so that the array axis intersects the horizontal reference axis at an angle of plus or minus 0 degrees to 90 degrees.

[0150] Item 14: The golf club head of item 13, wherein the recessed array is angled so that the array axis intersects the horizontal reference axis at an angle selected from the group consisting of plus or minus 10 degrees, plus or minus 20 degrees, plus or minus 30 degrees, plus or minus 40 degrees, plus or minus 45 degrees, plus or minus 50 degrees, plus or minus 60 degrees, plus or minus 70 degrees, plus or minus 80 degrees, and 90 degrees.

[0151] Item 15: The golf club head of item 12, wherein the golf club head further has a horizontal reference axis, a low region, and a high region, the horizontal reference axis extending from the heel end to the toe end through the geometric center of the striking face, the low region being below the horizontal reference axis, the high region being above the horizontal reference axis, and a majority of the recess array being located within the low region.

[0152] Item 16: The golf club head of item 12, wherein the coefficient of friction between the front surface and a urethane-coated golf ball is between 0.05 and 0.95.

[0153] Item 17: The golf club head of item 12, wherein the recess array has an array length measured in a direction from the heel end to the toe end, and the array length is between 1.5 inches and 2.5 inches.

[0154] Item 18: A golf club head comprising: a body; and a striking face, the striking face having a front surface; a recess array having a plurality of rows of recesses aligned parallel to an array axis, each recess having a center point, one or more sidewalls, and a bottom surface; each recess having a footprint measured as the area enclosed by the sidewalls in a plane coincident with the front surface; 2 to 250,000 μm 2 wherein each recess has a maximum depth measured perpendicular to the front surface from the bottom surface to a plane coincident with the front surface, each recess has a width measured parallel to the array axis through the center point of the recess, and each recess has an aspect ratio equal to the maximum depth divided by the width, wherein the aspect ratio is between 3 and 150.

[0155] Item 19: The golf club head according to item 18, wherein the aspect ratio is between 75 and 125.

[0156] Item 20: The golf club head according to item 18, wherein the aspect ratio is between 50 and 100.

Claims

1. A golf club head, a body having a heel end and a toe end; a striking face having a geometric center; It is equipped with the striking face having a front surface; the front surface includes a plurality of recesses; each recess of the plurality of recesses having a center point, one or more sidewalls, and a bottom surface; the bottom surface has a non-uniform profile including ridges and valleys; each recess having an occupied area measured as the area enclosed by the sidewalls in a plane coincident with the front surface; The occupied area is 0.01 μm ２ to 250,000 μm ２ Between each recess having a maximum depth measured perpendicular to the front surface from the bottom surface to a plane coincident with the front surface; the maximum depth is between 0.1 μm and 15 μm; each recess having a width measured in a heel-to-toe direction through the center point of the recess; the width is between 0.1 μm and 500 μm; each recess has an aspect ratio equal to said maximum depth divided by said width; the aspect ratio is between 6 and 150; Golf club head.

2. each recess having a height measured in a sole-to-top rail direction through the center point of the recess; the height is between 0.1 μm and 500 μm; The golf club head according to claim 1 .

3. 3. The golf club head of claim 1, wherein the coefficient of friction between the front surface and a urethane coated golf ball is between 0.05 and 0.

95.

4. 4. The golf club head according to claim 1, wherein the occupied area of ​​each recess has a shape selected from the group consisting of a square shape, a triangular shape, a rectangular shape, a circular shape, and a hexagonal shape.

5. 5. The golf club head of claim 1, wherein the one or more side walls include a number of side walls selected from the group consisting of one side wall, two side walls, three side walls, four side walls, five side walls, six side walls, seven side walls, eight side walls, nine side walls, and ten side walls.

6. The golf club head of any one of claims 1 to 5, wherein the plurality of recesses cover between 30% and 60% of the front surface.

7. The golf club head of any one of claims 1 to 5, wherein the plurality of recesses cover between 60% and 100% of the front surface.

8. The occupied area is 500 μm ２ to 100,000 μm ２ The golf club head according to any one of claims 1 to 7, wherein the thickness is between 100 and 120 mm.

9. Any of the plurality of recesses is spaced from an adjacent recess by 1 μm to 250 μm (approximately 3.9×10 －５ The golf club head of any one of claims 1 to 8, wherein the first and second shafts are spaced apart by a separation distance of between 0.0098 inches and about 0.0098 inches.

10. The golf club head of any one of claims 1 to 9, wherein the plurality of recesses increase golf ball spin rate by 5% to 30% under wet conditions.

11. The golf club head of any one of claims 1 to 10, wherein the plurality of recesses reduce launch angle by between 1 and 3 degrees under wet conditions.

12. A golf club head, a body having a heel end and a toe end; a striking face having a geometric center; It is equipped with the striking face having a front surface; the front surface includes a recess array having a plurality of rows of recesses aligned parallel to an array axis; each recess having a center point, one or more sidewalls, and a bottom surface; the bottom surface has a non-uniform profile including ridges and valleys; each recess having an occupied area measured as the area enclosed by the sidewalls in a plane coincident with the front surface; The occupied area is 0.01 μm ２ to 250,000 μm ２ Between each recess having a maximum depth measured perpendicular to the front surface from the bottom surface to a plane coincident with the front surface; the maximum depth is between 0.1 μm and 15 μm; each recess having a width measured parallel to the array axis through the center point of the recess; the width is between 0.1 μm and 500 μm; each recess has an aspect ratio equal to said maximum depth divided by said width; the aspect ratio is between 6 and 150; Golf club head.

13. the golf club head further has a horizontal reference axis extending through the geometric center of the striking face from the heel end to the toe end; The golf club head of claim 12 , wherein the recess array is angled so that the array axis intersects the horizontal reference axis at an angle of plus or minus 0 to 90 degrees.

14. 14. The golf club head of claim 13, wherein the recess array is angled such that the array axis intersects the horizontal reference axis at an angle selected from the group consisting of plus or minus 10 degrees, plus or minus 20 degrees, plus or minus 30 degrees, plus or minus 40 degrees, plus or minus 45 degrees, plus or minus 50 degrees, plus or minus 60 degrees, plus or minus 70 degrees, plus or minus 80 degrees, and 90 degrees.

15. the golf club head further comprises a horizontal reference axis, a low region, and a high region; the horizontal reference axis extends from the heel end to the toe end through the geometric center of the striking face; the low region is below the horizontal reference axis; the high region is above the horizontal reference axis; a majority of the recessed array is located within the row region; The golf club head of claim 12.

16. The golf club head of any one of claims 12 to 15, wherein the coefficient of friction between the front surface and a urethane covered golf ball is between 0.05 and 0.

95.

17. the recess array has an array length measured in a direction from the heel end to the toe end; the array length is between 1.5 inches and 2.5 inches; The golf club head of claim 12.

18. A golf club head, The main body and The striking face and It is equipped with the striking face having a front surface; the front surface includes a recess array having a plurality of rows of recesses aligned parallel to an array axis; each recess having a center point, one or more sidewalls, and a bottom surface; the bottom surface has a non-uniform profile including ridges and valleys; each recess having an occupied area measured as the area enclosed by the sidewalls in a plane coincident with the front surface; The occupied area is 0.01 μm ２ to 250,000 μm ２ Between each recess having a maximum depth measured perpendicular to the front surface from the bottom surface to a plane coincident with the front surface; each recess having a width measured parallel to the array axis through the center point of the recess; each recess has an aspect ratio equal to said maximum depth divided by said width; the aspect ratio is between 3 and 150; Golf club head.

19. 19. The golf club head of claim 18, wherein the aspect ratio is between 75 and 125.

20. The golf club head of claim 18 , wherein the aspect ratio is between 50 and 100.

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