Improved cemented carbides

Abstract

To provide improved cemented carbides.SOLUTION: A cemented carbide is provided which comprises: a hard phase comprising WC, in an amount of 87 wt.% to 91 wt.% of the total weight of the cemented carbide; a binder phase comprising Co, in an amount of 9 wt.% to 11 wt.% of the total weight of the cemented carbide; and an additive being a grain growth inhibitor containing BN, in an amount of 0.1 wt.% to 1 wt.% of the total weight of the cemented carbide. According to measurement using the ISO 28079-2009 standard, the cemented carbide has an HV30 Vickers hardness of at least 1500 HV30, and a Palmqvist fracture toughness KIc of at least 9.9 MPa√m. Further provided are a tool comprising the cemented carbide, and a method of improving galling resistance of the cemented carbide.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001]

[0001] The present invention relates to cemented carbide alloys having improved properties such as galling resistance, Vickers hardness, Palmqvist fracture toughness, and coercive force. [Background technology]

[0002]

[0002] Cemented carbides are commonly used in metallurgical products due to their hardness and fracture toughness. Generally, cemented carbides have a hard phase containing hard elements such as refractory carbides and nitrides. Cemented carbides also typically have a binder phase containing a ductile metallic binder, such as Co, Ni, or Fe. The hard phase and metallic binder phase can be processed into various microstructures that achieve different mechanical and physical properties. While different mechanical and physical properties have been achieved, such properties are generally unpredictable. Therefore, cemented carbides are continually being researched and developed in an attempt to achieve further improvements. This desire for continuous improvement is driven, at least in part, by the increasing use of hard metal alloys (e.g., Inconel alloys and other superalloys) whose applications require tools with specialized properties. In an effort to improve and resolve the problems of known cemented carbides, the inventors have discovered cemented carbides with the improved properties disclosed herein. Summary of the Invention

[0003]

[0003] In view of the above typical problems associated with conventionally known cemented carbide alloys, the present application provides a new and improved cemented carbide alloy.

[0004]

[0004] An embodiment of the present invention includes a cemented carbide comprising a hard phase comprised of WC, the cemented carbide further comprising a binder phase comprising Co, and an additive which is a grain growth inhibitor selected from the group consisting of Mo2C, TiC, TaC, and NbC, and mixtures thereof.

[0005] In one embodiment, the hard phase is 87% to 91% by weight of the cemented carbide.

[0006] In another embodiment, the binder phase is 9% to 11% by weight of the cemented carbide.

[0007] In another embodiment, the grain growth inhibitor is 0.1% to 2% by weight of the cemented carbide.

[0008]

[0008] In another embodiment, the grain growth inhibitor comprises Mo, and Mo is 0.1% to 1.50% by weight of the cemented carbide.

[0009] In another embodiment, the grain growth inhibitor is not Cr3C2, VC, or a mixture thereof.

[0010] In another embodiment, the cemented carbide has a Vickers hardness HV30 of at least 1400 HV30.

[0011] In another embodiment, the cemented carbide has a Palmqvist fracture toughness K of at least 7.5 MPa√m. Ic It has.

[0012] In another embodiment, the coercive force Hc of the cemented carbide is at least 9 kA / m.

[0013] In another embodiment, Mo ranges between about 0.40% and 0.60% by weight of the cemented carbide.

[0014] Another embodiment of the present invention includes a cemented carbide comprising a hard phase consisting of WC, the cemented carbide further comprising a binder phase comprising Co, and an additive which is a grain growth inhibitor selected from the group consisting of ZrC, BN, and mixtures thereof.

[0015] In one embodiment, the grain growth inhibitor is 0.1% to 1% by weight of the cemented carbide.

[0016]

[0016] In another embodiment, the additive further comprises a grain growth inhibitor selected from the group consisting of Mo2C, TiC, TaC, NbC, VC, Cr3C2, and mixtures thereof.

[0017] In another embodiment, the cemented carbide has a Vickers hardness HV30 of at least 1500 HV30.

[0018] In another embodiment, the cemented carbide has a Palmqvist fracture toughness K of at least 9.9 MPa√m. Ic It has.

[0019] Another embodiment of the present application includes a tool comprising the cemented carbide disclosed herein.

[0020]

[0020] Another embodiment of the present application is a method for improving galling resistance, the method comprising providing a cemented carbide specimen having a hard phase including WC, a binder phase including Co, and an additive that is a grain growth inhibitor including any of (I) Mo2C, TiC, TaC, and NbC, or (II) ZrC, BN, Mo2C, TiC, TaC, NbC, VC, and Cr3C2; and measuring the average wear of the cemented carbide specimen against Inconel 718 over sliding distances of 1 to 18 meters and 14 to 18 meters. and adjusting the amount of Mo2C in a grain growth inhibitor comprising either (I) Mo2C, TiC, TaC, and NbC, or (II) ZrC, BN, Mo2C, TiC, TaC, NbC, VC, and Cr3C2 based on the measured average coefficient of friction (COF) of the cemented carbide specimen against Inconel 718 over sliding distances of 1 to 18 meters and 14 to 18 meters to obtain the lowest possible coefficient of friction (COF) that reflects optimal galling resistance.

[0021]

[0021] In another embodiment, cemented carbide samples containing Mo2C in the range of between about 0.40 wt% and 0.60 wt% have the most optimal galling resistance.

[0022]

[0022] Other systems, features, and advantages will become apparent to one skilled in the art upon examination of the following figures and detailed description. All such additional systems, features, and advantages are intended to be included within this specification, be within the scope of the disclosure, and be protected by the following claims. Nothing in this section should be construed as limiting those claims. Further aspects and advantages are described below in conjunction with embodiments of the disclosure. It is understood that both the foregoing general description and the following detailed description of the present disclosure are examples and illustrations and are intended to provide further explanation of the claimed disclosure.

[0023] BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are included to provide a further understanding of the subject matter, are incorporated in and constitute a part of this specification, illustrate implementations of the subject matter, and together with the description, serve to explain the principles of the disclosure. [Brief explanation of the drawings]

[0024] [Figure 1]

[0024] FIG. 1 is a scanning electron microscope image of the microstructure of a particular embodiment of the cemented carbide of the present application. [Figure 2] 1 is a scanning electron microscope image of the microstructure of a particular embodiment of a cemented carbide of the present application. [Figure 3] 1 is a scanning electron microscope image of the microstructure of a particular embodiment of a cemented carbide of the present application. [Figure 4] 1 is a scanning electron microscope image of the microstructure of a particular embodiment of a cemented carbide of the present application. [Figure 5] 1 is a scanning electron microscope image of the microstructure of a particular embodiment of a cemented carbide of the present application. [Figure 6] 1 is a scanning electron microscope image of the microstructure of a particular embodiment of a cemented carbide of the present application. [Figure 7] 1 is a scanning electron microscope image of the microstructure of a particular embodiment of a cemented carbide of the present application. [Figure 8] 1 is a scanning electron microscope image of the microstructure of a particular embodiment of a cemented carbide of the present application. [Figure 9]

[0025] 1 is a scanning electron microscope image of the microstructure of a particular embodiment of a cemented carbide of the present application. [Figure 10] 1 is a scanning electron microscope image of the microstructure of a particular embodiment of a cemented carbide of the present application, showing the effect of Mo. [Figure 11] 1 is a scanning electron microscope image of the microstructure of a particular embodiment of a cemented carbide of the present application, showing the effect of Mo. [Figure 12] 1 is a scanning electron microscope image of the microstructure of a particular embodiment of a cemented carbide of the present application. [Figure 13] 1 is a scanning electron microscope image of the microstructure of a particular embodiment of a cemented carbide of the present application, showing the effect of Mo. [Figure 14] 1 is a scanning electron microscope image of the microstructure of a particular embodiment of a cemented carbide of the present application, showing the effect of Mo. [Figure 15] 1 is a scanning electron microscope image of the microstructure of a particular embodiment of a cemented carbide of the present application. [Figure 16]

[0026] 1 is a graph showing the average coefficient of friction (COF) for Inconel 718 with varying amounts of Mo. [Figure 17]

[0027] 1 is a graph illustrating the coefficient of friction (COF) for Inconel 718 in certain exemplary embodiments. [Figure 18]

[0028] 1 is a graph showing the coefficient of friction (COF) for an embodiment containing 0.47 wt. % Mo and an embodiment containing 0.1 wt. % Mo against Inconel 718. [Figure 19]

[0029] 1 is a graph showing the coefficient of friction (COF) for an embodiment containing 0.47 wt. % Mo and an embodiment containing 0.25 wt. % Mo against Inconel 718. [Figure 20]

[0030] 1 is a graph showing the coefficient of friction (COF) for an embodiment containing 0.47 wt. % Mo and an embodiment containing 0.75 wt. % Mo relative to Inconel 718. [Figure 21]

[0031] 1 is a graph showing the coefficient of friction (COF) for an embodiment containing 0.47 wt. % Mo and an embodiment containing 1 wt. % Mo against Inconel 718. [Figure 22]

[0032] 1 is a graph showing the coefficient of friction (COF) for an embodiment containing 0.47 wt. % Mo and an embodiment containing 1.25 wt. % Mo against Inconel 718. [Figure 23]

[0033] 1 is a graph showing the coefficient of friction (COF) for an embodiment containing 0.47 wt. % Mo and an embodiment containing 1.50 wt. % Mo relative to Inconel 718. [Figure 24]

[0034] 1 is a scanning electron microscope image of the microstructure of certain embodiments of the cemented carbide of the present application comprising ZrC, BN, or a mixture thereof. [Figure 25] 3 is a scanning electron microscope image of the microstructure of a particular embodiment of the cemented carbide of the present application comprising ZrC, BN, or a mixture thereof. [Figure 26] 3 is a scanning electron microscope image of the microstructure of a particular embodiment of the cemented carbide of the present application comprising ZrC, BN, or a mixture thereof. [Figure 27] 3 is a scanning electron microscope image of the microstructure of a particular embodiment of the cemented carbide of the present application comprising ZrC, BN, or a mixture thereof. [Figure 28] 1 is a scanning electron microscope image of the microstructure of certain embodiments of the cemented carbide of the present application comprising ZrC, BN, or a mixture thereof. [Figure 29]

[0035] 1 is a graph illustrating the galling resistance of certain embodiments of the cemented carbide of the present application by measuring the average coefficient of friction (COF) against a reference grade material. [Figure 30]

[0036] The grinding performance of a grade of Inconel 718 containing 0.47 wt% Mo is shown compared to the reference grade. DETAILED DESCRIPTION OF THE INVENTION

[0025]

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the presently described subject matter pertains.

[0026]

[0038] Where a range of values, e.g., a concentration range, percentage range, or ratio range, is presented, it is understood that every intervening value, to the nearest tenth of the lower limit, between the upper and lower limits of that range and any other stated or intervening value within that range is included within the described subject matter, unless the context clearly dictates otherwise. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and such embodiments are also encompassed within the described subject matter, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included within the described subject matter.

[0027]

[0039] The following definitions indicate the parameters of the subject matter being described.

[0028]

[0040] As used in this disclosure, "wt. %" refers to the given weight percent of the total weight of the cemented carbide composition, unless otherwise specified.

[0029]

[0041] As used in this disclosure, the terms "about" and "approximately" are used interchangeably. This means plus or minus 1% of the numerical value of the number being used. Thus, "about" and "approximately" are used to provide flexibility to the endpoints of numerical ranges by specifying that a particular value may be "above" or "below" the particular value. Thus, for example, a value of 50% is intended to encompass the range defined by 49.5% to 50.5%.

[0030]

[0042] As used in this disclosure, the term "predominantly" means encompassing at least 95% of a particular entity.

[0031]

[0043] As used herein, the term "substantially" refers to the complete or nearly complete extent or degree of an action, property, characteristic, state, structure, item, or result.

[0032]

[0044] As used herein, the term "lowest possible" refers to the smallest amount of value determined as the minimum value from a set of recorded values.

[0033]

[0045] As used herein, the term "optimum" refers to the most preferred, satisfactory, or desirable amount or degree.

[0034]

[0046] As used throughout this disclosure, the term "generally" has the meaning "approximately," "typically," "nearly," or "in the vicinity or range of."

[0035]

[0047] The term "Palmqvist fracture toughness," or Klc, as used in this disclosure refers to the ability of a material with a pre-crack to resist further fracture propagation upon absorbing energy.

[0036]

[0048] The term "HV30 Vickers hardness" (i.e., applying a load of 30 kgf) as used in this disclosure is a measure of resistance to localized plastic deformation, obtained by indenting a sample with a Vickers tip at 30 kgf.

[0037]

[0049] The ISO 28079-2009 standard used in this disclosure specifies a method for measuring the fracture toughness and hardness of cemented carbides, cermets, and hard alloys at room temperature by indentation. The ISO 28079-2009 standard applies to the measurement of fracture toughness and hardness, calculated using the diagonal length of the crack emanating from the indentation and Vickers hardness, and is intended for use with metal-bonded carbides and carbonitrides (e.g., cemented carbides, cermets, or hard alloys). The test procedure proposed in the ISO 28079:2009 standard is intended for use at ambient temperatures but can be extended to higher or lower temperatures by agreement. The test procedure proposed in the ISO 28079:2009 standard is also intended for use in normal laboratory air environments. It is generally not intended for use in corrosive environments such as strong acids or seawater. The ISO 28079-2009 standard is directly comparable to the ASTM B771 standard, as set forth, for example, on page 312 of the "Comprehensive Hard Materials book," 2014, Elsevier Ltd., the entire text of which is incorporated herein by reference. Thus, fracture toughness and hardness measured using the ISO 28079-2009 standard can be assumed to be the same as those measured using the ASTM B771 standard.

[0038]

[0050] The term "coercive force," or Hc, as used in this disclosure, also referred to as magnetic coercivity or magnetic coercivity, is a measure of a ferromagnetic material's ability to withstand an external magnetic field without becoming demagnetized.

[0039]

[0051] As used in this disclosure, the term "coefficient of friction," or μ, is a ratio used to quantify the frictional force that resists movement of two contacting surfaces between two objects relative to the normal force that presses and holds the two objects together.

[0040]

[0052] The term "galling," as used in this disclosure, is a form of material wear typically caused by friction and adhesion between sliding surfaces. As a material wears, portions of it are pulled along with the contacting surfaces, especially when large forces compressing the surfaces are applied. Galling is therefore caused by a combination of friction and adhesion between the surfaces, followed by sliding and tearing of the crystalline structure below the surface. This typically results in some material adhering to the adjacent surface or friction welding, but galled material may appear gouged out, with chunks of material adhering to the surface curling or tearing away.

[0041]

[0053] As used in this disclosure, the term "Inconel 718" is a common superalloy typically comprising nickel in an amount of 50.0% to 55.0% by weight, chromium in an amount of 17.0% to 21.0% by weight, molybdenum in an amount of 2.8% to 3.3% by weight, niobium and tantalum in an amount of 4.75% to 5.50% by weight, and the balance iron. Inconel 718 is also known in the art as Nicrofer 5219, Superimphy 718, Haynes 718, Pyromet 718, Supermet 718, and Udimet 718.

[0042]

[0054] Cemented carbide grades can be classified according to the grain size of the WC. The different grades are defined as nano, ultrafine, submicron, fine, medium, medium-coarse, coarse, and extra-coarse. As used in this disclosure, the terms (I) "nano grade" is defined as material having a particle size of less than about 0.2 μm, (II) "ultra-fine grade" is defined as material having a particle size of about 0.2 μm to about 0.5 μm, (III) "submicron grade" is defined as material having a particle size of about 0.5 μm to about 0.9 μm, (IV) "fine grade" is defined as material having a particle size of about 1.0 μm to about 1.3 μm, (V) "medium-coarse grade" is defined as material having a particle size of about 1.4 μm to about 2.0 μm, (VI) "medium-coarse grade" is defined as material having a particle size of about 2.1 μm to about 3.4 μm, (VII) "coarse grain" is defined as material having a particle size of about 3.5 μm to about 5.0 μm, and (VIII) "very coarse grain" is defined as material having a particle size of greater than about 5.0 μm.

[0043]

[0055] The cemented carbide of the present application is described below with reference to embodiments. The description provided herein is not intended to limit the scope of the claims, but rather to illustrate the diversity encompassed by the present application. The embodiments are described in more detail below with reference to the accompanying drawings, in which like numerals represent like elements throughout the several views and illustrate exemplary embodiments. However, claimed embodiments may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. The examples described herein are not limiting examples, but merely examples among other possible examples.

[0044] cemented carbide

[0056] The present invention relates to a cemented carbide comprising a hard phase comprising WC, a binder phase comprising a binder material such as Co, and / or additives.

[0045]

[0057] The hard phase comprises WC. In certain embodiments, the grade of WC is submicron, fine, or a mixture thereof. The cemented carbide comprises primarily WC, and WC is typically present in the cemented carbide in a range of 87% to 91% by weight based on the total weight of the cemented carbide. In some embodiments, the cemented carbide comprises primarily WC, and WC is present in the cemented carbide in a range of 87% to 91% by weight based on the total weight of the cemented carbide. In other embodiments, WC is present in the cemented carbide in a range of 89% to 91% by weight based on the total weight of the cemented carbide. In yet other embodiments, WC is present in the cemented carbide in a range of 90% to 91% by weight based on the total weight of the cemented carbide. In certain embodiments, WC is present in the cemented carbide in the ranges of 88% to 89.5%, 88% to 90%, 89% to 89.5%, 89% to 90%, 90% to 90.5%, or 90.5% to 91% by weight, all based on the total weight of the cemented carbide. The hard phase may further include additional hard phase components such as carbides, carbonitrides, and / or nitrides of Ti, Nb, V, Ta, Cr, Zr, Hf, and mixtures thereof.

[0046]

[0058] The binder phase includes a binder component, such as Co, and in certain embodiments, the binder is Co, resulting in a WC-Co hardmetal. The binder is typically present in the hardmetal in a range of 9 wt % to 11 wt %, based on the total weight of the hardmetal. In some embodiments, the binder is present in the hardmetal in a range of 9 wt % to 10 wt %, based on the total weight of the hardmetal. In other embodiments, the binder is present in the hardmetal in a range of 9.5 wt % to 11 wt %, based on the total weight of the hardmetal. In still other embodiments, the binder is present in the hardmetal in a range of 10 wt % to 11 wt %, based on the total weight of the hardmetal. In yet other embodiments, the binder is present in the hardmetal in a range of 10.5 wt % to 11 wt %, based on the total weight of the hardmetal. In still other embodiments, the binder is present in the hardmetal in a range of 10.5 wt % to 11 wt %, based on the total weight of the hardmetal. The term "approximately" is understood to mean + / - 1% of the numerical value of the figure in which it is used.

[0047]

[0059] The additive may be a grain growth inhibitor, which may be selected from the group consisting of MoC, TiC, TaC, NbC, and mixtures thereof. The grain growth inhibitor phase is typically present in the cemented carbide in a range of 0.1 wt. % to 2 wt. % based on the total weight of the cemented carbide. In some embodiments, the grain growth inhibitor phase is present in the cemented carbide in a range of 0.25 wt. % to 2 wt. % based on the total weight of the cemented carbide. In other embodiments, the grain growth inhibitor phase is present in the cemented carbide in a range of 0.5 wt. % to 2 wt. % based on the total weight of the cemented carbide. In yet other embodiments, the grain growth inhibitor phase is present in the cemented carbide in a range of 0.75 wt. % to 2 wt. % based on the total weight of the cemented carbide. In yet other embodiments, the grain growth inhibitor phase is present in the cemented carbide in a range of 1 wt. % to 2 wt. % based on the total weight of the cemented carbide. In further embodiments, the grain growth inhibitor phase is present in the cemented carbide in a range of 1.25 wt. % to 2 wt. % based on the total weight of the cemented carbide. In yet another embodiment, the grain growth inhibitor phase is present in the cemented carbide in a range of 1.50 wt.% to 2 wt.%, based on the total weight of the cemented carbide. In yet another embodiment, the grain growth inhibitor phase is present in the cemented carbide in a range of 1.75 wt.% to 2 wt.%, based on the total weight of the cemented carbide. In certain embodiments, the grain growth inhibitor phase is present in the cemented carbide in a range of 0.4 wt.% to 1 wt.%, about 0.5 wt.%, based on the total weight of the cemented carbide. The term "approximately" is understood to mean + / - 1% of the numerical value of the number with which it is used.

[0048]

[0060] In certain embodiments, the grain growth inhibitor does not include Cr3C2 and / or VC. In this regard, the cemented carbide of the present application can inhibit WC grain growth during sintering with commonly used refractory cemented carbides other than Cr3C2 and / or VC. By controlling the growth of WC grain size, excellent hardness and fracture toughness can be achieved without the addition of Cr3C2 and / or VC. In fact, the excellent hardness and fracture toughness achieved by the cemented carbide of the present application are similar to those of WC-Co cemented carbides that utilize Cr3C2 and / or VC as grain growth inhibitors. The resulting coercivity (Hc) values ​​of the cemented carbide of the present application are, for example, in the range of 9 kA / m to 16 kA / m. The corresponding coercivity Hc values ​​for WC-10Co submicron grades (i.e., 10Co refers to 10 wt. % Co in the cemented carbide composition, and the grade may contain Cr3C2 and / or VC) are typically in the range of 17 kA / m to 23 kA / m, while the coercivity Hc values ​​for WC-10Co coarse grades are typically in the range of 6 kA / m to 8.5 kA / m.

[0049]

[0061] As explained in Farag et al., "The influence of grain growth inhibitors on the microstructure and properties of submicron, ultrafine, and nano-structured hardmetals - A review, Int. J. Refract. Met. Hard Mater. 77, 12-30 (2018)" and Wittmann et al., "WC grain growth inhibition in nickel and iron binder hardmetals," Int. J. Refract. Met. Hard Mater. 20, 51-60 (2002), WC grain growth inhibition is typically achieved by adding Cr3C2 and / or VC, which are known to be more effective than other refractory carbides. However, the use of other refractory carbides and / or Fe in appropriate proportions can limit WC grain growth and produce cemented carbides with hardness and fracture toughness in the range expected when Cr3C2 is used as a grain growth inhibitor.

[0050]

[0062] In particular, the cemented carbides of the present application have a Vickers hardness HV30 of at least 1400 HV30. In certain embodiments, the cemented carbides generally have a Vickers hardness HV30 in the range of 1400 HV30 to 1700 HV30. In certain embodiments, the cemented carbides have a Vickers hardness HV30 in the range of 1400 HV30 to 1500 HV30, 1400 HV30 to 1600 HV30, 1500 HV30 to 1550 HV30, 1500 HV30 to 1600 HV30, 1500 HV30 to 1700 HV30, 1550 HV30 to 1600 HV30, 1600 HV30 to 1700 HV30, or 1650 HV30 to 1700 HV30.

[0051]

[0063] The cemented carbides of the present application typically have a Palmqvist fracture toughness K of at least 7.5 MPa√m. Ic In some embodiments, the cemented carbide has a Palmqvist fracture toughness K of 7.5 MPa√m to 12.5 MPa√m. Ic In another embodiment, the cemented carbide has a Palmqvist fracture toughness K of 8.5 MPa√m to 12.5 MPa√m. Ic In yet another embodiment, the cemented carbide has a Palmqvist fracture toughness K between 9.5 MPa√m and 12.5 MPa√m. Ic In yet another embodiment, the cemented carbide has a Palmqvist fracture toughness K of 10.5 MPa√m to 12.5 MPa√m. Ic In yet another embodiment, the cemented carbide has a Palmqvist fracture toughness K of 11.5 MPa√m to 12.5 MPa√m. Ic In certain embodiments, the cemented carbide has a Palmqvist fracture toughness K of 9 MPa√m to 11 MPa√m or 9.5 MPa√m to 10.5 MPa√m. Ic It has.

[0052]

[0064] The cemented carbide of the present invention has a coercive force, Hc, of at least 9 kA / m. In some embodiments, the cemented carbide has a coercive force, Hc, of 9 kA / m to 25 kA / m. In other embodiments, the cemented carbide has a coercive force, Hc, of 11 kA / m to 25 kA / m. In yet other embodiments, the cemented carbide has a coercive force, Hc, of 13 kA / m to 25 kA / m. In yet still other embodiments, the cemented carbide has a coercive force, Hc, of 15 kA / m to 25 kA / m. In further embodiments, the cemented carbide has a coercive force, Hc, of 17 kA / m to 25 kA / m. In yet other embodiments, the cemented carbide has a coercive force, Hc, of 19 kA / m to 25 kA / m. In specific embodiments, the cemented carbide has a coercive force, Hc, of 21 kA / m to 25 kA / m. In certain particular embodiments, the cemented carbide has a coercive force, Hc, of 12 kA / m to 20 kA / m or 17 kA / m to 20 kA / m. Coercive force is generally inversely related to the carbide microstructure; that is, as coercive force increases, the carbide grain size decreases. Therefore, a high coercive force means a small carbide grain size.

[0053]

[0065] Table 1 below lists specific embodiments of the cemented carbide of the present application, including Vickers hardness HV30, Palmqvist fracture toughness KIc, and coercivity Hc. Figures 1-8 show scanning electron microscope images of the grades listed in Table 1.

[0054]

[0066] [Table 1] TIFF2025179109000002.tif255170

[0055]

[0067] Additionally, the grain growth inhibitor phase generally comprises Mo in an amount between 0.1% and 1.50% by weight of the cemented carbide. In certain embodiments, the grain growth inhibitor phase comprises Mo in an amount between 0.1% and 1% by weight of the cemented carbide. In certain embodiments, the grain growth inhibitor phase comprises Mo in an amount between 0.25% and 1.50%, 0.50% and 1.50%, 0.75% and 1.50%, 0.90% and 1.50%, 1.00% and 1.50%, 1.10% and 1.50%, 1.25% and 1.50%, or 1.40% and 1.50% by weight of the cemented carbide.

[0056]

[0068] That is, in this embodiment, the grain growth inhibitor phase is added as MoC, and as a result, the cemented carbide contains Mo. If the amount of Mo exceeds 1.25 wt.%, precipitation of a third phase may occur. To avoid such precipitation, the upper limit of the amount of Mo in the carbide composition can be limited to 1.25 wt.% or 1 wt.%. Furthermore, in certain embodiments, the cemented carbide of the present application does not form or contain cubic Co and Mo phases.

[0057]

[0069] The presence of a third phase was experimentally verified by preparing the samples shown in Table 2 (below). Each sample contained the weight percent Mo shown in Table 2, 10% Co, and the balance WC.

[0058]

[0070] [Table 2] TIFF2025179109000003.tif73170

[0059]

[0071] Figures 9-15 show scanning electron microscope images of the microstructures of the embodiments in Table 2. The aforementioned third phase is shown in Figures 14-15, which show the microstructures for the 1.25 wt% and 1.50 wt% Mo amounts. Table 2 also shows that the presence of the third phase has an effect on the Palmqvist fracture toughness K Ic The Palmqvist fracture toughness K was significantly lower when the Mo content was 1.25 wt% compared to when the Mo content was in the range of 0.1 wt% to 1 wt%. Ic This indicates that the

[0060]

[0072] The coefficient of friction (COF) against Inconel 718 was measured for each sample listed in Table 2. The coefficient of friction (COF) was measured at sliding distances of 1 meter to 18 meters. The coefficient of friction (COF) was further measured at sliding distances of 14 to 18 meters, which showed stable behavior. The results are shown in Table 2.

[0061]

[0073] Additionally, the galling resistance of the samples in Table 2 was measured by performing a reciprocating sliding test with a constant load of 20 N over a total sliding distance of 18 meters. Figure 16 shows the results of plotting the average coefficient of friction (COF) for Inconel 718 against Mo content (wt%). The results shown in Figure 16 indicate that the galling resistance is generally good, ranging between approximately 0.40 wt% and 0.60 wt% Mo (i.e., the lowest point on the graph showing the average COF measurements over sliding distances of 1 to 18 meters in Figure 16).

[0062]

[0074] FIG. 16 plots the coefficient of friction (COF) versus sliding distance for Inconel 718 for all samples in Table 2. The COF for the 0.47 wt.% Mo embodiment is shown as the line with the lowest COF. That is, each of the other samples has a higher COF compared to the 0.47 wt.% Mo embodiment. However, galling resistance is not only a function of COF; it also considers the presence of galling events, shown as peaks and valleys on the lines in FIG. 17. As shown in FIG. 17, the samples that exhibited the most galling events were those comprised of 0.25 wt.% Mo, 1 wt.% Mo, and 1.25 wt.% Mo, respectively. For further clarity, FIGS. 19, 21, and 22 extract the lines from FIG. 17 for the 0.25 wt.% Mo, 1 wt.% Mo, and 1.25 wt.% Mo embodiments and display the lines along with the 0.47 wt.% Mo embodiment. The increase in galling events shown in FIGS. 19, 21 and 22 is consistent with the increase in average coefficient of friction (COF) shown in FIG.

[0063]

[0075] In contrast, FIG. 18 shows only the embodiment with 0.47 wt. % Mo and the embodiment with 0.1 wt. % Mo. FIG. 20 shows only the embodiment with 0.47 wt. % Mo and the embodiment with 0.75 wt. % Mo. FIG. 23 shows only the embodiment with 0.47 wt. % Mo and the embodiment with 1.50 wt. % Mo. FIGS. 18, 20, and 23 show fewer galling events (i.e., fewer peaks and valleys). Therefore, summarizing the results shown in FIGS. 16-23, it can be seen that galling resistance is generally good in the range of approximately 0.40 wt. % Mo to 0.60 wt. % Mo. The samples containing 0.1 wt% Mo, 0.75 wt% Mo, and 1.50 wt% Mo could exhibit good wear resistance against Inconel 718 with stable coefficient of friction (COF), and generally, favorable results of a satisfactorily low coefficient of friction (COF) and reduced wear events (i.e., improved wear resistance) were observed for the samples with Mo ranging between about 0.40 wt% and 0.60 wt%.

[0064]

[0076] The present application also includes a method for producing a cemented carbide. The method for producing a cemented carbide includes, first, mixing and / or grinding a hard phase and a binder phase; second, compressing the mixture of the hard phase and the binder phase; and third, sintering the compressed mixture of the hard phase and the binder phase. If necessary, the sintered product can be polished and coated to obtain a product (e.g., a tool or an insert) from the cemented carbide. The coating can be applied by chemical vapor deposition (CVD) and / or physical vapor deposition (PVD). As explained above, the cemented carbide can achieve excellent hardness and fracture toughness without the addition of Cr3C2 and / or VC as grain growth inhibitors. Furthermore, the method for producing a cemented carbide can be advanced to avoid the formation of cubic Co and Mo phases.

[0065] ZrC and / or BN

[0077] The cemented carbide of the present application may contain ZrC and / or BN as additives. The addition of ZrC or BN helps reduce metal buildup when machining Ni alloys. In this regard, metal deposition is a significant damage mechanism for cemented carbide tools when machining any metal alloy. This is usually solved by applying a coating on top of standard grades of cemented carbide. However, the cemented carbide of the present application containing ZrC and / or BN as additives may reduce the adhesion between the machined material and the bulk material if the coating is completely removed from the surface.

[0066]

[0078] When the additive is ZrC and / or BN, the ZrC and / or BN can be present in an amount of 0.1% to 0.2% by weight of the cemented carbide. Because Zr is highly reactive with oxygen and can produce highly porous materials, the addition of large amounts of ZrC (i.e., greater than 5% by weight) is avoided. Furthermore, when the additive is ZrC and / or BN, the additive may further include a grain growth inhibitor selected from the group consisting of Mo2C, TiC, TaC, NbC, VC, Cr3C2, and mixtures thereof. In other words, when the additive is ZrC and / or BN, cemented carbide can be produced with or without Cr3C2.

[0067]

[0079] Table 3 (bottom) shows the results of the Vickers hardness HV30 and Palmqvist fracture toughness K when the additives are ZrC and / or BN. Ic 24-28 show scanning electron microscope images of the grades listed in Table 3. The reference grades in Table 3 refer to 10% Co grades containing submicron WC (i.e., 10Co refers to 10% Co by weight of the cemented carbide composition).

[0068]

[0080] [Table 3] TIFF2025179109000004.tif255170

[0069]

[0081] As shown in Table 3, cemented carbides comprising ZrC and / or BN have a Vickers hardness HV30 of at least 1500 HV30. In some embodiments, the cemented carbide has a Vickers hardness HV30 ranging from 1500 HV30 to 1650 HV30. In certain embodiments, the cemented carbide has a Vickers hardness HV30 ranging from 1550 HV30 to 1650 HV30. In certain embodiments, the cemented carbide has a Vickers hardness HV30 ranging from 1600 HV30 to 1650 HV30.

[0070]

[0082] Furthermore, the cemented carbide ZrC and / or BN has a Palmqvist fracture toughness K of at least 9.9 MPa√m. Ic In certain embodiments, the cemented carbide has a Palmqvist fracture toughness K of 9.9 MPa√m to 10.6 MPa√m. Ic It has.

[0071]

[0083] The addition of ZrC is not common in cemented carbides because it is recognized as being less effective than common grain growth inhibitors. However, the addition of small amounts of ZrC can affect the interaction between the binder and the nickel alloy, thereby reducing metal buildup and improving galling resistance. The addition of small amounts of BN reduces the chemical affinity between the Co binder and the nickel alloy, thereby reducing galling resistance. In this regard, metal buildup was measured in terms of galling by observing the change in friction coefficient over time for a Ni superalloy / Inconel 718. A typical WC-Co alloy (with Cr3C2 addition) exhibits a rapid change in friction coefficient over the sliding distance, resulting in increased metal buildup. Figure 29 shows that such a rapid change was not observed for the cemented carbide grades containing ZrC and / or BN listed in Table 3. In this regard, Figure 29 shows the friction coefficient versus sliding distance curves for the reference grade and the cemented carbide grades containing ZrC and / or BN listed in Table 3. Figure 29 shows that no abrupt changes associated with galling events are observed for the cemented carbide grades containing ZrC and / or BN listed in Table 3. The addition of ZrC and / or BN reduces metal deposition but does not affect hardness and fracture toughness, which are within the range of common WC-Co materials used in machining.

[0072]

[0084] As explained above, the present application also includes a method for producing a cemented carbide. The method for producing a cemented carbide includes, first, mixing and / or grinding a hard phase and a binder phase; second, compressing the mixture of the hard phase and the binder phase; and third, sintering the compressed mixture of the hard phase and the binder phase. If necessary, the sintered product can be polished and coated to obtain a product (e.g., a tool or an insert) from the cemented carbide. The coating can be provided by chemical vapor deposition (CVD) and / or physical vapor deposition (PVD). Small amounts of ZrC and / or BN can be added to the cemented carbide. In particular, in the method for producing a cemented carbide, small amounts of ZrC and / or BN can be added to the mixture of the hard phase and the binder phase.

[0073] tool

[0085] The cemented carbide disclosed herein can be used to prepare tools. The present application relates to tools comprising the disclosed cemented carbide. For example, the tool can be, but is not limited to, an end mill, an insert, a drill, a saw tip, etc. In a specific embodiment, the tool is an end mill.

[0074]

[0086] Figure 30 shows the grinding performance of grades of Inconel 718 containing 0.47 wt% Mo compared to the reference grade. As shown in Figure 30, the average number of passes is increased by approximately 35% for grades comprised of 0.47 wt% Mo compared to the reference grade. Thus, the results shown in Figure 30 are consistent with the favorable lower coefficient of friction (COF) and reduced galling events (i.e., improved galling resistance) generally observed for samples spanning the range of Mo between about 0.40 wt% and 0.60 wt%.

[0075]

[0087] While the present disclosure has been described in connection with embodiments, those skilled in the art will appreciate that additions, deletions, modifications, and substitutions not specifically described may be made without departing from the spirit and scope of the present disclosure, as defined in the appended claims.

[0076]

[0088] With respect to the use of substantially any plural and / or singular terms herein, those skilled in the art can translate from plural to singular and / or from singular to plural as appropriate to the context and / or application. For clarity, the various permutations of singular / plural are not explicitly set forth herein.

[0077]

[0089] The subject matter described herein may depict different components contained within or connected to different other components. It should be understood that any architectures depicted are merely exemplary, and that many other architectures that achieve the same functionality may actually be implemented. Conceptually, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality is achieved. Thus, any two components combined herein to achieve a particular functionality can be considered to be "associated" with each other such that the desired functionality is achieved, regardless of the architecture or intermediate components. Similarly, any two components so associated can also be considered to be "operably connected" or "operably coupled" to each other to achieve the desired functionality, and any two components that may be so associated can also be considered to be "operably coupleable" to each other to achieve the desired functionality. Specific examples of operably coupleable include, but are not limited to, physically coupleable and / or physically interacting components, wirelessly interactable and / or wirelessly interacting components, and / or logically interacting and / or logically interacting components.

[0078]

[0090] In some cases, one or more components may be referred to herein as being "configured to," "configured by," "configurable to," "operable / operative to," "adapted / adaptable," "able to," "conformable / conformed to," etc. Those skilled in the art will understand that, unless the context requires otherwise, such terms (e.g., "configured to") can generally encompass active components and / or inactive components and / or standby components.

[0079]

[0091] While particular aspects of the inventive subject matter described herein have been shown and described, it will be apparent to one skilled in the art that, based on the teachings herein, changes and modifications can be made without departing from the subject matter described herein and its broader aspects, and therefore, the appended claims are intended to encompass within their scope all changes and modifications that are within the true spirit and scope of the subject matter described herein. In general, those skilled in the art will understand that the terms used in this specification, and particularly in the appended claims (e.g., the body of the appended claims), are generally intended to be "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.).

[0080]

[0092] Furthermore, those skilled in the art will understand that when a specific number of introduced claim recitations is intended, such intention will be explicitly stated in the claim, and that the absence of such recitation indicates no such intention. For example, to aid in understanding, the following appended claims may use the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to mean that the introduction of a claim recitation with the indefinite article "a" or "an" limits a particular claim containing such an introduced claim recitation to claims containing only one such recitation, even when the same claim contains both the introduced phrases "one or more" or "at least one" and the indefinite article "a" or "an" (e.g., "a" and / or "an" should generally be construed to mean "at least one" or "one or more"). The same applies to the use of definite articles used to introduce claim recitations.

[0081]

[0093] Furthermore, even when a particular number of introduced claims is explicitly recited, those skilled in the art will recognize that such a recitation should generally be interpreted to mean at least the recited number (e.g., the mere recitation of "two recitations" without other modifiers generally means at least two recitations, or more than two recitations).

[0082]

[0094] Furthermore, when a convention similar to "at least one of A, B, C, etc." is used, generally such a configuration is intended in the sense that one of ordinary skill in the art would understand that convention (e.g., "a system including at least one of A, B, and C" includes, but is not limited to, systems including A only, B only, C only, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). When a convention similar to "at least one of A, B, C, etc." is used, generally such a configuration is intended in the sense that one of ordinary skill in the art would understand that convention (e.g., "a system including at least one of A, B, and C" includes, but is not limited to, systems including A only, B only, C only, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). Furthermore, those skilled in the art will appreciate that whether in the description, claims, or drawings, separating words and / or phrases presenting two or more alternative terms should be understood to contemplate the inclusion of one of the terms, either term, or both terms, unless the context dictates otherwise. For example, the phrase "A or B" is typically understood to include the possibilities of "A" or "B" or "A and B."

[0083]

[0095] With respect to the appended claims, those skilled in the art will understand that the operations described therein can generally be performed in any order. Additionally, while various operational flows are depicted sequentially, it should be understood that various operations can be performed in orders other than those depicted, or can be performed simultaneously. Examples of such alternative orders include overlapping, alternating, interrupted, reordered, incremental, preliminary, supplemental, simultaneous, reverse, or other variant orders, unless the context dictates otherwise. Furthermore, terms such as "responsive to," "related to," and other past tense adjectives are not generally intended to exclude such variants, unless the context dictates otherwise.

[0084]

[0096] Those skilled in the art will appreciate that the specific exemplary processes and / or devices and / or techniques described above are representative of more general processes and / or devices and / or techniques that are taught elsewhere herein, such as in the claims appended hereto and / or elsewhere in this application.

[0085]

[0097] While various aspects and embodiments are disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are intended to be illustrative and not limiting, with the true scope and spirit being indicated by the following claims.

[0086]

[0098] The illustrative embodiments described in the detailed description, drawings, and claims are not intended to be limiting, as other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein.

[0087]

[0099] Where a range of values ​​is presented, unless the context clearly dictates otherwise, it is understood that each intervening value (to the nearest tenth of the lower limit) between the upper and lower limit of that range, and any other stated or intervening value in that presented range, is included in the disclosure. The upper and lower limits of those smaller ranges that may be independently included in the smaller ranges are also included within the disclosure, unless a specifically excluded limit is found in the stated range. When one or both limits are included in the presented range, ranges excluding either both of those included limits are also included in the disclosure.

[0088]

[0100] Those skilled in the art will appreciate that the components (e.g., operations), devices, objects, and their accompanying descriptions described herein are used as examples for conceptual clarity, and that various configuration variations are contemplated. Thus, the specific examples used herein and the accompanying descriptions are intended to be representative of a more general class. In general, the use of specific examples is intended to be representative of that class, and the absence of a particular component (e.g., operation), device, or object should not be construed as a limitation.

[0089]

[0101] Additionally, for example, the sequences and / or temporal ordering of sequences of the systems and methods described herein are illustrative and should not be construed as limiting in nature. Thus, while process steps may be shown and described in a sequential or temporal order, it should be understood that they are not necessarily limited to being performed in that particular order or sequence. For example, steps in such processes or methods may generally be performed in a variety of different sequences and orders within the scope of the present disclosure.

[0090]

[0102] Finally, the published applications and / or patents discussed herein are provided solely for their disclosure prior to the filing date of the disclosed disclosures, and nothing herein should be construed as an admission that the disclosed disclosures are not entitled to antedate such publication by virtue of prior disclosure.

Claims

1. a hard phase containing WC; a binder phase containing Co; Mo ２ an additive which is a grain growth inhibitor selected from the group consisting of C, TiC, TaC, and NbC, and mixtures thereof; Including, cemented carbide.

2. 2. The cemented carbide of claim 1, wherein the hard phase is 87% to 91% by weight of the cemented carbide.

3. 2. The cemented carbide of claim 1, wherein the binder phase is 9% to 11% by weight of the cemented carbide.

4. 2. The cemented carbide of claim 1, wherein the grain growth inhibitor is 0.1% to 2% by weight of the cemented carbide.

5. 2. The cemented carbide of claim 1, wherein the grain growth inhibitor comprises Mo, and Mo is 0.1% to 1.50% by weight of the cemented carbide.

6. The grain growth inhibitor is Cr ３ C ２ , VC, or mixtures thereof.

7. 10. The cemented carbide of claim 1, wherein the cemented carbide has a Vickers HV30 hardness of at least 1400 HV30.

8. The cemented carbide has a Palmqvist fracture toughness value K of at least 7.5 MPa√m. Ｉｃ 2. The cemented carbide of claim 1, having

9. 10. The cemented carbide of claim 1, wherein the cemented carbide has a coercive force, Hc, of at least 9 kA / m.

10. 6. The cemented carbide of claim 5, wherein Mo ranges between about 0.40% and 0.60% by weight of the cemented carbide.

11. a hard phase containing WC; a binder phase containing Co; an additive which is a grain growth inhibitor selected from the group consisting of ZrC, and BN, and mixtures thereof; Including, cemented carbide.

12. 12. The cemented carbide of claim 11, wherein the grain growth inhibitor is 0.1% to 1% by weight of the cemented carbide.

13. The additive is Mo ２ C, TiC, TaC, NbC, VC, Cr ３ C ２ 12. The cemented carbide of claim 11, further comprising a grain growth inhibitor selected from the group consisting of:

14. 12. The cemented carbide of claim 11, wherein the cemented carbide has a Vickers hardness of at least 1500 HV30.

15. The cemented carbide has a Palmqvist fracture toughness value K of at least 9.9 MPa√m. Ｉｃ 12. The cemented carbide of claim 11, having

16. A tool comprising the cemented carbide of claim 1.

17. A tool comprising the cemented carbide of claim 11.

18. A method for improving galling resistance, comprising: (I) a hard phase containing WC, a binder phase containing Co, and Mo ２ C, TiC, TaC, and NbC or (II) ZrC, BN, Mo ２ C, TiC, TaC, NbC, VC, and Cr ３ and an additive which is a grain growth inhibitor containing either C or A method comprising:

19. Measuring the average coefficient of friction (COF) of the cemented carbide samples against Inconel 718 over sliding distances of 1 to 18 meters and 14 to 18 meters; and Based on the average coefficient of friction (COF) of the cemented carbide samples against Inconel 718 measured over sliding distances of 1 to 18 meters and 14 to 18 meters, in order to obtain the lowest possible coefficient of friction (COF) that reflects the most optimal galling resistance, (I) Mo ２ C, TiC, TaC, and NbC, or (II) ZrC, BN, Mo ２ C, TiC, TaC, NbC, VC, and Cr ３ Mo in a grain growth inhibitor containing either C ２ Adjust the amount of C 20. The method of claim 18, further comprising:

20. Mo in the range of between about 0.40 wt.% and 0.60 wt.% ２ 19. The method of claim 18, wherein the cemented carbide specimen containing C has the most optimal galling resistance.

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