JP2009504926A - Cemented carbide materials for high temperature applications - Google Patents

Abstract

A hard metal composition comprising hard particles each containing a first material and a binder matrix containing a second different material comprising a rhenium or nickel based superalloy. Tungsten can also be used in the binder matrix material. Using the two-step sintering method, the cemented carbide can be produced in a solid phase at a relatively low sintering temperature, and a cemented carbide substantially completely densified can be produced. The cemented carbide coating or structure can be formed on the surface using a thermal spray process.
[Selection] Figure 2

Description

Detailed Description of the Invention

[Related applications]
This application is entitled “HARDMETAL MATERIALS FOR HIGH-TEMPERATURE APPLICATIONS” and is filed on August 19, 2005, US Provisional Application No. 60 / 710,016 (incorporated as part of the specification of this application). Claims).

[background]
The present application relates to a cemented carbide composition, a method for producing the same, and related applications.

  Cemented carbides include a variety of composite materials that are specifically designed to be hard and fire resistant and exhibit high wear resistance. Examples of cemented carbides that have been used extensively include sintered or cemented carbides or carbonitrides or combinations of such materials. Some cemented carbides, called cermets, are compositions that include processed ceramic particles (eg, TiC) bonded with binder metal particles. The specific composition of the cemented carbide is described in the technical literature. For example, the composition of cemented carbide has been extensively edited and published as "Brookes' World Dictionary and Handbook of Hardmetas, 6th edition, International Carbide Data" (UK, 1996).

  Cemented carbide can be used for various applications. Typical applications include cutting tools used to cut metals, stones and other hard materials, wire-drawing dies, knives, coal, mining tools for mining various ores and rocks, As well as drilling tools for oil and other drilling applications. Furthermore, such cemented carbides can also be used to create the housings and outer surfaces or layers of these devices that meet the specific requirements of the operation of the various devices or the environmental conditions under which they operate.

  A variety of cemented carbides can be produced by first dispersing hard or refractory particles of carbide or carbonitride in a binder matrix and then compressing and sintering the mixture. The sintering process combines the binder matrix with the particles to condense the mixture and produce a cemented carbide. The hard particles mainly contribute to the hardness and fire resistance of the resulting cemented carbide.

[Overview]
The following cemented carbide material contains a material containing hard particles comprising a first material and a binder matrix comprising a second different material. The hard particles are spread and substantially uniformly dispersed in the binder matrix. The first material for the hard particles includes, for example, a material based on tungsten carbide, a material based on titanium carbide, a mixture of tungsten carbide and titanium carbide, other carbides, nitrides, borides, silicides, And materials based on combinations of these materials. The second material for the binder matrix includes, among others, rhenium, a mixture of rhenium and cobalt, a nickel base superalloy, a mixture of nickel base superalloy and rhenium, a nickel base superalloy, a mixture of rhenium and cobalt. As well as these materials mixed with other materials. Tungsten can also be used as a binder matrix material for cemented carbide materials. The nickel-base superalloy may be of the γ-γ ′ metal phase.

  In various embodiments, for example, the volume of the second material is about 3% to 40% of the total volume of the material. For some applications, the binder matrix contains rhenium in an amount of 25% or more of the total weight of the final binder matrix. For other applications, the second material contains a nickel-based superalloy. The nickel-base superalloy contains Ni and other elements such as Re for specific applications.

  The cemented carbide material of the present application, according to one embodiment, can be produced by sintering a material mixture under reduced pressure conditions and then solid phase sintering while applying pressure through a gaseous medium. Such a cemented carbide can be further coated on the surface using a thermal spraying method to form a cemented carbide coating and a cemented carbide structure.

  The advantages arising from the various embodiments of the cemented carbide described above are generally one of excellent hardness, increased hardness at high temperatures and improved resistance to corrosion and oxidation, or Includes two or more.

Additional material compositions and their uses are disclosed. For example, the material includes 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; Mention may be made of hard particles comprising hard particles bonded and a binder matrix comprising rhenium. In another example, the material includes at least one nitride selected from at least one of HfN, TaN, BN, ZrN, and TiN; and a hard material that binds hard particles and includes a binder matrix that includes rhenium. Particles can be mentioned. In yet another example, the material includes at least one boride selected from at least one of HfB ₂ , ZrB ₂ , TaB ₂ , TiB ₂ , NbB ₂ , and WB; Mention may be made of hard particles comprising a binder matrix comprising. These and other materials can be used to make jet nozzles or non-corrosive nozzles for various applications.

  These and other features, embodiments, and advantages are described in detail through the drawings, detailed description, and claims.

[Detailed description]
The composition of the cemented carbide is important in that it directly affects the technical performance of the cemented carbide in the intended application of the cemented carbide and the processing conditions and equipment utilized during the manufacture of such cemented carbide. It is. Also, the composition of the cemented carbide may directly affect the cost of the cemented carbide raw material and the costs associated with the manufacturing process. For these and other reasons, extensive efforts have been made in the cemented carbide industry to develop technically and economically compatible compositions for cemented carbide. The present application describes, among other things, the features and material composition of cemented carbide containing selected binder matrix materials that provide performance benefits.

The subject cemented carbide material composition contains various hard particles and various binder matrix materials. In general, these hard particles are group IVB metal carbides (eg TiC, ZrC, HfC), group VB metal carbides (eg VC, NbC, TaC) and group VIB metal carbides (eg Cr ₃ C ₂ , Mo ₂ C, WC). Furthermore, nitrides manufactured with group IVB metal elements (for example, TiN, ZrN, HfN) and nitrides manufactured with group VB metal elements (for example, VN, NbN, TaN) may be used. it can. For example, one material composition of hard particles that is widely used in many cemented carbides is tungsten carbide, such as tungsten monocarbide (WC). Various types of nitrides can be mixed with carbides to produce the hard particles. Two or more of the above and other carbides and nitrides can be mixed to produce a WC-based cemented carbide or a cemented carbide containing no WC. Examples of different carbide mixtures 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 silicides can also be used as hard particles of cemented carbide. Examples of various suitable hard particles are described herein.

  In addition, the composition of the binder matrix material that provides the matrix used to bond the hard particles together significantly affects the hardness and fire resistance of the resulting cemented carbide. In general, the binder matrix comprises one or more of Group VIII transition metals of the periodic table of elements, such as cobalt (Co), nickel (Ni) and iron (Fe), and Group VIB metals such as molybdenum. (Mo) and chromium (Cr) are contained. Two or more of these and other binder metals can be mixed to produce the desired binder matrix for binding the appropriate hard particles. For example, some binder matrices utilize a mixture of Co, Ni and Mo with different relative weights.

  The cemented carbide composition described herein can be manufactured specifically for the purpose because the composition of the binder matrix material provides a high performance cemented carbide that meets the special requirements of various applications. It was developed based on recognition. In particular, the composition of the binder matrix material is relative to other material properties of the resulting cemented carbide, such as elasticity, stiffness and strength parameters (including transverse breaking strength, tensile strength and impact strength). Significantly affected. Accordingly, the inventor has found that the proper material for use in the binder matrix is better suited to the cemented carbide hard particles and other component material compositions to enhance material properties and the performance of the resulting cemented carbide. It has been found desirable to provide a composition.

  More specifically, these cemented carbide compositions use a binder matrix that includes rhenium, a nickel-based superalloy, or a mixture of at least one nickel-based superalloy and other binder materials. Other suitable binder materials include rhenium (Re) or cobalt, among others. Nickel-based superalloys exhibit high material strength at relatively high temperatures. The cemented carbide obtained by manufacturing with such a binder material benefits from the high material strength at high temperatures of rhenium and Ni superalloys, and has improved performance at high temperatures. Furthermore, nickel-base superalloys also exhibit excellent resistance to corrosion and oxidation, so that when used as a binder material, these resistances of cemented carbides are improved.

  The cemented carbide compositions described herein contain from about 3 to about 40 volume percent binder matrix material of the total cemented carbide material, so the corresponding volume percent of hard particles is from about 97% to about 60%. It is volume%. Within the above volume percent range, the binder matrix material of certain embodiments may be about 4 to about 35 volume percent of the total cemented carbide material volume. More preferably, some cemented carbide compositions contain about 5 to about 30 volume percent binder matrix material of the total cemented carbide material volume. The weight percent of the binder matrix material in the total weight of the cemented carbide produced can be derived from the specific composition of the cemented carbide.

  In various embodiments, the binder matrix can be made primarily of nickel-based superalloys and various mixtures of nickel-based superalloys with other elements such as Re, Co, Ni, Fe, Mo, and Cr. The subject nickel-base superalloy may contain elements Co, Cr, Al, Ti, Mo, W and other elements, such as Ta, Nb, B, Zr and C, in addition to Ni. For example, the nickel-base superalloy contains the following component metals in the following weight percent with respect to the total weight of the superalloy. That is, about 30% to about 70% Ni, about 10% to about 30% Cr, about 0% to about 25% Co, about 4% to about 12% Al and Ti, about 0% to Contains about 10% Mo, about 0% to about 10% W, about 0% to about 10% Ta, about 0% to about 5% Nb, and about 0% to about 5% Hf. Yes. The nickel-base superalloy may also contain Re and / or Hf, for example, about 0% to about 10% Re and 0% to about 5% Hf. Nickel-based superalloys containing Re can be used for high temperature applications. The nickel-base superalloy may further contain a small amount of other elements such as B, Zr and C.

  Since TaC and NbC have somewhat similar properties, they can be used in place of or in place of each other, partially or completely in the cemented carbide compositions of some embodiments. Also, either or both of HfC and NbC can be used to replace or replace part or all of TaC when designing cemented carbide. WC, TiC, and TaC can be manufactured in the form of a mixture of simple substances or in the form of a solid solution. When a mixture is used, the mixture is (1) a mixture of WC, TiC and TaC, (2) a mixture of WC, TiC and NbC, (3) WC, TiC and a mixture of at least one of TaC and NbC, And (4) at least one selected from the group consisting of WC, TiC and a mixture of at least one of HfC and NbC. Many types of solid carbide solutions exhibit properties and performance superior to mixtures of several types of carbides. Therefore, the hard particles are (1) a solid solution of WC, TiC and TaC, (2) a solid solution of WC, TiC and NbC, (3) a solid solution of at least one of WC, TiC and TaC and NbC, and (4) At least one can be selected from the group consisting of WC, TiC, and at least one solid solution of HfC and NbC.

  The nickel-based superalloy as the binder material may be a γ-γ 'phase in which a γ' phase having an FCC structure is mixed with a γ phase. Its strength increases to some extent as the temperature increases. Another desirable property of such nickel-based superalloys is high resistance to oxidation and corrosion. Nickel-based superalloys can be used to replace some or all of Co in various cobalt-based binder compositions. As shown in the examples disclosed herein, the presence of both rhenium and a nickel-based superalloy in the cemented carbide binder matrix can result in relatively low firing of the nickel-based superalloy. Using the sintering temperature to maintain a reasonably low sintering temperature for ease of manufacture, while taking advantage of the superior performance at high temperatures due to the presence of Re, the performance of the resulting cemented carbide is significant. To be improved. Furthermore, such materials are economical because the relatively low content of Re in such binder compositions can reduce the cost of the binder material.

  Such nickel-based superalloys are from several percent to 100% by weight based on the total weight of all material components of the binder matrix, based on the specific composition of the binder matrix. Typical nickel-based superalloys contain primarily nickel and other metal components in the strengthened state of the γ-γ 'phase (γ-γ' phase-strengthened state), so as the temperature increases Strength increases.

  Various nickel-based superalloys such as Rene-95, Udimet-700, Udimet are available from Special Metals, which contains Ni and contains Co, Cr, Al, Ti, Nb, W, B and Zr. The -720 alloy has a lower melting point than Co, a common binder material. Therefore, when only such a nickel base superalloy is used as a binder material, the melting point of the resulting cemented carbide does not become higher than that of a cemented carbide using a Co-containing binder.

However, in one embodiment, the nickel-based superalloy is used in a binder to provide high material strength to the resulting cemented carbide and to a high or near 500 ° C of the resulting cemented carbide. Material hardness at temperature can be improved. Several manufactured samples were tested and found that the material hardness and material strength of cemented carbide containing nickel-based superalloy in the binder were similar materials that did not contain nickel-based superalloy in the binder. Compared to the composition, it showed a significant improvement, for example at least 10%, at low operating temperatures. The measured values of the hardness parameters of the samples P65 and P46A containing the nickel-base superalloy in the binder are shown in the following table in comparison with the samples P49 and P47A containing pure Co as the binder. The compositions of these samples are listed in Table 4.

  In particular, at high operating temperatures above 500 ° C., a cemented carbide sample containing a nickel-based superalloy in the binder is significantly more than a similar cemented carbide sample that does not contain a nickel-based superalloy in the binder. High material hardness can be exhibited. Furthermore, nickel-based superalloys as binder materials can improve the resistance of the resulting cemented carbide or cermet to corrosion compared to cemented carbide or cermet using conventional cobalt as a binder. .

  Nickel-based superalloys can be used alone or in combination with other elements to produce the desired binder matrix. Other elements that can be combined with a nickel-based superalloy to produce a binder matrix include, but are not limited to, other nickel-based superalloys, other non-nickel-based alloys, Re, Co, Ni, Fe, Mo, and Cr. .

Rhenium can be used as a binder to strongly bond hard particles, and in particular can provide a high melting point to the resulting cemented carbide material. The melting point of rhenium is about 3180 ° C., which is much higher than the melting point of 1495 ° C. of cobalt normally used as a binder material. This characteristic of rhenium contributes in part to the improved performance of cemented carbides containing binders using Re, such as the improved hardness and strength of the resulting cemented carbides at high temperatures. . Re also has other desirable properties as a binder material. For example, the hardness, transverse fracture strength, fracture toughness and melting point of a cemented carbide containing Re in its binder matrix are significant compared to similar cemented carbides not containing Re in the binder matrix. Can be high. A hardness Hv in excess of 2600 kg / mm ² has been achieved with a typical WC-based cemented carbide containing Re in the binder matrix. Some representative WC-based cemented carbides have shown melting points or sintering temperatures above 2200 ° C. In comparison, as shown in Table 2.1 of the Brookes document cited above, the sintering temperature of the WC-based cemented carbide containing Co in the binder is lower than 1500 ° C. A cemented carbide with a high sintering temperature can operate the material at high temperatures below the sintering temperature. For example, such a tool based on a cemented carbide material containing Re can be operated at high speed to shorten the machining time and increase the total throughput of machining.

  However, the use of Re as a cemented carbide binder material has practical limitations. For example, the preferred high temperature properties of Re generally increase the sintering temperature during manufacture. Thus, a normal sintering process oven or furnace needs to be operated at or above a high sintering temperature. Ovens or furnaces that can operate at such high temperatures, for example above 2200 ° C., are expensive and therefore not widely available for commercial use. U.S. Pat. No. 5,476,531 uses a rapid omnidirectional compaction (ROC) method, using pure Re as a binder material, and from 6% to the total weight of each cemented carbide. It is disclosed to reduce the processing temperature when producing a WC-based cemented carbide containing 18%. However, since this ROC method is still expensive, it is generally unsuitable for commercial production.

  One promising advantage of the cemented carbide composition and method of manufacture described herein is to produce a cemented carbide containing Re or a mixture of Re and other binder materials in a binder matrix. To provide or enable a more practical manufacturing method. In particular, the two-step process of the present invention makes it possible to produce cemented carbides that are 25% or more than 25% of the total weight of the cemented carbide matrix of Re produced. High hardness and material strength can be achieved at high temperatures using such cemented carbides containing 25% or greater than 25% Re.

  In addition, the use of pure Re as a cemented carbide binder material is limited because Re is severely oxidized in air at or above about 350 ° C. Due to this poor oxidation resistance, pure Re is rarely used as a binder in any application above about 300 ° C. Nickel-based superalloys have exceptional strength and oxidation resistance at temperatures below 1000 ° C, so using a mixture of nickel-based superalloys and Re (Re is the dominant material in the binder) The strength and oxidation resistance of the cemented carbide produced by using such a mixture as a binder can be improved. On the other hand, when Re is added to a binder mainly containing a nickel-base superalloy, the melting range of the resulting cemented carbide is increased, and the strength and creep resistance of the nickel-base superalloy binder at high temperatures are improved. The

  In general, the weight percentage of rhenium in the binder matrix is from a few percent to almost 100% of the total weight of the binder matrix in the cemented carbide. The weight percentage of rhenium in the binder matrix is preferably 5% or greater than 5%. In particular, the weight percentage of rhenium in the binder matrix may be 10% or more than 10% of the binder matrix. In some embodiments, the weight percentage of rhenium in the binder matrix may be 25% or greater than 25% of the total weight of the resulting cemented carbide binder matrix. Such a cemented carbide containing a high concentration of Re can be produced at a relatively low temperature by the two-step method described herein.

  Since rhenium is generally more expensive than other materials used in cemented carbide, cost must be considered when designing a binder matrix containing rhenium. Some of the examples shown below reflect this consideration. In general, according to one embodiment, the cemented carbide composition comprises hard particles containing and dispersed a first material, and a binder matrix containing a second different material comprising rhenium, wherein The hard particles are spread substantially uniformly dispersed in the binder matrix. Other binders that reduce the total content of Re to include Re and other binder materials that partly reduce the overall cost of the raw materials and in part increase the performance of the binder matrix It is a mixture with the material. Examples of binder matrices containing a mixture of Re and other binding materials include a mixture of Re and at least one nickel-based superalloy, a mixture of Re and Co and at least one nickel-based superalloy, and a combination of Re and Co. There is a mixture.

Table 1 lists some examples of the subject cemented carbide compositions. The WC-based composition in this table is referred to as “Cemented Carbide” and the TiC-based composition is referred to as “Cermet”. Traditionally, TiC particles bonded by a mixture of Ni and Mo or a mixture of Ni and Mo ₂ C are cermets. The cermets described herein further include TiC and TiN or TiC, TiN, WC, TaC and NbC containing a binder matrix produced by a mixture of Ni and Mo or a mixture of Ni and Mo ₂ C. There are hard particles made of the mixture. For each cemented carbide composition, three different weight percent ranges in these compositions of a given binder material are listed. An example is a composition in which the binder is a mixture of nickel-based superalloy and cobalt and the hard particles are a mixture of WC, TiC, TaC and NbC. In this composition, the binder may be about 2% to about 40% of the total weight of the cemented carbide. This range may be set to about 3 to about 35% for some applications, and may be further limited to a smaller range of about 4 to about 30% for other applications.

  A cemented carbide containing Re or a nickel-based superalloy in the binder matrix can be produced as follows. First, a powder containing the desired hard particles, for example, desired hard particles such as one or more carbides or carbonitrides, is prepared. The powder may contain a mixture of different carbides or a mixture of carbides and nitrides. This powder is mixed into a suitable binder matrix material containing Re or a nickel-based superalloy. A pressing lubricant, such as a wax, may be further added to the mixture.

  The mixture of hard particles, binder matrix material and lubricant is mixed in a grinding or attrition process by milling or attriting for a desired period of time, for example, multiple hours, to fully mix the materials. Each hard particle is coated with a binder matrix material to facilitate the bonding of the hard particles in the next step. Also, the hard particles must be coated with a lubricating material to lubricate these materials to facilitate the mixing process and reduce or eliminate oxidation of the hard particles. Next, compression, pre-sintering, forming and final sintering are subsequently performed on the above pulverized mixture to produce a cemented carbide. The sintering step is a step of converting the powder material to a continuous mass by heating to a temperature lower than the melting temperature of the hard particles, and can be performed after pre-compression by pressure. During this process, the binder material is densified to form a continuous binder matrix in which the hard particles are bound. Furthermore, one or more additional coatings can be formed on the surface of the resulting cemented carbide to improve the performance of the cemented carbide. FIG. 1 is a flowchart of this embodiment of the manufacturing process.

  In one embodiment, the cemented carbide manufacturing process includes wet milling in a solvent, vacuum drying, compression, and liquid phase sintering under vacuum. The temperature of the liquid phase sintering is between the melting point of the binder material (eg, 1495 ° C. for Co) and the eutectic temperature of the cemented carbide mixture (1320 ° C. for WC · Co). In general, the sintering temperature of cemented carbide ranges from 1360 ° C to 1480 ° C. For new materials with a low concentration of Re or nickel-based superalloy in the binder alloy, the manufacturing process is the same as the conventional cemented carbide process. In this case, the principle of liquid phase sintering under reduced pressure is applied. The sintering temperature is slightly higher than the eutectic temperature of the binder alloy and carbide. For example, the sintering condition of P17 (Re in the binder alloy is 25% by weight) is 1 hour at 1700 ° C. under reduced pressure.

  FIG. 2 shows a two-step manufacturing method based on solid-state phase sintering for manufacturing various cemented carbides described in the present application. An example of a cemented carbide that can be produced by this two-step sintering method is a cemented carbide containing a high concentration of Re in the binder matrix. Lower liquid phase sintering may be necessary. This two-step process can be carried out at a relatively low temperature, for example, below 2200 ° C., to produce a cemented carbide using a commercially viable oven and at a reasonably low cost. Liquid phase sintering is excluded from this two-step method because it is impractical because the eutectic temperature of the binder alloy and carbide is generally high. As discussed above, such high temperature sintering requires ovens that operate at high temperatures that are not commercially feasible.

  The first step of this two-step process is vacuum sintering in which a mixture of binder material and hard particles is sintered under reduced pressure. The mixture is first processed by conventional methods of producing cemented carbides, such as wet grinding, drying and pressing. This first step of sintering is performed at a temperature below the eutectic temperature of the binder alloy material and the hard particulate material to remove the interconnecting pores. The second step is solid-phase sintering performed in a compressed state at a temperature lower than the eutectic temperature. After performing the first step, pores and voids remaining in the sintered mixture are removed. Excluded. As this second step sintering method, a hot isostatic pressing (HIP) method can be used. During sintering, both the heat and pressure are applied to the material, and the processing temperature, which is elevated because other methods do not apply pressure, is lowered. A gaseous medium such as an inert gas is used to apply pressure to the mixture to be sintered. The pressure is 1000 bar or more than 1000 bar. When pressure is applied by the HIP method, the required processing temperature is lowered and a conventional oven or furnace can be used. The temperature of the solid phase sintering method and the HIP method for obtaining a sufficiently densified material is generally significantly lower than the temperature of the liquid phase sintering method. For example, sample P62 using pure Re as a binder is about 1 to 2 hours at 2200 ° C. under reduced pressure sintering for 1 to 2 hours, followed by about 1 000 PSI in an inert gas such as Ar at about 2000 ° C. It can be sufficiently densified by the time HIP method. In particular, if ultrafine hard particles having a particle size of less than 0.5 microns are used, the sintering temperature is lowered, and the cemented carbide (fine particles are several microns in size) can be completely densified. For example, when samples P62 and P63 are manufactured, the use of such ultrafine WC results in a low sintering temperature, for example, about 2000 ° C. Since this two-step method is less expensive than the ROC method, it can be used for commercial production.

  Representative cemented carbide compositions based on various binder matrix materials containing at least rhenium or nickel based superalloys and their properties are described below.

  Table 2 provides a list of code names (lot numbers) of some component materials used to produce a typical cemented carbide. That is, H1 represents rhenium, and L1, L2, and L3 represent three typical industrial nickel-based superalloys. Table 3 also lists the compositions of each of the three representative nickel-based superalloys: Udimet 720 (U720), Ren'95 (R-95), and Udimet 700 (U700). Table 4 lists the compositions of typical cemented carbides containing and not containing rhenium or nickel based superalloys in the binder matrix. For example, the material composition of lot P17 mainly comprises 88 g of T32 (WC), 3 g of I32 (TiC), 3 g of A31 (TaC), 1.5 g of H1 (Re) and 4.5 g of L2 (R-95). And 2 g of wax as a lubricant. Lot P58 is a cemented carbide containing nickel-based superalloy L2 as the only binder material that does not contain Re. These cemented carbides were manufactured and tested to show the effect on the various properties of the cemented carbide produced by either or both of the rhenium and nickel base superalloys as binder materials. Tables 5-8 further provide information summarizing the composition and characteristics of the different sample lots.

3-8 show the measured values of selected cemented carbide samples of the present application. Figures 3 and 4 show the measured toughness and hardness parameters of some representative cemented carbides of steel cutting grade. FIGS. 5 and 6 show the measured toughness and hardness parameters of some representative cemented carbides for non-ferrous cutting grades. Measurements were performed before and after the solid phase sintering HIP process, but the data suggests that the HIP process significantly improves both the toughness and hardness of the material. FIG. 7 shows hardness measurements as a function of temperature for several samples. For comparison, FIGS. 7 and 8 also show measurements of commercial carbides C2 and C6 under the same test conditions, FIG. 7 shows hardness measurements, and FIG. 8 shows hardness values at room temperature (RT). Shows the measurement results of changes. Cemented carbide samples based on the composition described in this application are clearly superior to commercial grade materials in terms of hardness at high temperatures. These results show that a binder matrix containing either or both Re and a nickel-based superalloy as a binding material outperforms a Co-based binder matrix material.

  Several representative categories of cemented carbide compositions are described below to illustrate the above general design of various cemented carbide compositions containing either or both Re and nickel-based superalloys. A typical category of cemented carbide compositions is defined based on the composition of the binder matrix used in the resulting cemented carbide or cermet. The first category uses a binder matrix containing pure Re, the second category uses a binder matrix containing a Re-Co alloy, and the third category uses a binder matrix containing a nickel-based superalloy. A fourth category uses a binder matrix containing a nickel-based superalloy combining Re and Co or a nickel-based superalloy combined with Re without Co.

The hard and refractory particles used in the subject cemented carbide are generally, but not limited to, carbides, nitrides, carbonitrides, borides, and silicides. Some examples of carbide, WC, some _{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 (C, N), Hf (C, N), Zr (C, N) and V (C, N). . Examples of borides is _{TiB 2, ZrB 2, HfB 2} , TaB 2, VB 2, MoB 2, WB and _{W 2} B. Examples of further silicide is TaSi _{2, WSi 2,} NbSi ₂ and MoSi _2. The above four categories of cemented carbide or cermet can also use these and other hard and refractory particles.

In the first category of cemented carbides based on a binder matrix of pure Re alloy, Re may be approximately 5-40% by volume of the total material composition used in the cemented carbide or cermet. For example, the sample of lot number P62 in Table 4 has a pure Re of 10% by volume, WC of 70% by volume, TiC of 15% by volume, and TaC of 5% by volume. This composition corresponds to 14.48 wt% Re, 75.43 wt% WC, 5.09 wt% TiC and 5.0 wt% TaC. Sample P62-4 was sintered at 2100 ° C. for about 1 hour and then at 2158 ° C. for about 1 hour at the time of manufacture. The density of this material is about 14.51 g / cc, and the calculated density is 14.50 g / cc. The average hardness Hv obtained by measuring 10 times under a load of 10 kg at room temperature is 2627 ± 35 kg / mm ² . The measured surface fracture toughness KSC is approximately 7.4 × 10 ⁶ Pa · m ^1/2 estimated by the Palmvist crack length at 10 kg load.

Another example of this category is P66 shown in Table 4. The composition of this sample is about 20 volume% Re, 60 volume% WC, 15 volume% TiC and 5 volume% TaC. This sample, when expressed by weight%, has Re of about 27.92%, WC of 62.35%, TiC of 4.91% and TaC of 4.82%. Sample P66-4 is first treated by a reduced pressure sintering method at about 2200 ° C. for 1 hour, and then sintered by a HIP method in a solid phase to remove pores and voids. The density of the resulting cemented carbide is about 14.40 g / cc compared to a calculated density of 15.04 g / cc. The average hardness Hv obtained by measuring 7 times under a load of 10 kg at room temperature is about 2402 ± 44 kg / mm ² . Its surface fracture toughness KSC is about 8.1 × 10 ⁶ Pa · m ^1/2 . Sample P66 and other compositions described herein containing Re as a single binder material or one of two or more binder materials in a binder at a high concentration of greater than 25 wt. It can be used for various applications with high operating temperatures, and can be produced by utilizing a two-step method based on solid phase sintering.

The microstructure and properties of multiple types of hard refractory particles bonded with Re, for example, carbides, nitrides, carbonitrides, silicides and borides, can provide advantages over Re bonded WC materials. . For example, Re bonded WC-TiC-TaC has a better crater resistance than Re bonded WC material when cutting steel. Another example is a material made of Mo ₂ C and TiC refractory particles bonded in a Re binder.

  In the second category containing Re-Co alloy as the binder matrix, the Re-Co alloy is about 5-40% by volume of the total material composition used in the composition. In some embodiments, the ratio of Re to Co in the binder can vary within the range of about 0.01 to 0.99. Inclusion of Re can improve the mechanical properties of the resulting cemented carbide, such as the unique hardness, strength and toughness at high temperatures compared to Co bonded cemented carbide. For most materials that use such a binder matrix, the higher the Re content, the better the properties at high temperatures.

Sample P31 shown in Table 4 is an example that falls within this category, with volume% Re 2.5%, Co 7.5% and WC 90%, and weight% Re 3.44%. , Co is 4.40% and WC is 92.12%. Sample P31-1 was sintered under reduced pressure at 1725 ° C. for about 1 hour at the time of manufacture, but there were slight pores and voids during sintering. The resulting cemented carbide has a density of about 15.16 g / cc (calculated density is 15.27 g / cc). The average hardness Hv is about 1889 ± 18 kg / mm ² at a load of 10 kg at room temperature, and the surface fracture toughness Ksc is about 7.7 × 10 6 Pa · m ^1/2 . Further, Sample P31-1 was sintered and then processed by hot isostatic pressing (HIP) at about 1600 ° C./15 Ksi for about 1 hour. This HIP method reduces or substantially eliminates pores and voids in the compound and increases the density of the material. After performing the HIP method, the measured density is about 15.25 g / cc (calculated density is 15.27 g / cc). The measured value of hardness Hv at a load of 10 kg at room temperature is about 1887 ± 12 kg / mm ² . The surface fracture toughness Ksc is about 7.6 × 10 ⁶ Pa · m ^1/2 .

Another example in this category is P32 shown in Table 4, which is% by volume, 5.0% Re, 5.0% Co, and 90% WC (in weight%, Re is 6.75%). , Co is 2.88% and WC is 90.38%). Sample P32-4 was sintered under reduced pressure at 1800 ° C. for about 1 hour. The density measurement is about 15.58 g / cc compared to a calculated density of 15.57 g / cc. The measured value of hardness Hv is about 2065 kg / mm ² at a load of 10 kg at room temperature. The surface fracture toughness Ksc is about 5.9 × 10 ⁶ Pa · m ^1/2 . Sample P32-4 was also sintered and processed by the HIP method at 1600 ° C./15 Ksi for about 1 hour. The measured density is about 15.57 g / cc (calculated density is 15.57 g / cc). The average value of the hardness Hv is about 2010 ± 12 kg / mm ² at a load of 10 kg at room temperature. The surface fracture toughness Ksc is about 5.8 × 10 ⁶ Pa · m ^1/2 .

A third example is P33 as shown in Table 4, which is% by volume, 7.5% Re, 2.5% Co, 90% WC and 9.9% Re by weight. , Co is 1.41% and WC is 88.66%. Sample P33-7 was sintered under reduced pressure at 1950 ° C. for about 1 hour at the time of manufacture, but had pores and voids under sintering. The measured density is about 15.38 g / cc (calculated density is 15.87 g / cc). The measured value of hardness Hv is about 2081 kg / mm ² under a force of 10 kg at room temperature. Surface fracture toughness Ksc is about ^{5.6 × 10 6 Pa · m 1/2} . Sample P33-7 was sintered and processed by the HIP method at 1600 ° C./15 Ksi for about 1 hour. The measured density is about 15.82 g / cc (calculated density = 15.87 g / cc). The average value of the hardness Hv is about 2039 ± 18 kg / mm ² when measured under a force of 10 kg at room temperature. The surface fracture toughness Ksc is about 6.5 × 10 ⁶ Pa · m ^1/2 .

Samples P55, P56, P56A, and P57 shown in Table 4 are also examples of categories in which a Re—Co alloy is used as a binder matrix. These samples contain about 1.8% Re, 7.2% Co and 0.6% VC, except that P57 does not contain VC, and finally the rest is WC. These different compositions were made to investigate the effect of cemented carbide particle size on Hv and Ksc. Table 5 shows the test results.

  The third category is based on a binder matrix containing 5-40% by volume of nickel-base superalloy in the total cemented carbide material produced. Nickel-based superalloys are a family of high temperature alloys that are gamma prime strengthened. Three strong alloys: Rene'95, Udimet 720, and Udimet 700 are used as examples to illustrate the effect of binder strength on the mechanical properties of the resulting cemented carbide. Nickel-based superalloys are particularly strong at high temperatures. Further, these alloys are excellent in environmental resistance such as resistance to corrosion and oxidation at high temperatures. Therefore, using a nickel-base superalloy, the hardness of the cemented carbide bonded with this superalloy can be made higher than the hardness of the cemented carbide bonded with cobalt. In particular, the tensile strength of nickel-based superalloys is much higher than the usual binder material cobalt as shown in Table 6. This further indicates that nickel-based superalloys are excellent binder materials for cemented carbides.

An example of this category is P58 shown in Table 4, which contains 7.5% Ren'95, 0.6% VC, and 91.9% WC by weight, and is bound by the cobalt shown in Table 4. P54 (Co 8%, VC 0.6% and WC 91.4%). The hardness of P58 is significantly higher than P54 as shown in Table 7.

The fourth category is a cemented carbide using nickel base superalloy + Re as a binder, for example, about 5 to 40% by volume of the total material of the resulting cemented carbide or cermet. The binder alloy obtained by adding Re to a nickel-base superalloy has a higher melting point than the nickel-base superalloy, so as the Re content increases, the treatment of cemented carbide containing nickel-base superalloy + Re binder The temperature increases. A number of cemented carbides with different concentrations of Re are listed in Table 8. Table 9 further shows measured values of the properties of the cemented carbide shown in Table 8.

Another example to which the fourth category belongs is a cemented carbide which also uses about 5-40% by volume of nickel-based superalloy + Re and Co as binders. Typical compositions of nickel-base superalloys + cemented carbides combined with Re and Co are listed in Table 10.

  Measurements of selected samples were made to investigate the properties of binder matrices containing nickel-based superalloys. In general, nickel-base superalloys not only exhibit excellent strength at high temperatures, but also have significant oxidation and corrosion resistance at high temperatures. Nickel-based superalloys have complex microstructures and strengthening mechanisms. In general, the strengthening action of the nickel-base superalloy is mainly due to the precipitation strengthening action of the γ-γ 'phase and the strengthening action of the solid solution. Selected sample measurements indicate that nickel-based superalloys can be used as high performance binder materials for cemented carbides.

Table 11 lists the composition of the selected samples by weight percent of the total weight of the cemented carbide. The WC particles in these samples are 0.2 μm in size. Table 12 lists the conditions of the two-step method performed and the measured values of the sample density, hardness parameters and toughness parameters. The Palmgvist fracture toughness Ksc is calculated from the total crack length of the Palmgvist crack generated by the Vicker indenter [Ksc = 0.087 × (Hv × w) ^1/2 ] (Ksc = 0.087 * (Hv * W) ^1/2 ) (see, for example, Warren and H. Matzke, Proceedings Of the International Conference On the Science of Hard Materials, Jackson, Wyoming, USA, August 23-28, 1981). The hardness Hv and crack length were measured under a load of 10 kg for 15 seconds. Each measurement was performed by indenting 8 times for each sample, and the average value was used to calculate the listed data.

In the test sample, a conventional binder made of Co is used for the sample P54. In the sample P58, Ni superalloy R-95 is used instead of Co used as the binder in the sample P54. As a result, P58 is increased to 2246 while Pv is 2090 for Hv. In the case of sample P56, a mixture of Re and Co is used instead of Co as a binder, but Pv is increased to 2133 even though P54 is 2090 for Hv. Samples P72, P73, and P74 contain the same amount of Re but different amounts of Co and R95. The sample P72 uses a mixture of Re and Co as a binder, while the samples P73 and P74 use a mixture of Re, Co, and R95 as a binder instead. The hardness Hv increases from 2041 (P72) to 2217 (P73) and 2223 (P74).

The selected samples were also measured to further investigate the properties of the binder matrix containing Re in the binder matrix. Table 13 lists the test samples. Two types of WC particles having a particle size of 2 μm and 0.2 μm were used. Table 14 lists the conditions of the two-step method performed and the measured values of the selected sample density, hardness and toughness parameters.

Table 15 further shows the measured values of hardness parameters of the selected samples under various temperatures, where Knoop hardness Hk was measured with a NikonQM high temperature hardness tester for 15 seconds at a load of 1 kg. R is the ratio of Hk in the high temperature test to Hk at 25 ° C. Carbides of high temperature hardness samples C2 and C6 are available from MSC Co. (Insert SNU434, purchased from Melville, NY).

  When Re is contained in the binder matrix of the cemented carbide, the melting points of the binder alloys, that is, Co-Re, Ni superalloy-Re, and Ni superalloy-Re-Co are increased. For example, the melting point of sample P63 is much higher than the temperature of 2200 ° C. used in the solid phase sintering method. Such cemented carbides containing Re in the binder (eg, P17-P63) have much higher high-temperature hardness values than conventional Co-bonded cemented carbides (C2 carbide and C6 carbide). In particular, the above measured values indicate that the hardness at high temperature increases as the Re concentration in the binder increases. Among the test samples, sample P62A containing pure Re as a binder has the highest hardness. Sample P63 containing a binder composition with 94% Re and 6% nickel-base superalloy R95 has the second highest hardness. Samples P40A (71.9% Re-29.1% R95), P49 (69.9% Re-30.1% R95), P51 (88.5% Re-11.5% R95) and P50 (71. 9% Re-28.1% R95) is a group of values whose hardness follows the sample. Sample P48 containing 62.5% Re and 37.5% R95 in the binder has the lowest Re content, and therefore has the lowest hardness at high temperature among some of the test samples.

Yet another category of cemented carbide or cermet contains TiC and TiN bonded to a binder matrix containing Ni and Mo or Mo ₂ C. The cermet binder Ni can be completely or partially replaced by Re, Re + Co, nickel-base superalloy, Re + nickel-base superalloy, and Re + Co and nickel-base superalloy. For example, samples P38 and P39 are examples of cermets bonded with Ni. Sample P34 is an example of a cermet bonded with Rene95. P35, P36, P37 and P45 are cermets bonded by Re + Rene95. The compositions of P34, 35, 36, 37, 38, 39 and 45 are listed in Table 16.

Tables 17-29 list additional compositions having three exemplary composition ranges 1, 2, and 3 that can be used for different applications.

Tables 30-41 below list exemplary cermet compositions having three exemplary composition ranges 1, 2, and 3 that can be used for different applications.

  Tables 42-51 below list additional examples of various compositions having three exemplary composition ranges 1, 2, and 3 that can be used for different applications. Like some of the compositions described above, some of the compositions in Tables 42-51 appear to be particularly beneficial for high temperature applications as shown in the last row under "Estimated Melting Point". It is.

  As noted above, binder matrix materials using rhenium, nickel-based superalloys, 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 silicides. When used alone or in combination with other metals, tungsten can significantly increase the melting point of the final cemented carbide material to a range of about 2500 to about 3500 ° C. Thus, cemented carbides using W-based binder matrix materials can be used in high temperature applications not possible with other materials. In particular, some compositions using a binder matrix based on tungsten (W) shown in Tables 43-48 exhibit high melting points centered around 3500 ° C.

In the compositions made with rhenium and cobalt bonded nitrides in Table 47, each nitride is replaced by a combination of nitride and carbide as the hard particulate material. The material according to this design combines hard particles and hard particles comprising at least one nitride from Group IVB and VB nitrides of the periodic table and one carbide from Group IVB, VB and VIB carbides of the periodic table. And a binder matrix comprising rhenium and cobalt.

  The above composition of cemented carbide or cermet can be used for various applications. For example, such a material can be used to manufacture the wear part of a tool that cuts, grinds or drills the target object by cutting the material of the target object using the wear part. Such a tool may comprise support parts made of different materials, for example steel. In that case, the wear part is engaged with a support part as an insert. The tool can be designed with a plurality of inserts engaged with the support component. For example, some mining drills can be provided with a plurality of button bits made of cemented carbide material. Examples of such tools include cutting tools such as drills and knives, saws, grinders, and drills. Alternatively, the cemented carbide described herein can be used to produce the entire head of the tool as a wear part for cutting, drilling or other machining operations. In addition, cemented carbide particles can be used to produce abrasive grids used to polish or grind various materials. Furthermore, such cemented carbides can be used to produce housings and outer surfaces or outer layers for various devices that meet the specific requirements of the operation of the device or the environmental conditions under which the device operates.

  More specifically, the cemented carbide described herein can be used to produce cutting tools for machining metals, composites, plastics and wood. The cutting tools include throwaway inserts for turning, turning, boring and drilling, drills, end mills, sommers, taps, hobbs, and milling cutters. Since the temperature of the cutting edge of these tools can be higher than 500 ° C. during machining, the cemented carbide composition used for the above high temperature operating conditions is particularly advantageous when used for these cutting tools, for example, Productivity with these tools is improved by extending the life and increasing the cutting speed.

  The cemented carbide described herein can be used to produce tools for use in wire-drawing, extrusion, forging, and cold heading (cold heading). It can also be used as a mold or punch for the powder method. Furthermore, these cemented carbides can be used as wear resistant materials used for drilling or mining rocks.

  The cemented carbide materials described herein can be processed in bulk form or as a coating on a metal surface. Coating with such a new cemented carbide material can conveniently form a hard layer on the metal surface to achieve the desired hardness that would otherwise be difficult to achieve with the underlying metal material. Bulk cemented carbide materials based on the compositions of the present application are expensive and therefore can reduce the cost of various hard components or parts when used in low-cost, inexpensive metal coatings.

  Various powder preparation methods that produce commercially available cemented carbide can be used to produce the cemented carbide of the present application. For example, a binder alloy containing Re exceeding 85% by weight is made by a solid-phase sintering process to eliminate pores, and then replaced with liquid phase sintering by HIP.

  FIG. 9 shows a flowchart of a plurality of processing (manufacturing) methods for materials or structures from the above-mentioned cemented carbide composition. As illustrated, the alloy powder and hard particle powder for the binder can be mixed with the milling liquid by a wet mixing method with or without a lubricant (eg, wax). The processing flow on the left side of FIG. 9 is a flow for processing a cemented carbide by lubricated wet mixing. This mixture is first dried by vacuum drying or spray drying to produce a lubricating grade powder. Next, the lubricating grade powder is formed into a bulk material by pill pressing, extrusion molding, or cold isostatic pressing (CIP). CIP is a process of solidifying powder by isotropic pressure. The bulk material is then heated to remove the lubricant and sintered by a presintering method. The material can then be processed through a number of different processes. For example, the material can be processed via liquid phase sintering in vacuum or hydrogen and then further processed by the HIP method to form the final cemented carbide part. Alternatively, the pre-sintered material can be subjected to solid phase sintering to eliminate holes and then the final cemented carbide part can be formed by the HIP method.

  When the binder alloy powder and hard particle powder are mixed without a lubricant, the unlubricated grade powder after the drying process is processed in two different ways to form the final cemented carbide part. be able to. In the first method illustrated, processing is simply performed using a hot pressing method. In the second method, a thermal spray method is used to form a grade powder on a metal substrate in a vacuum. Next, the metal substrate is removed, and a structure by a thermal spraying method, which is a self-supporting material as a final cemented carbide part, is left. Furthermore, the self-supporting material can be processed by the HIP method, and openings can be reduced as necessary.

  When forming a cemented carbide coating on a metal surface, a thermal spray process can be used in a vacuum to produce large parts coated with a cemented carbide material. For example, the surfaces of steel parts and tools can be coated to improve hardness and thus performance. FIG. 10 shows an exemplary flowchart of the thermal spraying method.

Various thermal spraying methods for coating metal surfaces are known. For example, ASM Handbook Vol. 7 (P408, 1998) describes the thermal spraying method as a group of fine particle / droplet consolidation methods that can be formed into a coating or free-standing structure of metal, ceramics, intermetallic compounds, composite materials, and polymers. Yes. In that method, powders, wires, or rods can be placed in a combustion or arc heated jet where they are heated, melted or softened, accelerated, and coated toward the surface or substrate. Upon impact on the substrate, the particles or droplets rapidly solidify, cool, shrink, and gradually accumulate, forming a deposit on the target surface. A thin “flat plate” can have a high cooling rate, for example, a cooling rate of more than 10 ⁶ K / s in the case of metals.

  Thermal spraying uses chemical (combustion) or electrical (plasma or arc) energy to heat the raw material charged into the hot gas jet, forming a stream of molten droplets, accelerating, Coat towards the material. 3 and 4 show ASM Handbook Vol. 7 shows various spraying methods on pages 409-410.

  Various details of the spraying method are described in Lawley et al. “Spray Forming” and Knight et al. “Thermal Spray Forming of Materials”, respectively, ASM Handbook Volume 7 ol p ) Pages 396 to 407 and 408 to 419.

  The selected cemented carbide compositions described herein can maintain high material strength and hardness at high temperatures, 1500 ° C., or above 1500 ° C. Certain high power engines, such as various jet engines and / or rocket engines used in various flying devices and airplanes, operate at such high temperatures. More specifically, the jet nozzle and / or rocket nozzle, including the throat and low corrosive nozzles of these and other engine non-corrosive nozzles, are selected cemented carbide materials as described in this application, It can be formed partly or wholly.

For example, (1) one or more carbides, (2) one or more nitrides, (3) one or more borides, and (4) (1), (2) and (3) A cemented carbide based on one or more of a combination of two or more and a binder material that is pure Re or a composite binder material having Re as a component. The melting points of various carbides, nitrides, and borides in this application are above 2400 ° C. Examples of suitable carbides for the high temperature cemented carbide material of the present invention include TaC, HfC, NbC, ZrC, TiC, WC, VC, Al ₄ C ₃ , ThC ₂ , Mo ₂ C, SiC and B ₄ C. Is mentioned. Examples of suitable nitrides for the high temperature cemented carbide material of the present invention include HfN, TaN, BN, ZrN, and TiN. Examples of suitable borides for the high temperature cemented carbide material of the present invention include HfB ₂ , ZrB ₂ , TaB ₂ , TiB ₂ , NbB ₂ , and WB. Two examples of composite binder materials in which Re is a component are (1) W and Re, and (2) Ta and Re.

  This specification contains many details, which should not be construed as limiting the scope of the invention or claims, but as describing features that are specific to particular embodiments of the invention. It is. Certain features that are described in this specification in separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in a single embodiment can be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, even if a feature is described above as acting in a particular combination and initially claimed as such, one or more features of the claimed combination may, in some cases, be from that combination. The combinations that can be deleted and claimed can be directed to partial combinations or variations of partial combinations.

  Only a few implementations and examples are disclosed. However, it will be understood that several variations and modifications can be made.

1 illustrates one exemplary manufacturing flow for a cemented carbide according to an embodiment of the present invention. A representative two-step sintering process for treating cemented carbide in the solid phase is shown. The measured values of various properties of selected representative cemented carbides are shown. The measured values of various properties of selected representative cemented carbides are shown. The measured values of various properties of selected representative cemented carbides are shown. The measured values of various properties of selected representative cemented carbides are shown. The measured values of various properties of selected representative cemented carbides are shown. The measured values of various properties of selected representative cemented carbides are shown. An example of thermal spraying is shown. An example of thermal spraying is shown.

Claims (23)

Hard particles containing at least one carbide formed by selecting 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;
A binder matrix that binds the hard particles and comprises rhenium;
Containing material.   The material of claim 1, wherein the hard particles are less than 75% of the total weight of the material and rhenium is greater than 25% of the total weight of the material.   The material of claim 1, wherein the hard particles further comprise at least one nitride selected from at least one of HfN, TaN, BN, ZrN, and TiN. The material of claim 1, wherein the hard particles further comprise at least one boride selected from at least one of HfB ₂ , ZrB ₂ , TaB ₂ , TiB ₂ , NbB ₂ , and WB.   The material of claim 1, 2, 3, or 4, wherein the binder matrix further comprises W.   5. A material according to claim 1, 2, 3, or 4 wherein the binder matrix further comprises Ta. Hard particles comprising at least one nitride selected from at least one of HfN, TaN, BN, ZrN, and TiN;
A binder matrix that binds the hard particles and comprises rhenium;
Including material.   The material of claim 7, wherein the hard particles are less than 75% of the total weight of the material and rhenium is greater than 25% of the total weight of the material. The hard particles further include 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. 8. The material of claim 7, comprising. The material according to the hard _particles, the _{HfB 2, ZrB 2, TaB 2} , TiB 2, NbB 2, and further comprising at least one boride selected from at least one of WB, claim 7.   11. A material according to claim 7, 8, 8, or 10, wherein the binder matrix further comprises W.   11. A material according to claim 7, 8, 8, or 10, wherein the binder matrix further comprises Ta. 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;
A binder matrix that binds the hard particles and comprises rhenium;
Including material.   14. The material of claim 13, wherein the hard particles are less than 75% of the total weight of the material and rhenium is greater than 25% of the total weight of the material.   The material of claim 13, wherein the hard particles further comprise at least one nitride selected from at least one of HfN, TaN, BN, ZrN, and TiN. The hard particles further include 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. 14. The material of claim 13, comprising.   The material of claim 13, 14, 15, or 16, wherein the binder matrix further comprises W.   17. A material according to claim 13, 14, 15, or 16, wherein the binder matrix further comprises Ta.   A jet nozzle comprising the material according to claim 1.   A non-corrosive nozzle throat comprising the material of any one of claims 1-18.   A nozzle throat comprising the material according to claim 1.   A method comprising forming at least a portion of a jet nozzle using the material of any one of claims 1-18.   19. A method comprising the step of forming at least a portion of a nozzle using the material of any one of claims 1-18.

Images