HARDMETAL MATERIALS FOR HIGH-TEMPERATURE APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Application No. 60/710,016 entitled "HARDMETAL MATERIALS FOR HIGH- TEMPERATURE APPLICATIONS" and filed on August 19, 2005, which is incorporated by reference as part of the specification of this application.

Background

[0002] This application relates to hardmetal compositions, their fabrication techniques, and associated applications. [0003] Hardmetals include various composite materials and are specially designed to be hard and refractory, and exhibit strong resistance to wear. Examples of widely-used hardmetals include sintered or cemented carbides or carbonitrides, or a combination of such materials. Some hardmetals, called cermets, have compositions that may include processed ceramic particles (e.g., TiC) bonded with binder metal particles. Certain compositions of hardmetals have been documented in the technical literature. For example, a comprehensive compilation of hardmetal compositions is published in Brookes' World Dictionary and Handbook of Hardmetals, sixth edition, International Carbide Data, United Kingdom (1996) .

[0004] Hardmetals may be used in a variety of applications. Exemplary applications include cutting tools for cutting metals., stones, and other hard materials, wire-drawing dies, knives, mining tools for cutting coals and various ores and rocks, and drilling tools for oil and other drilling applications. In addition, such hardmetals also may be used to construct housing and exterior surfaces or layers for various devices to meet specific needs of the operations of the devices or the environmental conditions under which the devices operate. [0005] Many hardmetals may be formed by first dispersing hard, refractory particles of carbides or carbonitrides in a binder matrix and then pressing and sintering the mixture. The sintering process allows the binder matrix to bind the particles and to condense the mixture to form the resulting hardmetals. The hard particles primarily contribute to the hard and refractory properties of the resulting hardmetals .

Summary

[0006] The hardmetal materials described below include materials comprising hard particles having a first material, and a binder matrix having a second, different material. The hard particles are spatially dispersed in the binder matrix in a substantially uniform manner. The first material for the hard particles may include, for example, materials based on tungsten carbide, materials based on titanium carbide, materials based on a mixture of tungsten carbide and titanium carbide, other carbides, nitrides, borides, suicides, and combinations of these materials. The second material for the binder matrix may include, among others, rhenium, a mixture of rhenium and cobalt, a nickel-based superalloy, a mixture of a nickel-based superalloy and rhenium, a mixture of a nickel-based superalloy, rhenium and cobalt, and these materials mixed with other materials. Tungsten may also be used as a binder matrix material in hardmetal materials. The nickel-based superalloy may be in the γ-γ' metallurgic phase. [0007] In various implementations, for example, the volume of the second material may be from about 3% to about 40% of a total volume of the material. For some applications, the binder matrix may comprise rhenium in an amount at or greater than 25% of a total weight of the binder matrix of the final material . For other applications, the second material may include a Ni-based superalloy. The Ni-based superalloy may include Ni and other elements such as Re for certain applications.

[0008] Fabrication of the hardmetal materials of this application may be carried out by, according to one implementation, sintering the material mixture under a vacuum condition and performing a solid-phase sintering under a pressure applied through a gas medium. Such hardmetals may also be coated on surfaces using thermal spray methods to form either hardmetal coatings and hardmetal structures . [0009] Advantages arising from various implementations of the described hardmetal materials may include one or more of the following: superior hardness in general, enhanced hardness at high temperatures, and improved resistance to corrosion and oxidation. [0010] Additional material compositions and their application are disclosed. For example, a material can include hard particles

comprising at least one carbide selected from at least one of TaC, HfC, NbC, ZrC, TiC, WC, VC, Al ₄ C ₃ , ThC ₂ , Mo ₂ C, SiC and B ₄ C; and a binder matrix that binds the hard particles and comprises rhenium. For another example, a material can include hard particles comprising at least one nitride selected from at least one of HfN, TaN, BN, ZrN, and TiN; and a binder matrix that binds the hard particles and comprises rhenium. As yet another example, a material can include hard particles comprising at least one boride selected from at least one of HfB ₂ , ZrB ₂ , TaB ₂ , TiB ₂ , NbB ₂ , and WB; and a binder matrix that binds the hard particles and comprises rhenium.

These and other materials can be used to construct a jet nozzle or a non-erosive nozzle throat for various applications. [0011] These and other features, implementations, and advantages are now described in details with respect to the drawings, the detailed description, and the claims.

Drawing Description

[0012] FIG. 1 shows one exemplary fabrication flow in making a hardmetal according to one implementation. [0013] FIG. 2 shows an exemplary two-step sintering process for processing hardmetals in a solid state.

[0014] FIGS. 3, 4, 5, 6, 7, and 8 show various measured properties of selected exemplary hardmetals.

[0015] FIGS. 9 and 10 illustrate examples of the thermal spray methods . Detailed Description

[0016] Compositions of hardmetals are important in that they directly affect the technical performance of the hardmetals in their intended applications, and processing conditions and equipment used during fabrication of such hardmetals. The hardmetal compositions also can directly affect the cost of the raw materials for the hardmetals, and the costs associated with the fabrication processes. For these and other reasons, extensive efforts have been made in the hardmetal industry to develop technically superior and economically feasible compositions for hardmetals. This application describes, among other features, material compositions for hardmetals with selected binder matrix materials that, together, provide performance advantages .

[0017] Material compositions for hardmetals of interest include various hard particles and various binder matrix materials. In general, the hard particles may be formed from carbides of the metals in columns IVB (e.g., TiC, ZrC, HfC), VB (e.g., VC, NbC, TaC), and VIB (e.g., Cr ₃ C ₂ , Mo ₂ C, WC) in the Periodic Table of Elements. In addition, nitrides formed by metals elements in columns IVB (e.g., TiN, ZrN, HfN) and VB (e.g., VN, NbN, and TaN) in the Periodic Table of Elements may also be used. For example, one material composition for hard particles that is widely used for many hardmetals is a tungsten carbide, e.g., the mono tungsten carbide

(WC) . Various nitrides may be mixed with carbides to form the hard particles. Two or more of the above and other carbides and nitrides may be combined to form WC-based hardmetals or WC-free hardmetals. Examples of mixtures of different carbides include but are not limited to a mixture of WC and TiC, and a mixture of WC, TiC, and TaC. In addition to various carbides, nitrides, carbonitrides, borides, and suicides may also be used as hard particles for hardmetals. Examples of various suitable hard particles are described in this application. [0018] The material composition of the binder matrix, in addition to providing a matrix for bonding the hard particles together, can significantly affect the hard and refractory properties of the resulting hardmetals. In general, the binder matrix may include one or more transition metals in the eighth column of the Periodic Table of Elements, such as cobalt (Co) , nickel (Ni) , and iron (Fe) , and the metals in the 6B column such as molybdenum (Mo) and chromium (Cr) . Two or more of such and other binder metals may be mixed together to form desired binder matrices for bonding suitable hard particles. Some binder matrices, for example, use combinations of Co, Ni, and Mo with different relative weights.

[0019] The hardmetal compositions described here were developed in part based on a recognition that the material composition of the binder matrix may be specially configured and tailored to provide high-performance hardmetals to meet specific needs of various applications. In particular, the material composition of the binder matrix has significant effects on other material properties of the resulting hardmetals, such as the elasticity, the rigidity, and the strength parameters (including the transverse rupture strength, the

tensile strength, and the impact strength) . Hence, the inventor recognized that it was desirable to provide the proper material composition for the binder matrix to better match the material composition of the hard particles and other components of the hardmetals in order to enhance the material properties and the performance of the resulting hardmetals.

[0020] More specifically, these hardmetal compositions use binder matrices that include rhenium, a nickel-based superalloy or a combination of at least one nickel-based superalloy and other binder materials. Other suitable binder materials may include, among others, rhenium (Re) or cobalt. A Ni-based superalloy exhibits a high material strength at a relatively high temperature . The resulting hardmetal formed with such a binder material can benefit from the high material strength at high temperatures of rhenium and KTi-superalloy and exhibit enhanced performance at high temperatures. In addition, a Ni-based superalloy also exhibits superior resistance to corrosion and oxidation, and thus, when used as a binder material, can improve the corresponding resistance of the hardmetals . [0021] The compositions of the hardmetals described in this application may include the binder matrix material from about 3% to about 40% by volume of the total materials in the hardmetals so that the corresponding volume percentage of the hard particles is about from 97% to about 60%, respectively. Within the above volume percentage range, the binder matrix material in certain implementations may be from about 4% to about 35% by volume out of the volume of the total hardmetal materials. More preferably, some compositions of the hardmetals may have from about 5% to about 30% of the binder matrix material by volume out of the volume of the total hardmetal materials. The weight percentage of the binder matrix material in the total weight of the resulting hardmetals may be derived from the specific compositions of the hardmetals. [0022] In various implementations, the binder matrices may be formed primarily by a nickel-based superalloy, and by various combinations of the nickel-based superalloy with other elements such as Re, Co, Ni, Fe, Mo, and Cr. A Ni-based superalloy of interest may comprise, in addition to Ni, elements Co, Cr, Al, Ti, Mo, W, and other elements such as Ta, Nb, B, Zr and C. For example, Ni-based

W superalloys may include the following constituent metals in weight percentage of the total weight of the superalloy: Ni from about 30% to about 70%, Cr from about 10% to about 30%, Co from about 0% to about 25%, a total of Al and Ti from about 4% to about 12%, Mo from about 0% to about 10%, W from about 0% to about 10%, Ta from about 0% to about 10%, Nb from about 0% to about 5%, and Hf from about 0% to about 5%. Ni-based superalloys may also include either or both of Re and Hf, e.g., Re from 0% to about 10%, and Hf from 0% to about 5%. Ni-based superalloy with Re may be used in applications under high temperatures. A Ni-based super alloy may further include other elements, such as B, Zr, and C, in small amounts.

[0023] Compounds TaC and NbC have similar properties to a certain extent and may be used to partially or completely substitute or replace each other in hardmetal compositions in some implementations. Either one or both of HfC and NbC also may be used to substitute or replace a part or all of TaC in hardmetal designs. Compounds WC, TiC, TaC may be produced individually and then mixed to form a mixture or may be produced in a form of a solid solution. When a mixture is used, the mixture may be selected from at least one from a group consisting of (1) a mixture of WC, TiC, and TaC,

(2) a mixture of WC, TiC, and NbC, (3) a mixture of WC, TiC, and at least one of TaC and NbC, and (4) a mixture of WC, TiC, and at least one of HfC and NbC. A solid solution of multiple carbides may exhibit better properties and performances than a mixture of several carbides. Hence, hard particles may be selected from at least one from a group consisting of (1) a solid solution of WC, TiC, and TaC, (2) a solid solution of WC, TiC, and NbC, (3) a solid solution of WC, TiC, and at least one of TaC and NbC, and (4) a solid solution of WC, TiC, and at least one of HfC and NbC. [0024] The nickel-based superalloy as a binder material may be in a γ-γ' phase where the γ' phase with a FCC structure mixes with the γ phase. The strength increases with temperature within a certain extent . Another desirable property of such a Ni-based superalloy is its high resistance to oxidation and corrosion. The nickel-based superalloy may be used to either partially or entirely replace Co in various Co-based binder compositions. As demonstrated by examples disclosed in this application, the inclusion of both of rhenium and a nickel-based superalloy in a binder matrix of a hardmetal can

W significantly improve the performance of the resulting hardmetal by- benefiting from the superior performance at high temperatures from presence of Re while utilizing the relatively low-sintering temperature of the Wi-based superalloy to maintain a reasonably low sintering temperature for ease of fabrication. In addition, the relatively low content of Re in such binder compositions allows for reduced cost of the binder materials so that such materials be economically feasible. [0025] Such a nickel-based superalloy may have a percentage weight from several percent to 100% with respect to the total weight of all material components in the binder matrix based on the specific composition of the binder matrix. A typical nickel-based superalloy may primarily comprise nickel and other metal components in a γ-γ' phase strengthened state so that it exhibits an enhanced strength which increases as temperature rises.

[0026] Various nickel-based superalloys may have a melting point lower than the common binder material cobalt, such as alloys under the trade names Rene-95, Udimet-700, Udimet-720 from Special Metals which comprise primarily Ni in combination with Co, Cr, Al, Ti, Mo, Nb, W, B, and Zr. Hence, using such a nickel-based superalloy alone as a binder material may not increase the melting point of the resulting hardmetals in comparison with hardmetals using binders with Co. [0027] However, in one implementation, the nickel-based superalloy can be used in the binder to provide a high material strength and to improve the material hardness of the resulting hardmetals, at high temperatures near or above 500° C. Tests of some fabricated samples have demonstrated that the material hardness and strength for hardmetals with a Ni-based superalloy in the binder can improve significantly, e.g., by at least 10%, at low operating temperatures in comparison with similar material compositions without Ni-based superalloy in the binder. The following table show measured hardness parameters of samples P65 and P46A with Ni-based superalloy in the binder in comparison with samples P49 and P47A with pure Co as the binder, where the compositions of the samples are listed in Table 4.

Effects of Ni-based Superalloy (NS) in Binder

[0028] Notably, at high operating temperatures above 500 ⁰ C, hardmetal samples with Ni-based superalloy in the binder can exhibit a material hardness that is significantly higher than that of similar hardmetal samples without having a Ni-based superalloy in the binder. In addition, Ni-based superalloy as a binder material can also improve the resistance to corrosion of the resulting hardmetals or cermets in comparison with hardmetals or cermets using the conventional cobalt as the binder.

[0029] A nickel-based superalloy may be used alone or in combination with other elements to form a desired binder matrix. Other elements that may be combined with the nickel-based superalloy to form a binder matrix include but are not limited to, another nickel-based superalloy, other non-nickel-based alloys, Re, Co, Ni, Fe, Mo, and Cr.

[0030] Rhenium as a binder material may be used to provide strong bonding of hard particles and in particular can produce a high melting point for the resulting hardmetal material. The melting point of rhenium is about 3180° C, much higher than the melting point of 1495° C of the commonly-used cobalt as a binder material. This feature of rhenium partially contributes to the enhanced performance of hardmetals with binders using Re, e.g., the enhanced hardness and strength of the resulting hardmetals at high temperatures. Re also has other desired properties as a binder material. For example, the hardness, the transverse rapture strength, the fracture toughness,

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and the melting point of the hardmetals with Re in their binder matrices can be increased significantly in comparison with similar hardmetals without Re in the binder matrices. A hardness Hv over 2600 Kg/mm ² has been achieved in exemplary WC-based hardmetals with Re in the binder matrices. The melting point of some exemplary WC- based hardmetals, i.e., the sintering temperature, has shown to be greater than 2200° C. In comparison, the sintering temperature for WC-based hardmetals with Co in the binders in Table 2.1 in the cited Brookes is below 1500° C. A hardmetal with a high sintering temperature allows the material to operate at a high temperature below the sintering temperature. For example, tools based on such Re-containing hardmetal materials may operate at high speeds to reduce the processing time and the overall throughput of the processing. [0031] The use of Re as a binder material in hardmetals, however, may present limitations in practice. For example, the desirable high-temperature property of Re generally leads to a high sintering temperature for fabrication. Thus, the oven or furnace for the conventional sintering process needs to operate at or above the high sintering temperature. Ovens or furnaces capable of operating at such high temperatures, e.g., above 2200° C, can be expensive and may not be widely available for commercial use. U. S. Patent No. 5,476,531 discloses a use of a rapid omnidirectional compaction (ROC) method to reduce the processing temperature in manufacturing WC-based hardmetals with pure Re as the binder material from 6% to 18% of the total weight of each hardmetal. This ROC process, however, is still expensive and is generally not suitable for commercial fabrication. [0032] One potential advantage of the hardmetal compositions and the composition methods described here is that they may provide or allow for a more practical fabrication process for fabricating hardmetals with either Re or mixtures of Re with other binder materials in the binder matrices. In particular, this two-step process makes it possible to fabricate hardmetals where Re is at or more than 25% of the total weight of the binder matrix of the resulting hardmetal. Such hardmetals with Re at or more than 25% may be used to achieve a high hardness and a high material strength at high temperatures .

W

[0033] Another limitation of using pure Re as a binder material for hardmetals is that Re oxidizes severely in air at or above about 35O ⁰ C. This poor oxidation resistance may dramatically reduce the use of pure Re as binder for any application above about 300 ⁰ C. Since Ni-based superalloy has exceptionally strength and oxidation resistance under 1000 "C, a mixture of a Ni-based superalloy and Re where Re is the dominant material in the binder may be used to improve the strength and oxidation resistance of the resulting hardmetal using such a mixture as the binder. On the other hand, the addition of Re into a binder primarily comprised of a Ni-based superalloy can increase the melting range of the resulting hardmetal, and improve the high temperature strength and creep resistance of the Ni-based superalloy binder. [0034] In general, the percentage weight of the rhenium in the binder matrix should be between a several percent to essentially 100% of the total weight of the binder matrix in a hardmetal. Preferably, the percentage weight of rhenium in the binder matrix should be at or above 5%. In particular, the percentage weight of rhenium in the binder matrix may be at or above 10% of the binder matrix. In some implementations, the percentage weight of rhenium in the binder matrix may be at or above 25% of the total weight of the binder matrix of the resulting hardmetal. Hardmetals with such a high concentration of Re may be fabricated at relatively low temperatures with a two-step process described in this application. [0035] Since rhenium is generally more expensive than other materials used in hardmetals, cost should be considered in designing binder matrices that include rhenium. Some of the examples given below reflect this consideration. In general, according to one implementation, a hardmetal composition includes dispersed hard particles having a first material, and a binder matrix having a second, different material that includes rhenium, where the hard particles are spatially dispersed in the binder matrix in a substantially uniform manner. The binder matrix may be a mixture of Re and other binder materials to reduce the total content of Re to in part reduce the overall cost of the raw materials and in part to explore the presence of other binder materials to enhance the performance of the binder matrix. Examples of binder matrices having mixtures of Re and other binder materials include, mixtures

of Re and at least one Ni-based superalloy, mixtures of Re, Co and at least one Ni.-based superalloy, mixtures of Re and Co, and others. [0036] TABLE 1 lists some examples of hardmetal compositions of interest. In this table, WC-based compositions are referred to as "hardmetals" and the TiC-based compositions are referred to as

"cermets." Traditionally, TiC particles bound by a mixture of KTi and Mo or a mixture of Ni and Mo ₂ C are cermets. Cermets as described here further include hard particles formed by mixtures of TiC and TiN, of TiC, TiN, WC, TaC, and NbC with the binder matrices formed by the mixture of Ni and Mo or the mixture of Ni and Mo ₂ C. For each hardmetal composition, three different weight percentage ranges for the given binder material in the are listed. As an example, the binder may be a mixture of a Ni-based superalloy and cobalt, and the hard particles may a mixture of WC, TiC, TaC, and NbC. In this composition, the binder may be from about 2% to about 40% of the total weight of the hardmetal. This range may be set to from about 3% to about 35% in some applications and may be further limited to a smaller range from about 4% to about 30% in other applications .

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TABLE 1 (NS: Ni-based superalloy)

[0037] Fabrication of hardmetals with Re or a nickel-based superalloy in binder matrices may be carried out as follows. First, a powder with desired hard particles such as one or more carbides or carbonitrides is prepared. This powder may include a mixture of different carbides or a mixture of carbides and nitrides. The powder is mixed with a suitable binder matrix material that includes Re or a nickel-based superalloy. In addition, a pressing lubricant, e.g., a wax, may be added to the mixture.

[0038] The mixture of the hard particles, the binder matrix material, and the lubricant is mixed through a milling or attriting process by milling or attriting over a desired period, e.g., hours, to fully mix the materials so that each hard particle is coated with the binder matrix material to facilitate the binding of the hard particles in the subsequent processes. The hard particles should also be coated with the lubricant material to lubricate the materials to facilitate the mixing process and to reduce or

eliminate oxidation of the hard particles. Next, pressing, pre- sintering, shaping, and final sintering are subsequently performed to the milled mixture to form the resulting hardmetal. The sintering process is a process for converting a powder material into a continuous mass by heating to a temperature that is below the melting temperature of the hard particles and may be performed after preliminary compacting by pressure. During this process, the binder material is densified to form a continuous binder matrix to bind hard particles therein. One or more additional coatings may be further formed on a surface of the resulting hardmetal to enhance the performance of the hardmetal. FIG. 1 is a flowchart for this implementation of the fabrication process.

[0039] In one implementation, the manufacture process for cemented carbides includes wet milling in solvent, vacuum drying, pressing, and liquid-phase sintering in vacuum. The temperature of the liquid-phase sintering is between melting point of the binder material (e.g., Co at 1495°C) and the eutectic temperature of the mixture of hardmetal (e.g., WC-Co at 1320 ⁰ C). In general, the sintering temperature of cemented carbide is in a range of 1360 to 1480 ⁰ C. For new materials with low concentration of Re or a Ni- based superalloy in binder alloy, manufacture process is same as conventional cemented carbide process. The principle of liquid phase sintering in vacuum is applied in here. The sintering temperature is slightly higher than the eutectic temperature of binder alloy and carbide. For example, the sintering condition of P17 ( 25% of Re in binder alloy, by weight ) is at 1700 ⁰ C for one hour in vacuum.

[0040] FIG. 2 shows a two-step fabrication process based on a solid-state phase sintering for fabricating various hardmetals described in this application. Examples of hardmetals that can be fabricated with this two-step sintering method include hardmetals with a high concentration of Re in the binder matrix that would otherwise require the liquid-phase sintering at high temperatures. This two-step process may be implemented at relatively low temperatures, e.g., under 2200° C, to utilize commercially feasible ovens and to produce the hardmetals at reasonably low costs. The liquid phase sintering is eliminated in this two-step process because the liquid phase sintering may not be practical due to the

generally high eutectic temperatures of the binder alloy and carbide. As discussed above, sintering at such high temperatures requires ovens operating at high temperatures which may not be commercially feasible. [0041] The first step of this two-step process is a vacuum sintering where the mixture materials for the binder matrix and the hard particles are sintered in vacuum. The mixture is initially processed by, e.g., wet milling, drying, and pressing, as performed in conventional processes for fabricating cemented carbides. This first step of sintering is performed at a temperature below the eutectic temperature of the binder alloy and the hard particle materials to remove or eliminate the interconnected porosity. The second step is a solid phase sintering at a temperature below the eutectic temperature and under a pressured condition to remove and eliminate the remaining porosities and voids left in the sintered mixture after the first step. A hot isostatic pressing (HIP) process may be used as this second step sintering. Both heat and pressure are applied to the material during the sintering to reduce the processing temperature which would otherwise be higher in absence of the pressure. A gas medium such as an inert gas may be used to apply and transmit the pressure to the sintered mixture. The pressure may be at or over 1000 bar. Application of pressure in the HIP process lowers the required processing temperature and allows for use of conventional ovens or furnaces . The temperatures of solid phase sintering and HIPping for achieving fully condensed materials are generally significantly lower than the temperatures for liquid phase sintering. For example, the sample P62 which uses pure Re as the binder may be fully densified by vacuum sintering at 2200 ⁰ C for one to two hours and then HIPping at about 2000 ⁰ C under a pressure of 30,000 PSI in the inert gas such as Ar for about one hour. Notably, the use of ultra fine hard particles with a particulate dimension less than 0.5 micron can reduce the sintering temperature for fully densifying the hardmetals (fine particles are several microns in size) . For example, in making the samples P62 and P63, the use of such ultra fine WC allows for sintering temperatures to be low, e.g., around 2000° C. This two-step process is less expensive than the ROC method and may be used to commercial production.

[0042] The following sections describe exemplary hardmetal compositions and their properties based on various binder matrix materials that include at least rhenium or a nickel-based superalloy. [0043] TABLE 2 provides a list of code names (lot numbers) for some of the constituent materials used to form the exemplary hardmetals, where Hl represents rhenium, and Ll, L2, and L3 represent three exemplary commercial nickel-based superalloys. TABLE 3 further lists compositions of the above three exemplary nickel-based superalloys, Udimet720 (U720) , Rene' 95 (R-95) , and Udimet700 (U700) , respectively. TABLE 4 lists compositions of exemplary hardmetals, both with and without rhenium or a nickel-based superalloy in the binder matrices. For example, the material composition for Lot P17 primarily includes 88 grams of T32 (WC) , 3 grams of 132 (TiC) , 3 grams of A31 (TaC), 1.5 grams of Hl (Re) and 4.5 grams of L2 (R-95) as binder, and 2 grams of a wax as lubricant. Lot P58 represents a hardmetal with a nickel-based superalloy L2 as the only binder material without Re. These hardmetals were fabricated and tested to illustrate the effects of either or both of rhenium and a nickel- based superalloy as binder materials on various properties of the resulting hardmetals. TABLES 5-8 further provide summary information of compositions and properties of different sample lots as defined above . [0044] FIGS. 3 through 8 show measurements of selected hardmetal samples of this application. FIGS. 3 and 4 show measured toughness and hardness parameters of some exemplary hardmetals for the steel cutting grades. FIGS. 5 and 6 show measured toughness and hardness parameters of some exemplary hardmetals for the non-ferrous cutting grades. Measurements were performed before and after the solid- phase sintering HIP process and the data suggests that the HIP process significantly improves both the toughness and the hardness of the materials. FIG. 7 shows measurements of the hardness as a function of temperature for some samples. As a comparison, FIGS. 7 and 8 also show measurements of commercial C2 and C6 carbides under the same testing conditions, where FIG. 7 shows the measured hardness and FIG. 8 shows measured change in hardness from the value at the room temperature (RT) . Clearly, the hardmetal samples based on the compositions described here outperform the commercial grade

materials in terms of the hardness at high temperatures. These results demonstrate that the superior performance of binder matrices with either or both of Re and a nickel-based superalloy as binder materials in comparison with Co-based binder matrix materials. TABLE 2

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TABLE 3

Ni Co Cr Al Ti Mo Nb W Zr B C V

R95 61 .982 8.04 13 16 3 .54 2 .53 3 .55 3.55 3 .54 0.049 0.059

U700 54 .331 17.34 15 35 4 .04 3 .65 5 .17 .028 008 .04 .019 .019 .005

U720 56 .334 15.32 16 38 3 .06 5 .04 3 .06 0.01 1 .30 .035 .015 .012 .004

TABLE 4

Lot No Composition (units in grams)

P17 Hl=1.5, 1,2=4.5, 132=3, A31=3, T32=88, Wax=2

P18 Hl=3, L2= 3, 132=3 , A31=3, T32=88, WaX= 2

P19 Hl=1.5, L3=4.5, 132=3, A31=3, T32=88, Wax=2

P20 Hl=3, L3= 3, 132=3 , A31=3, T32=88, Wax=2

P25 Hl=3.75, L2=2.25, 132=3, A31=3, T32=88 , Wax=2

P25A Hl=3.75, L2=2.25, 132=3, A31=3, T32=88 , Wax=2

P31 Hl=3.44, Bl=4.4, T32=92.16, Wax=2

P32 Hl=6.75, Bl=2.88, T32=90.37, Wax=2

P33 Hl=9.93, Bl=I.41, T32=88.66, Wax=2

P34 L2=14.47, 132=69. 44, Y31=16.09

P35 Hl=8.77, L2=10.27 , 132=65.73, Y31=15.23

P36 Hl=16.66, L2=6.50 , 132=62.4, Y31=14.56

P37 Hl=23.80, L2=3.09 , 132=59.38, Y31=13.76

P38 Kl=15.51, 132=68. 60, Y31=15.89

P39 K2=15.51, 132=68. 60, Y31=15.89

P40 Hl=7.57, L2=2.96, 132=5.32, A31=5.23, T32=78.92, Wax=2

P40A Hl=7.57, L2=2.96, 132=5.32, A31=5.23, T32=78.92, Wax=2

P41 Hl=ILl, L2=1.45, 132=5.20, A31=5.11, T32=77.14, Wax=2

P41A Hl=ILl, L2=1.45, 132=5.20, A31=5.11, T32=77.14, Wax=2

P42 Hl=9.32, L2=3.64, 132=6.55, A31=6.44, 121=0.40, R31=4.25, T32=69.40, Wax:

P43 Hl=9.04, L2=3.53, 132=6.35, A31=6.24, 121=7.39, R31=0.22, T32=67.24, Wax

P44 Hl=8.96, L2=3.50, 132=14.69, A31=6.19, T32=66.67 , Wax=2

P45 Hl=9.37, L2=3.66, 132=15.37, A31=6.47, Y31=6.51, T32=58.61, Wax=2

P46 Hl=11.40, L2=4.45 , 132=5.34, A31=5.25, T32=73.55 , Wax=2

P46A Hl=Il.40, L2=4.45 , 132=5.34, A31=5.25, T32=73.55 , Wax=2

P47 Hl=Il.35, Bl=4.88 , 132=5.32, A31=5.23, T32=73.22 , Wax=2

P47A Hl=Il.35, Bl=4.88 , 132=5.32, A31=5.23, T32=73.22 , Wax=2

P48 Hl=3.75, L2=2.25, 132=5, A31=5, T32=84 , Wax=2

P49 Hl=7.55, Bl=3.25, 132=5.31, A31=5.21, T32=78.68, Wax=2

P50 Hl=4.83, L2=1.89, 132=5.31, A31=5.22, T32=82.75, Wax=2

P51 Hl=7.15, L2=0.93, 132=5.23, A31=5.14, T32=81.55, Wax=2

P52 Bl=8, D31 =0.6, T3 .8=91.4, Wax=2

P53 Bl=8, D31 =0.6, T3 .4=91.4, Wax=2

P54 Bl=8, D31=0.6, T3 .2=91.4, Wax=2

P55 Hl=I.8, Bl=7.2, D31=0.6, T3.4=90.4, Wax=2

P56 Hl=I.8, Bl=7.2, D31=0.6, T3.2=90.4, Wax=2

P5SA Hl=I.8, Bl=7.2, D31=0.6, T3.2=90.4, Wax=2

P57 Hl=I.8, Bl=7.2, T3.2=91, Wax=2

P58 L2=7.5, D31=0.6, T3.2=91.9, Wax=2

P59 Hl=O.4, Bl=3, L2=4.5, D31=0.6, T3.2=91.5, Wax=2

PS2 Hl=14.48, 132=5.09, A31=5.00, T3.2=75.43, Wax=2

P62A Hl=14.48, 132=5.09, A31=5.00, T3.2=75.43, Wax=2

P63 Hl=12.47, L2=0.86, 132=5.15, A31=5.07, T3.2=76.45, Wax=2

P65 Hl=7.57, L2=2.96, 132=5.32, A31=5.23, T3.2=78.92, Wax=2

P65A Hl=7.57, L2=2.96, 132=5.32, A31=5.23, T3.2=78.92, Wax=2

P66 Hl=27.92, 132=4.91, A31=4.82, T3.2=62.35, Wax=2

P67 Hl=24.37, L3=1.62, 132=5.04, A31=4.95, T32=32.01, T33=32.01, Wax=2

P69 L2=7.5, D31=0.4, T3.2=92.1, Wax=2

P70 Ll=7.4, D31=0.3, T3.2=92.3, Wax=2

P71 L3=7.2, D31=0.3, T3.2=92.5, Wax=2

P72 Hl=I.8, Bl=7.2, D31=0.3, T3.2=90.7, Wax=2

P73 Hl=I.8, Bl=4.8, L2=2.7, D31=0.3, T3.2=90.4, Wax=2

P74 Hl=I.8, Bl=3, L2=4.5, D31=0.3, T3.2=90.4, Wax=2

P75 Hl=O.8, Bl=3, L2=4.5, D31=0.3, T3.2=91.4, Wax=2

P76 Hl=O.8, Bl=3, Ll=4.5, D31=0.3, T3.2=91.4, Wax=2

P77 Hl=O.8, Bl=3, L3=4.5, D31=0.3, T3.2=91.4, Wax=2

P78 Hl=O.8, Bl=4.5, Ll=3, D31=0.3, T3.2=91.4, Wax=2

P79 Hl=O.8, Bl=4.5, L3=3.1, D31=0.3, T3.2=91.3, Wax=2

[0045] Several exemplary categories of hardmetal compositions are described below to illustrate the above general designs of the various hardmetal compositions to include either of Re and Nickel- based superalloy, or both. The exemplary categories of hardmetal compositions are defined based on the compositions of the binder matrices for the resulting hardmetals or cermets. The first category uses a binder matrix having pure Re, the second category uses a binder matrix having a Re-Co alloy, the third category uses a binder matrix having a Ni-based superalloy, and the fourth category uses a binder matrix having an alloy having a Ni-based superalloy in combination with of Re with or without Co.

[0046] In general, hard and refractory particles used in hardmetals of interest may include, but are not limited to, carbides, nitrides, carbonitrides, borides, and suicides. Some examples of Carbides include WC, TiC, TaC, HfC, NbC, Mo ₂ C, Cr ₂ C ₃ , VC, ZrC, B ₄ C, and SiC. Examples of Nitrides include TiN, ZrN, HfN, VN, NbN, TaN, and BN. Examples of Carbonitrides include Ti (C,N), Ta (C,N), Nb(CN), Hf(CN), Zr(C,N), and V(C ₇ N). Examples of Borides include TiB ₂ ,

ZrB ₂ , HfB ₂ , TaB ₂ , VB ₂ , MoB ₂ , WB, and W ₂ B. In addition, examples of Suicides are TaSi ₂ , Wsi ₂ , NbSi ₂ , and MoSi ₂ . The above-identified four categories of hardmetals or cermets can also use these and other hard and refractory particles. [0047] In the first category of hardmetals based on the pure Re alloy binder matrix, the Re may be approximately from 5% to 40% by volume of all material compositions used in a hardmetal or cermet. For example, the sample with a lot No. P62 in TABLE 4 has 10% of pure Re, 70%of WC, 15% of TiC, and 5% of TaC by volume. This composition approximately corresponds to 14.48% of Re, 75.43% of WC, 5.09% of TiC and 5.0% of TaC by weight. In fabrication, the Specimen P62-4 was vacuum sintered at 2100° C for about one hour and 2158° C for about one hour. The density of this material is about 14.51g/cc, where the calculated density is 14.50 g/cc. The average hardness Hv is 2627+35 Kg/mm ² for 10 measurements taken at the room temperature under a load of 10 Kg. The measured surface fracture toughness K _sc is about 7.4 xlO ⁵ Pa-m ^1/2 estimated by Palmvist crack length at a load of 10 Kg. [0048] Another example under this category is P66 in TABLE 4. This sample has about 20% of Re, 60% of WC, 15% of TiC, and 5% of TaC by volume in composition. In the weight percentage, this sample has about 27.92% of Re, 62.35% of WC, 4.91% of TiC, and 4.82% of TaC. The Specimen P66-4 was first processed with a vacuum sintering process at about 2200° C for one hour and was then sintered in the solid-phase with a HIP process to remove porosities and voids. The density of the resulting hardmetal is about 14.40g/cc compared to the calculated density of 15.04g/cc. The average hardness Hv is about 2402±44 Kg/mm ² for 7 different measurements taken at the room temperature under a load of 10 Kg. The surface fracture toughness K _sc is about 8.1 xlθ ^s Pa-m ^1/2 . The sample P66 and other compositions described here with a high concentration of Re with a weight percentage greater than 25%, as the sole binder material or one of two or more different binder materials in the binder, may be used for various applications at high operating temperatures and may be manufactured by using the two-step process based on solid-phase sintering.

[0049] The microstructures and properties of Re bound multiples types of hard refractory particles, such as carbides, nitrides,

carbon nitrides, suicides, and borides, may provide advantages over Re-bound WC material. For example, Re bound WC-TiC-TaC may have better crater resistance in steel cutting than Re bound WC material. Another example is materials formed by refractory particles of Mo ₂ C and TiC bound in a Re binder.

[0050] For the second category with a Re-Co alloy as the binder matrix, the Re-Co alloy may be about from 5 to 40 Vol% of all material compositions used in the composition. In some implementations, the Re-to-Co ratio in the binder may vary from 0.01 to 0.99 approximately. Inclusion of Re can improve the mechanical properties of the resulting hardmetals, such as hardness, strength and toughness special at high temperature compared to Co bounded hardmetal . The higher Re content is the better high temperature properties are for most materials using such a binder matrix. [0051] The sample P31 in TABLE 4 is one example within this category with 2.5% of Re, 7.5% of Co, and 90% of WC by volume, and 3.44% of Re, 4.40% of Co and 92.12% of WC by weight. In fabrication, the Specimen P31-1 was vacuum sintered at 1725C for about one hour, slight under sintering with some porosities and voids. The density of the resulting hardmetal is about 15.16 g/cc (calculated density at 15.27 g/cc). The average hardness Hv is about 1889+18 Kg/mm ² at the room temperature under 10 Kg and the surface facture toughness K _sc is about 7.7 xlO ⁶ Pa-m ^1/2 . In addition, the Specimen P31-1 was treated with a hot isostatic press (HIP) process at about 1600C / 15Ksi for about one hour after sintering.

The HIP reduces or substantially eliminates the porosities and voids in the compound to increase the material density. After HIP, the measured density is about 15.25g/cc (calculated density at 15.27 g/cc) . The measured hardness Hv is about 1887+12 Kg/mm ² at the room temperature under 10 Kg. The surface fracture toughness K _sc is about 7.6 xlO ⁶ Pa-m ^1/2 .

[0052] Another example in this category is P32 in TABLE 4 with 5.0% of Re, 5.0% of Co, and 90% of WC in volume (6.75% of Re, 2.88% of Co and 90.38% of WC in weight) . The Specimen P32-4 was vacuum sintered at 1800C for about one hour. The measured density is about 15.58 g/cc in comparison with the calculated density at 15.57 g/cc. The measured hardness Hv is about 2065 Kg/mm ² at the room temperature under 10 Kg. The surface fracture toughness K _sc is about 5.9 xlO ⁶

Pa-m ^1/2 . The Specimen P32-4 was also HIP at 1600C / 15Ksi for about one hour after Sintering. The measured density is about 15.57g/cc (calculated density at 15.57 g/cc) . The average hardness Hv is about 2010+12 Kg/mm ² at the room temperature under 10 Kg. The surface fracture toughness K _sc is about 5.8 xlO ⁶ Pa-m ^1/2 . [0053] The third example is P33 in TABLE 4 which has 7.5% of Re, 2.5% of Co, and 90% of WC by volume and 9.93% of Re, 1.41% of Co and 88.66% of WC by weight. In fabrication, the Specimen P33-7 was vacuum sintered at 1950C for about one hour and was under sintering with porosities and voids. The measured density is about 15.38 g/cc (calculated density at 15.87 g/cc). The measured hardness Hv is about 2081 Kg/mm ² at the room temperature under a force of 10 Kg. The surface fracture toughness Ksc is about 5.6 xlO ⁶ Pa-m ^1/2 . The Specimen P33-7 was HIP at 1600C / 15Ksi for about one hour after Sintering. The measured density is about 15.82g/cc (calculated density=15.87 g/cc). The average hardness Hv is measured at about 2039+18 Kg/mm ² at the room temperature under 10 Kg. The surface fracture toughness Ksc is about 6.5 xlO ⁶ Pa-m ^1/2 .

TABLE 5 Re-Co alloy bound hardmetals

[0054] The samples P55, P56, P56A, and P57 in TABLE 4 are also examples for the category with a Re-Co alloy as the binder matrix. These samples have about 1.8% of Re, 7.2% of Co, 0.6% of VC except that P57 has no VC, and finally WC in balance. These different compositions are made to study the effects of hardtnetal grain size on Hv and Ksc. TABLE 5 lists the results.

[0055] The third category is based on binder matrices with Ni-based superalloys from 5 to 40% in volume of all materials in the resulting hardmetal. Ni-based superalloys are a family of high temperature alloys with γ' strengthening. Three different strength alloys, Rene' 95, Udimet 720, and Udimet 700 are used as examples to demonstrate the effects of the binder strength on mechanical properties of the final hardmetals. The Ni-based superalloys have a high strength specially at elevated temperatures. Also, these alloys have good environmental resistance such as resistance to corrosion and oxidation at elevated temperature. Therefore, Ni- based superalloys can be used to increase the hardness of Ni-based superalloy bound hardmetals when compared to Cobalt bound hardmetals. Notably, the tensile strengths of the Ni-based

superalloys are much stronger than the common binder material cobalt as shown by TABLE 6. This further shows that Ni-based superalloys are good binder materials for hardmetals.

[0056] One example for this category is P58 in TABLE 4 which has 7.5% of Rene'95, 0.6% of VC, and 91.9% of WC in weight and compares to cobalt bound P54 in TABLE 4 (8% of Co, 0.6% of VC, and 91.4% of WC) . The hardness of P58 is significant higher than P54 as shown in TABLE 7.

TABLE 7 Comparison of P54 and P58

[0057] The fourth category is Ni-based superalloy plus Re as binder, e.g., approximately from 5% to 40 % by volume of all materials in the resulting hardmetal or cermet. Because addition of Re increases the melting point of binder alloy of Ni-based superalloy plus Re, the processing temperature of hardmetal with Ni- based superalloy plus Re binder increases as the Re content increases. Several hardmetals with different Re concentrations are listed in TABLE 8. TABLE 9 further shows the measured properties of the hardmetals in TABLE 8.

TABLE 8 Hardmetal with a binder comprising Ni-based superalloy and Re

TABLE 9 Properties of hardmetals bound by Ni-based superalloy and

Re

[0058] Another example under the fourth category uses a Ni-based superalloy plus Re and Co as binder which is also about 5% to 40% by volume . Exemplary compositions of hardmetals bound by Ni-based superalloy plus Re and Co are list in TABLE 10 .

TABLE 10 Composition of hardmetals bound by Ni -based superalloy plus Re and Co

[0059] Measurements on selected samples have been performed to study properties of the binder matrices with Ni-based superalloys. In general, Ni-based superalloys not only exhibit excellent strengths at elevated temperatures but also possess outstanding resistances to oxidation and corrosion at high temperatures. Ni- based superalloys have complex microstructures and strengthening mechanisms. In general, the strengthening of Ni-based superalloys is primarily due to precipitation strengthening of γ-γ' and solid- solution strengthening. The measurements the selected samples demonstrate that Ni-based superalloys can be used as a high- performance binder materials for hardmetals. [0060] TABLE 11 lists compositions of selected samples by their weight percentages of the total weight of the hardmetals. The WC particles in the samples are 0.2 μm in size. TABLE 12 lists the conditions for the two-step process performed and measured densities, hardness parameters, and toughness parameters of the samples. The Palmqvist fracture toughness Ksc is calculated from

the total crack length of Palmgvist crack which is produced by the Vicker Indentor: Ksc=0.087* (Hv*W) ^1/2 . See, e.g., Warren and H. Matzke, Proceedings Of the International Conference On the Science of Hard Materials, Jackson, Wyoming, Aug 23-28, 1981. Hardness Hv and Crack Length are measured at a load of 10 Kg for 15 seconds. During each measurement, eight indentations were made on each specimen and the average value was used in computation of the listed data.

TABLE 11

TABLE 12

[0061] Among the tested samples, the sample P54 uses the conventional binder consisting of Co. The Ni-superalloy R-95 is used in the sample P58 to replace Co as the binder in the sample P54. As a result, the Hv increases from 2090 of P54 to 2246 of P58. In the sample P5S, the mixture of Re and Co is used to replace Co as binder and the corresponding Hv increases from 2090 of P54 to 2133 of P5S. The samples P72, P73, P74 have the same Re content but different amounts of Co and R95. The mixtures of Re, Co, and R95 are used in samples P73 and P74 to replace the binder having a mixture of Re and Co as the binder in the sample 72. The hardness Hv increases from 2041 (P72) to 2217 (P73) and 2223 (P74) .

TABLE 13

[0062] Measurements on selected samples have also been performed to further study properties of the binder matrices with Re in the binder matrices. TABLE 13 lists the tested samples. The WC particles with two different particle sizes of 2 μm and 0.2 μm were used. TABLE 14 lists the conditions for the two-step process performed and the measured densities, hardness parameters, and toughness parameters of the selected samples.

TABLE 14

[0063] TABLE 15 further shows measured hardness parameters under various temperatures for the selected samples, where the Knoop hardness H _k were measured under a load of 1 Kg for 15 seconds on a Nikon QM hot hardness tester and R is a ratio of H _k at an elevated testing temperature over H _k at 25°C. The hot hardness specimens of C2 and C6 carbides were prepared from inserts SNU434 which were purchased from MSC Co. (Melville, WY) .

TABLE 15

(each measured value at a given temperature is an averaged value of

3 different measurements)

[0064] Inclusion of Re in the binder matrices of the hardmetals increases the melting point of binder alloys that include Co-Re, Ni

superalloy-Re, Ni superalloy-Re-Co. For example, the melting point of the sample P63 is much higher than the temperature of 2200 ⁰ C used for the solid-phase sintering process. Hot hardness values of such hardmetals with Re in the binders (e.g., P17 to P63) are much higher than conventional Co bound hardmetals ( C2 and C6 carbides) . In particular, the above measurements reveal that an increase in the concentration of Re in the binder increases the hardness at high temperatures. Among the tested samples, the sample P62A with pure Re as the binder has the highest hardness. The sample P63 with a binder composition of 94% of Re and 6 % of the Ni-based superalloy R95 has the second highest hardness. The samples P40A(71.9%Re- 29.1%R95), P49(69.9%Re-30.1%R95) , P51 (88.5%Re-ll .5%R95) , and P50 (71.9%Re-28.1%R95) are the next group in their hardness. The sample P48 with 62.5% of Re and 37.5% of R95 in its binder has the lowest hardness at high temperatures among the tested materials in part because its Re content is the lowest.

[0065] In yet another category, a hardmetal or cermet may include TiC and TiN bonded in a binder matrix having Ni and Mo or Mo ₂ C. The binder Ni of cermet can be fully or partially replaced by Re, by Re plus Co, by Ni-based superalloy, by Re plus Ni-based superalloy, and by Re plus Co and Ni-based superalloy. Samples P38 and P39 are examples of Ni-bound cermets. The sample P34 is an example of Rene95-bound Cermet. The P35, P36, P37, and P45 are Re plus Rene95 bound cermet. Compositions of P34, 35, 36, 37, 38, 39, and 45 are listed in TABLE 16.

TABLE 16 Composition of P34 to P39

[0066] TABLES 17-29 list additional compositions with 3 exemplary composition ranges 1, 2, and 3 which may be used for different applications.

TABLE 17. Compositions that use pure Re as a binder for binding a carbide from carbides of IVb, Vb, & VIb columns of the Periodic Table or a nitride from nitrides of IVb & Vb columns

NbN NbN 60 to 97 34 to 65 to 96 39 to 70 to 95 45 to 92 89 87

Re Re 3 to 40 4 to 49 4 to 35 6 to 44 5 to 30 7 to 39 3000 to

Bound TaN 60 to 97 51 to 65 to 96 56 to 70 to 95 61 to 3200 TaN 96 94 93

TABLE 18 . Compositions that use Ni -based superalloy (NBSA) in a binder for binding a nitride from nitrides of IVb &Vb columns of the Periodic Table .

TABLE 19. Compositions that use Re and Ni-based superalloy (Re+NBSA) in a binder for binding a carbide from carbides of IVb, Vb, & VIb or a nitride from nitrides of IVb & Vb. The range of the binder is from l%Re + 99% superalloy to 99% Re + 1% superalloy.

TABLE 20. Compositions that use Re and Co (Re+Co) in a binder for binding a carbide from carbides of IVb, Vb, & VIb or a nitride from nitrides of IVb & Vb. The range of Binder is from l%Re + 99% Co to 99% Re + l%Co.

W

TaN 60 to 50.7 to 65 to 96 56 to 70 to 95 61.5 to 97 98 97.4 96.7

TABLE. 21. Compositions that use Ni-based superalloy (NBSA) and Co in a binder for binding a carbide from carbides of IVb, Vb, & VIb or a nitride from nitrides of IVb & Vb. The range of Binder is from 1%NBSA + 99% Co to 99%NBSA + l%Co.

ZrN Co 0.03 to 0.04 to 0.04 to 0.05 to 40 0.05 to 29.7 0.06 to 39.6 45 34.7 34

ZrN SO to 97 55 to 97 65 to 96 60 to 96 70 to 95 65 to 95

(NBSA+Co) NBSA 0.03 to 0.02 to 0.04 to 0.027 to 0.05 to 29.7 0.03 to 39.6 31 34.7 27 22

HfN Co 0.03 to 0.02 to 0.04 to 0.024 to 0.05 to 29.7 0.03 to 39.6 27 34.7 23 20

HfN 60 to 97 70 to 98 65 to 96 74 to 97.6 70 to 95 78 to 97

(NBSA+Co) NBSA 0.03 to 0.045 to 0.04 to 0.06 to 47 0.05 to 29.7 0.07 to 39.6 53 34.7 41

VN Co 0.03 to 0.04 to 0.04 to 0.055 to 0.05 to 29.7 0.066 to 39.6 44 34.7 40 34

VN 60 to 97 50 to 96 65 to 96 55 to 95 70 to 95 61 to 93

(NBSA+Co) NBSA 0.03 to 0.04 to 0.04 to 0.05 to 41 0.05 to 29.7 0.06 to 39.6 47 34.7 36

NbN CO 0.03 to 0.03 to 0.04 to 0.04 to 35 0.05 to 29.7 0.05 to 39.6 40 34.7 30

NbN 60 to 97 55 to 97 65 to 96 60 to 96 70 to 95 65 to 95

(Re+Co) NBSA 0.03 to 0.02 to 0.04 to 0.026 to 0.05 to 29.7 0.032 to 39.6 30 34.7 26 22

TaN Co 0.03 to 0.017 to 0.04 to 0.023 to 0.05 to 29.7 0.03 to 39.6 26 34.7 23 19

TaN 60 to 97 70 to 98 65 to 96 75 to 97.7 70 to 95 79 to 97

TABLE 22. Compositions that use Re, Ni-based superalloy (NBSA), and Co in a binder for binding a carbide from carbides of IVb, Vb, & VIb or a nitride from nitrides of IVb & Vb. The range of Binder is from 0.5%Re + 0.5% Co+ 99% superalloy to 99% Re + 0.5% Co + 0.5% Superalloy to 0.5%Re + 99% Co+ 0.5% Superalloy

TABLE 23 . Compositions that use Re for binding WC+TiC or WC+TaC or WC+TiC+TaC

Material Composition Range 1 Composition Range 2 Composition Range 3

Volume % Weight % Volume % Weight % Volume % Weight %

Re Re 3 to 40 4 to 54 4 to 35 5 to 49 5 to 30 7 to 43

- WC 40 to 96 40 to 96 43 to 94.5 44 to 94 45 to 93 48 to 93

WC+TiC TiC 1 to 48 0.3 to 21 l.ξ tc 43 0.E to 19 2 to 45 0.6 to 18

Re Re 3 to 40 4 to 48 4 to 35 5 to 42 5 to 30 7 to 37

- WC 50 to 96.5 44 to 96 55 to 95 49 to 94 60 to 93.5 55 to 92

WC+TaC TaC 0.5 to 24 0.5 to 21 1 to 22 1 to 19 1.5 tc 18 1.5 tol8

Re Re 3 to 40 4 to 48 4 to 35 5 to 43 5 to 30 7 to 38

- WC 40 to 95.5 36 to 95 45 to 93 41 to 93 50 to 90 48 to 90

WC+TiC TiC 1 to 48 0.3 to 22 2 to 45 o.e to 20 3 to 42 0.9 to 18

+TaC TaC 0.5 to 20 0.5 to 25 1 to 18 o.ε to 22 2 to 15 2 to 17

TABLE 24 . Compositions that use Ni-based superalloy (NBSA) for binding WC+TiC or WC+TaC or WC+TiC+TaC

TABLK 25. Compositions that use Re and Ni-based superalloy (NBSA) in a binder for binding WC+TiC or WC+TaC or WC+TiC+TaC

TABLE 26. Compositions that use Re and Co in a binder for binding WC+TiC or WC+TaC or WC+TiC+TaC

TABLE 27 . Compositions that use Co and Ni-based superalloy (NBSA) in a binder for binding WC+TiC or WC+TaC or WC+TiC+TaC

TABLE 28. Compositions that use Re , Ni-based superalloy (NBSA) ₇ and Co in a binder for binding WC+TiC or WC+TaC or WC+TiC+TaC . The range of Binder is from 0 . 5%Re + 99 . 5% superalloy to 99 . 5% Re + 0 . 5% Superalloy to 0 . 5%Re + 0 . 5% Superalloy+ 99% Co .

Material Composition Range 1 Composition Range 2 Composition Range 3

Volume Weight % Volume % Weight % Volume % Weight % %

(Re+Co Re 0.015 0.02 to 0.02 to 0. 027 to 0.025 to 0. 035 to NBSA) to 39.8 54 34.8 48 29.9 43

NBSA 0.015 0.008 to 0.02 to 0 01 to 0.025 to 0 13 to

_ to 39.8 29 34.8 26 29.9 24

WC+TiC Co 0 to 0 to 32 0 to 34.7 0 to 29 0 to 29.8 0 to 26 39.6

WC 40 to 40 to 98 43 to 44 to 97 45 to 93 48 to 96 96 94.5

TiC 1 to 48 0.3 to 24 1.5 to 45 0.5 to 22 2 to 42 0.6 to 21

(Re+Co Re 0.015 0.02 to 0.02 to 0. 027 to 0.025 to 0. 034 to +NBSA) to 39.8 47 34.8 42 29.9 37

NBSA 0.015 0.008 to 0.02 to 0 01 to 0.025 to 0 13 to to 39.8 26 34.8 22 29.9 18

WC+TaC Co 0 to 0 to 28 0 to 34.7 0 to 24 0 to 29.8 0 to 20 39.6

WC 50 to 45 to 98 55 to 95 50 to 97 60 to 93 55 to 95 96.5

TaC 0.5 to 0.5 to 24 1 to 20 O.< 3 to 21 2 to 18 1. 8 tol9 22

(Re+ Re 0.015 0.02 to 0.02 to 0. 027 to 0.025 to 0. 034 to NBSA to 39.8 65 34.8 58 29.9 51

NBSA 0.015 0.008 0.02 to 0 01 to 0.025 to 0 13 to to 39.8 to41 34.8 34 29.9 28

+Co) Co 0 to 0 to 44 0 to 34.7 0 to 37 0 to 29.8 0 to 31

39.6

WC 35 to 35 to 93 40 to 80 41 to 88 40 to 75 47 to83

WC+TiC 85

+TaC TiC 1 to 50 0.3 to 25 2 to 45 0.6 to 22 3 to 40 0 .9 to 18

TaC 0.5 to 0.4 to 26 1 to 22 0.8 to 24 2 to 20 1 .6 to 21 25

TABLE 29. Additional Material Samples and Their Compositions

W

[0067] The following TABLES 30-41 list exemplary cermet compositions with 3 exemplary composition ranges 1, 2, and 3 which may be used for different applications.

TABLE 30. Compositions that use Re as a binder for binding TiC+ Mo ₂ C, or TiN+ Mo ₂ C, or TiC+TiN+ Mo ₂ C, or TiC+TiN+Mo ₂ C+WC+TaC+VC+Cr ₂ C ₃

Material Composition Range 1 Composition Range 2 Composition Range 3

Volume % Weight % Volume % Weight % Volume % Weight %

Re Re 3 to 30 9.5 to 65 4 to 27 13 to 60 5 to 25 15 to 58

- TiC 43 to 97 19 to 88 48 to 92 23 to 79 51 to 90 25 to 75

TiC+Mo ₂ C Mo ₂ C 0 to 27 0 to 38 0 to 26 0 to 36 0 to 24 0 to 33

Re Re 3 to 30 9 to S3 4 to 27 12 to 58 5 to 25 15 to 56

- TiN 43 to 97 21 to 89 48 to 92 25 to 81 51 to 90 27 to 76

TiN+Mo ₂ C Mo ₂ C 0 to 27 0 to 36 0 to 26 0 to 34 0 to 24 0 to 31

Re Re 3 to 30 9 to 64 4 to 27 12 to 60 5 to 25 15 to 58

TiC 0.3 to 0.2 to 84 0 .4 to 0.3 to 79 0.5 to 0. 35 to

TiC+TiN 93.7 91.6 89.5 74

+Mo ₂ C TiN 0.3 to 0.3 to 85 0 .4 to 0.4 to 80 0.5 to 0.5 to 76 93.7 91.6 89.5

Mo ₂ C 0 to 27 0 to 36 0 to 26 0 to 34 0 to 24 0 to 31

Re Re 3 to 30 6 to 65 4 to 27 9 to 61 5 to 25 11 to 65

TiC 0.3 to 0.1 to 83 0 .4 to 0.2 to 78 0.5 to 0.3 to 74 93. 5 91.3 89.1

TiN 0.3 to 0. 15 to 0 .4 to 0.2 to 80 0.5 to 0.3 to 76

TiC+TiN 93.5 85 91.3 89.1

+Mo ₂ C Mo ₂ C 0 to 28 0 to 25 0 to 26 0 to 25 0 to 24 0 to 24

+WC+TaC WC 0.1 to 0. 15 to 0 15 to 0. 25 to 0.2 to 0. 35 to +VC+Cr ₂ C ₃ 20 39 15 32 12 28

TaC 0.1 to 0. 15 to 0 15 to 0. 25 to 0.2 to 0.3 to 22

15 30 12 25 10

VC 0 to 15 0 to 11 _L 0 to 12 0 to 10 0 to 10 0 to 9

Cr ₂ C ₃ 0 to 15 0 to 16 0 to 12 0 to 14 0 to 10 0 tol2

TABLE 31. Compositions that use Ni-based superalloy (NBSA) as a binder for binding TiC+ Mo ₂ C, or TiN+ Mo ₂ C, or TiC+TiN+ Mo ₂ C, or TiC+TiN+Mo ₂ C+WC+TaC+VC+Cr ₂ C ₃

Material Composition Range 1 Composition Range 2 Composition Range 3

Volume % Weight % Volume % Weight % Volume % Weight %

NBSA NBSA 3 to 30 4 to 41 4 to 27 5 to 37 5 to 25 6 to 34

- TiC 43 to 94 30 to 90 48 to 92 35 to 87 51 to 90 37 to 84

TiC+Mo ₂ C Mo ₂ C 3 to 27 4 to 40 4 to 26 6 to 39 5 to 24 8 to 36

NBSA NBSA 3 to 30 4 to 38 4 to 27 5 to 34 5 to 25 6 to 32

- TiN 43 to 94 32 to 91 48 to 92 37 to 88 51 to 90 40 to 85

TiN+Mo ₂ C Mo ₂ C 3 to 27 4 to 38 4 to 26 6 to 37 5 to 24 7 to 34

NBSA NBSA 3 to 30 4 to 40 4 to 27 5 to 36 5 to 25 6 to 34

TiC O .3 to 0 .2 to 0 .4 to 0.3 to 0.5 to 0.4 to

TiC+TiN 93.7 90 91.6 86 89.5 83

+MO ₂ C TiN O .3 to 0 .3 to 0 .4 to 0.4 to 0.5 to 0.5 to 93.7 91 91.6 88 89.5 85

Mo ₂ C 3 to 27 4 to 38 4 to 26 6 to 37 5 to 24 8 to 34

NBSA NBSA 3 to 30 2 to 40 4 to 27 4 to 36 5 to 25 5 to 34

TiC O .3 to 0 15 to 0 .4 to 0.2 to 0.5 to 0.3 to

_ 93.3 90 91.3 86 89.3 83

TiN O .3 to 0 25 to 0 .4 to 0.35 to 0.5 to 0.45 to

TiC+TiN 93.3 90 91.3 87 89.3 84

+Mo ₂ C Mo ₂ C 3 to 27 4 to 25 4 to 26 6 to 26 5 to 24 8 to +WC+TaC 25.5

+VC+Cr ₂ C ₃ WC O. L to 20 0 25 to 0 15 to 0.4 to 0.2 to 0.5 to 42 15 34 12 29

TaC O. L to 15 0 25 to 0 15 to 0.4 to 0.2 to 0.5 to 36 12 30 10 26

VC O to 15 0 to 14 0 to 12 0 to 12 0 to 10 0 to 10

Cr ₂ C ₃ O to 15 0 to 18 0 to 12 0 to 15 0 to 10 0 tol3

TABLE 32. Compositions that use Re and Ni-based superalloy (NBSA) in a binder for binding TiC+ Mo ₂ C, or TiN+ Mo ₂ C, or TiC+TiN+ Mo ₂ C, or TiC+TiN+Mo ₂ C+WC+TaC+VC+Cr ₂ C ₃

TABLE 33. Compositions that use Re and Ni in a binder for binding TiC+ Mo ₂ C, or TiN+ Mo ₂ C, or TiC+TiN+ Mo ₂ C, or TiC+TiN+Mo ₂ C+WC+TaC+VC+Cr ₂ C ₃

TABLK 34. Compositions that use Re and Co in a binder for binding TiC+ Mo ₂ C, or TiN+ Mo ₂ C, or TiC+TiN+ Mo ₂ C, or TiC+TiN+Mo ₂ C+WC+TaC+VC+Cr ₂ C ₃

Material Composition Range 1 Composition Range 2 Composition Range 3

Volume % Weight % Volume % Weight % Volume % Weight %

Re+Co Re 0.03 to 0.1 tc ) 64 0.04 to 0.13 to 0.05 to 0.16 to 29.7 26.73 60 24.75 57

Co 0.03 to 0.04 to 0.04 to 0.05 to 0.05 to 0.06 to

TiC+TiN 29.7 43 26.73 39 24.75 36

+Mo ₂ C TiC 0 to 94 0 to 90 0 to 92 0 to 87 0 to 90 0 to 83

TiN 0 to 94 0 to 91 0 to 92 0 to 88 0 to 90 0 to 85

Mo ₂ C 3 to 27 3 to 38 4 to 26 4 to 37 5 to 24 5 to 34

Re+Co Re 0.03 to 0.06 to 0.04 to 0.1 to 0.05 to 0.12 to 29.7 64 26.73 60 24.75 57

Co 0.03 to 0.03 to 0.04 to 0.04 to 0.05 to 0.05 to 29.7 43 26.73 39 24.75 36

TiC+TiN TiC 0.3 to 0.15 to .40 to 0.2 to 0.5 to 0.3 to +Mo ₂ C 93.5 89 91.3 85 89.1 82

+WC+TaC TiN 0.3 to 0.15 to .40 to 0.2 to 0.5 to 0.3 to +VC+Cr ₂ C ₃ 93.5 90 91.3 87 89.1 83

Mo ₂ C 3 to 28 3 to 26 4 to 26 4 to 26 5 to 24 5 to 25.5

WC 0.1 to 0.15 to 0.15 to 0.25 to 0.2 to 12 0.35 to 20 42 15 34 29

TaC 0.1 to 0.15 to 0.15 to 0.25 to 0.2 to 10 0.3 to 15 32 12 27 24

VC 0 to 15 0 to 16 0 to 12 0 to 13 0 to 10 0 to 11

Cr ₂ C ₃ 0 to 15 0 to 18 0 to 12 0 to 15 0 to 10 0 tol3

TABLE 35. Compositions that use Ni-based superalloy (NBSA) and Co in a binder for binding TiC+ Mo ₂ C, or TiN+ Mo ₂ C, or TiC+TiN+ Mo ₂ C, or TiC+TiN+Mo ₂ C+WC+TaC+VC+Cr ₂ C ₃

TABLE 36. Compositions that use Ni-based superalloy (NBSA) and Ni in a binder for binding TiC+ Mo ₂ C, or TiN+ Mo ₂ C, or TiC+TiN+ Mo ₂ C, or TiC+TiN+Mo ₂ C+WC+TaC+VC+Cr ₂ C ₃

W 2

TABLE 37 . Compositions that use Re, Co, and Ni-based superalloy (NBSA) in a binder for binding TiC and Mo ₂ C, or TiN and Mo ₂ C, or TiC, TiN, and Mo ₂ C, or TiC, TiN, Mo ₂ C, WC, TaC, VC, and Cr ₂ C ₃

TABLK 38 . Compositions that use Re , Ni , and Ni-based superalloy (NBSA) in a binder for binding TiC+ Mo ₂ C, or TiN+ Mo ₂ C, or TiC+TiN+ Mo ₂ C, or TiC+TiN+Mo ₂ C+WC+TaC+VC+Cr ₂ C ₃

TABLE 39. Compositions that use Re, Ni, and Co in a binder for binding TiC+ Mo ₂ C, or TiN+ Mo ₂ C, or TiC+TiN+ Mo ₂ C, or TiC+TiN+Mo ₂ C+WC+TaC+VC+Cr ₂ C ₃

TABLE 40. Compositions that use Co, Ni, and Ni-based superalloy (NBSA) in a binder for binding TiC+ Mo ₂ C, or TiN+ Mo ₂ C, or TiC+TiN+ Mo ₂ C, or TiC+TiN+Mo ₂ C+WC+TaC+VC+Cr ₂ C ₃

WC 0.1 to 0.25 to 0.15 to 0.35 to 0.2 to 12 0. 5 to 29 20 42 15 35

TaC 0 .1 to 0 .25 to 0 .15 to 0 .35 to 0.2 to 10 0 .45 to 24 15 33 12 28

VC 0 to 15 0 to 16 0 to 12 0 to 13 0 to 10 0 to 11

Cr ₂ C ₃ 0 to 15 0 to 18 0 to 12 0 to 15 0 to 10 0 to 13

TABLE 41. Compositions that use Re, Ni, Co, and Ni-based superalloy (NBSA) in a binder for binding TiC+ Mo ₂ C, or TiN+ Mo ₂ C, or TiC+TiN+ Mo ₂ C, or TiC+TiN+Mo ₂ C+WC+TaC+VC+Cr ₂ C ₃

[0068] The following TABLES 42-51 list additional examples of various compositions with 3 exemplary composition ranges 1, 2, and 3 which may be used for different applications. Similar to some compositions described above, some compositions in TABLES 42-51 may be particularly useful for applications at high temperatures as indicated in the last row under "estimated melting points."

[0069] As described above, binder matrix materials with rhenium, a nickel-based superalloy or a combination of both can enhance

material performance at high temperatures. Tungsten is typically- used as a constituent element in various hard particles such as carbides, nitrides, carbonitrides, borides, and suicides. When used as a binder matrix material, either alone or in combination with other metals, tungsten can significantly raise the melting point of the final hardmetal materials to the range of about 2500 to about 3500 ⁰ C. Hence, hardmetals using W-based binder matrix materials can be used in applications at high temperatures that may not be possible with other materials. Notably, certain compositions that use a binder matrix based on tungsten (W) shown in TABLES 43-48 show expected high melting points around 3500 ⁰ C.

[0070] For the compositions made of nitrides bound by rhenium and cobalt in TABLE 47, each nitride may be substituted by a combination of a nitride and carbide as the hard particle material . A material under this design includes hard particles comprising at least one nitride from nitrides of IVB and VB columns in the periodic table and one carbide from carbides of IVB, VB and VIB columns in the periodic table, and a binder matrix that binds the hard particles and comprises rhenium and cobalt.

TABLE 42. Re bound a Boride from Borides of IVb, Vb, & VIb or a Suicide from Suicides of IVb, Vb & VIb

Re Re 3 to 40 9.5 to 4 to 35 12.5 to 5 to 30 15 to 1800 to Bound 69.5 65 60 2200

Cr ₃ B ₂ Cr ₃ B ₂ 60 to 97 30.5 to 65 to 96 35 to 70 to 95 40 to 90.5 87.5 85

Re Re 3 to 40 7.5 to 4 to 35 10 to 5 to 30 12.5 to 2000 to Bound 64 59 54 2400

MoB ₂ MoB ₂ 60 to 97 36 to 65 to 96 41 to 70 to 95 46 to 92.5 90 87.5

Re Re 3 to 40 4 to 47 4 to 35 5 to 41 5 to 30 6.5 to 2700 to Bound 36 3000

WB WB 60 to 97 53 to 65 to 96 59 to 70 to 95 64 to 96 95 93.5

Re Re 3 to 40 4 to 47 4 to 35 5 to 41 5 to 30 6.5 to 2600 to Bound 36 2900

W ₂ B W ₂ B 60 to 91 53 to 65 to 96 59 to 70 to 95 64 to 96 95 93.5

Re Re 3 to 40 13 to 4 to 35 17 to 5 to 30 20 to 2000 to Bound 77 72 68 2400

Ti ₅ Si ₃ Ti ₅ Si ₃ 60 to 97 23 to 65 to 96 28 to 70 to 95 32 to 87 83 80

Re Re 3 to 40 10 to 4 to 35 14 to 5 to 30 17 to 2100 to Bound 72 67 62 2500

Zr ₆ Si ₅ Zr ₆ Si ₅ 60 to 97 28 to 65 to 96 33 to 70 to 95 38 to 90 86 83

Re Re 3 to 40 9 to 69 4 to 35 12 to 5 to 30 15 to 1800 to Bound 64 59 2200

WbSi ₂ NbSi ₂ 60 to 97 31 to 65 to 96 36 to 70 to 95 41 to

91 88 85

Re Re 3 to 40 7 to 62 4 to 35 9 to 57 5 to 30 12 to 2200 to Bound 51 2600

TaSi ₂ TaSi ₂ 60 to 97 38 to 65 to 96 43 to 70 to 95 49 to 93 91 88

Re Re 3 to 40 9 to 69 4 to 35 12 to 5 to 30 15 to 1800 to Bound 64 59 2200

MoSi ₂ MoSi ₂ 60 to 97 31 to 65 to 96 36 to 70 to 95 41 to 91 88 85

Re Re 3 to 40 6 to 60 4 to 35 9 to 55 5 to 30 11 to 1800 to Bound 49 2200

WSi ₂ WSi ₂ 60 to 97 40 to 65 to 96 45 to 70 to 95 51 to 94 91 89

TABLE 43 . W bound a carbide from carbides of IVb , Vb , & VIb or a nitride from nitrides of IVb & Vb .

TABLE 44. W bound a Boride from Borides of IVb, Vb, & VIb or a Suicide from Suicides of IVb, Vb & Vib

TABLE 45. Re and W (Re+W) bound a carbide from carbides of IVb, Vb, & VIb or a nitride from nitrides of IVb & Vb. The range of Binder is from l%Re + 99% W to 99% Re + 1%W.

TABLE 46 . Re and W (Re+W) bound a boride from borides of IVb , Vb, & VIb or a suicide from suicides of IVb & Vb . The range of Binder is from l%Re + 99% W to 99% Re + 1%W

TABLE 47. Re and Co (Re+Co) bound a carbide from carbides of IVb, Vb, & VIb or a nitride from nitrides of IVb & Vb. The range of Binder is from l%Re + 99% Co to 99% Re + l%Co.

TABLE 48. Re and Co (Re+Co) bound a boride from borides of IVb, Vb, & VIb or a suicide from suicides of IVb & Vb. The range of Binder is from l%Re + 99% Co to 99% Re + l%Co.

TABLE 49. Re and Mo (Re+Mo) bound a carbide from carbides of IVb, Vb, & VIb. The range of Binder is from l%Re + 99% Mo to 99% Re + l%Mo.

TABLE 50. Re and Ni (Re+Ni) bound a carbide from carbides of IVb, Vb, & VIb. The range of Binder is from l%Re + 99% Ni to 99% Re + l%Ni.

TABLE 51 . Re and Cr (Re+Cr) bound a carbide from carbides of IVb, Vb, S- VIb . The range of Binder is from l%Re + 99% Cr to 99% Re + l%Cr .

[0071] The above compositions for hardmetals or cermets may be used for a variety of applications. For example, a material as described above may be used to form a wear part in a tool that cuts, grinds, or drills a target object by using the wear part to remove the 0 material of the target object. Such a tool may include a support part made of a different material, such as a steel. The wear part

is then engaged to the support part as an insert. The tool may be designed to include multiple inserts engaged to the support part. For example, some mining drills may include multiple button bits made of a hardmetal material . Examples of such a tool includes a drill, a cutter such as a knife, a saw, a grinder, and a drill. Alternatively, hardmetals descried here may be used to form the entire head of a tool as the wear part for cutting, drilling or other machining operations. The hardmetal particles may also be used to form abrasive grits for polishing or grinding various materials. In addition, such hardmetals may also be used to construct housing and exterior surfaces or layers for various devices to meet specific needs of the operations of the devices or the environmental conditions under which the devices operate. [0072] More specifically, the hardmetals described here may be used to manufacture cutting tools for machining metals, alloys, composite materials, plastic materials, wooden materials, and others. The cutting tools may include indexable inserts for turning, milling, boring and drilling, drills, end mills, reamers, taps, hobs and milling cutters. Since the temperature of the cutting edge of such tools may be higher than 500 ⁰ C during machining, the hardmetal compositions for high-temperature operating conditions described above may have special advantages when used in such cutting tools, e.g., extended tool life and improved productivity by such tools by increasing the cutting speed. [0073] The hardmetals described here may be used to manufacture tools for wire drawing, extrusion, forging and cold heading. Also as mold and Punch for powder process. In addition, such hardmetals may be used as wear-resistant material for rock drilling and mining. [0074] The hardmetal materials described in this application may be fabricated in bulk forms or as coatings on metal surfaces. Coatings with such new hardmetal materials may be advantageously used to form a hard layer on a metal surface to achieve desired hardness that would otherwise be difficult to achieve with the underlying metal material. Bulk hardmetal materials based on the compositions in this application may be expensive and hence the use of coatings on less expensive metals with lower hardness may be used to reduce the costs of various components or parts with high hardness.

[0075] A number of powder processes for producing commercial hardmetals may be used to manufacture the hardmetals of this application. As an example, a binder alloy with Re higher than 85% in weight may be fabricated by the process of solid phase sintering to eliminate open porosities then HIP replaces liquid phase sintering.

[0076] FIG. 9 shows a flowchart for several fabrication methods for materials or structures from the above hardmetal compositions. As illustrated, alloy powders for the binders and the hard particle powders may be mixed with a milling liquid in a wet mixing process with or without a lubricant (e.g., wax). The fabrication flows on the left hand side of FIG. 9 are for fabricating hardmetals with lubricated wet mixing. The mixture is first dried by vacuum drying or spray drying process to produce lubricated grade powder. Next, the lubricated grade power is shaped into a bulky material via pill pressing, extruding, or cold isostatic press (CIP) and shaping. The CIP is a process to consolidate powder by isostatic pressure. The bulky material is then heated to remove the lubricant and is sintered in a presintering process. Next, the material may be processed via several different processes. For example, the material may be processed via a liquid phase sintering in vacuum or hydrogen and then further processed by a HIP process to form the final hardmetal parts. Alternatively, the material after the presintering may go through a solid phase sintering to eliminate open porosity and then a HIP process to form the final hardmetal parts .

[0077] When alloy powders for the binders and the hard particle powders are mixed without the lubricant, the unlubricated grade power after the drying process may be processed in two different ways to form the final hardmetal parts. The first way as illustrated simply uses hot pressing to complete the fabrication. The second way uses a thermal spray forming process to form the grade powder on a metal substrate in vacuum. Next, the metal substrate is removed to leave the structure by the thermal spray forming as a free-standing material as the final hardmetal part. In addition, the free-standing material may be further processed by a HIP process to reduce the porosities if needed.

[0078] In forming a hardmetal coating on a metal surface, a thermal spray process may be used under a vacuum condition to produce large parts coated with hardmetal materials. For example, surfaces of steel parts and tools may be coated to improve their hardness and thus performance. FIG. 10 shows an exemplary flow chart of a thermal spray process.

[0079] Various thermal spray processes are known for coating metal surfaces. For example, the ASM Handbook Vol. 7 (P408, 1998) describes the thermal spray as a family of particulate/droplet consolidation processes capable of forming metals, ceramics, intermetallics, composites, and polymers into coatings or freestanding structures. During the process, powder, wire, or rods can be injected into combustion or arc-heated jets, where they are heated, melted or softened, accelerated, and directed toward the surface, or substrate, being coated. On impact at the substrate, the particles or droplets rapidly solidify, cool, contract, and incrementally build up to form a deposit on a target surface. The thin "splats" may undergo high cooling rates, e.g., in excess of 10 ^s K/s for metals. [0080] A thermal spray process may use chemical (combustion) or electrical (plasma or arc) energy to heat feed materials injected into hot-gas jets to create a stream of molten droplets that are accelerated and directed toward the substrates being coated. Various thermal spray processes are shown in Figure 3 and 4 in ASM Handbook Vol. 7, pages 409-410.

[0081] Various details of thermal spray processes are described in "Spray Forming" by Lawley et al. and "Thermal Spray Forming of Materials" by Knight et al., which are published in ASM Handbook, Volume 7, Powder Metal Technologies and Application (1998) , from pages 396 to 407, and pages 408 to 419, respectively.

[0082] Selected hardmetal compositions described here can maintain high material strength and hardness at high temperatures at or above 1500 ⁰ C. For example, certain high-power engines operate at such high temperatures such as various jet and/or rocket engines used in various flying devices and vehicles. More specifically, jet and/or rocket nozzles, including non-erosive nozzle throats and low-erosive nozzle throats, in these and other engines may be partially or

entirely made of the selected hardmetal materials described in this application.

[0083] For example, hardmetals based on one or more of (1) one or more carbides, (2) one or more nitrides, (3) one or more borides and (4) a combination of two or more of (1) , (2) and (3) with a binder material which is either pure Re or a composite binder material with Re as one component. The melting points of various carbides, nitrides, and borides in this application are above 2400 ⁰ C. Examples of suitable carbides for the present high-temperature hardmetal materials include TaC, HfC, NbC, ZrC, TiC, WC, VC, Al ₄ C ₃ , ThC ₂ , Mo ₂ C, SiC and B ₄ C. Examples of suitable nitrides for the present high-temperature hardmetal materials include HfN, TaN, BN, ZrN, and TiN. Examples of suitable borides for the present high- temperature hardmetal materials include HfB ₂ , ZrB ₂ , TaB ₂ , TiB ₂ , NbB ₂ , and WB. Two examples of the composite binder material with Re as one component are (1) W and Re and (2) Ta and Re. [0084] While this specification contains many specifics, these should not be construed as limitations on the scope of an invention or of what may be claimed, but rather as descriptions of features specific to particular embodiments of the invention. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or a variation of a subcombination.

[0085] Only a few implementations and examples are disclosed. However, it is understood that variations and enhancements may be made.