KR101215656B1 - Method for consolidating Tough Coated Hard Powders - Google Patents

Abstract

A liquid phase sintering method is provided for molding particulate matter into articles having a combination of physical properties not obtainable by conventional processes. This particulate material consists of the core particles individually coated with a layer of metal compound having a relatively higher fracture toughness than the core such as WC or TaC. Such coated particles include an outer layer comprising a metal such as Co or Ni. Particles with such a coating are pressed to form articles, which are densified at pressures and temperatures where sufficient density is obtained without decomposition of the material forming the core particles.

Sintering, Fracture Toughness, Toughness, Hard Powder, Coating, Densification, Core, Interlayer, Outer Layer

Description

Method for forming hard powder coated to have high performance {Method for consolidating Tough Coated Hard Powders}

Disclosed are methods for forming Tough-Coated Hard Powders (TCHP) coated with high performance to a sufficient density in nature without low pressure or pressurization, and articles molded by the method. The method is a cost effective method of making a sintered body of TCHP material by liquid sintering that provides increased value over conventional hard articles and tool materials known in the art. to be.

Sintering can be defined as a compaction for joining the particles together to make a heat treatment of the powder or a solid article.

In applications in which the powder consists of a mixture of powders of at least two different materials with different melting points, the powder mixture is compacted into a green body. This body is heated above the melting point of the composition having the lowest melting point, and the powder mixture, in which a certain part of the compaction is loosened, is liquefied. After treating the body at a sintering temperature for a predetermined time, the material cools, the liquid solidifies and the body solidifies into a compacted useful structure. Examples of such configurations are Cu / Sn, Fe / Cu and tungsten carbide / Co.

In this process, densification of the compacted object occurs under liquid phase, and this sintering process is called liquid phase sintering (LPS). In this configuration, LPS, which is especially a molding of hard metals such as tungsten carbide and other ceramic particles, is sometimes called conventional sintering. In the LPS process, it is advantageous to have a minimal liquid phase present at the sintering temperature that ensures movement of the binder phase in order to achieve uniform distribution and densification. It is also generally advantageous to limit the amount of liquid present to avoid partial shape deformation and grain growth.

Such liquefaction enables, for example, mass transfer, particle rearrangement, growth and densification of the framework structure. It is generally believed that this phenomenon is achieved by rounding the particles when external irregularities are liquefied, and by the movement of these liquids to fill the voids. When cooled, recrystallization and tissue growth often occur. Porosity as a percentage of the total volume may decrease due to the densification of the structure. The densification rate can be influenced, for example, by the sintering temperature, sintering time, sintering pressure, sintering atmospheric pressure and the weight fraction of added binder component.

Liquid phase sintering of conventional hard metals, such as tungsten carbide-cobalt (WC-Co) compacts, is generally performed at a sintering temperature range of 1325 to 1475 ° C.

When the WC-Co dense is heated during the sintering of the WC-Co hard metal, the cobalt begins to behave like a very viscous liquid at about 700 ° C, and as the temperature of the cobalt decreases correspondingly, the temperature increases. As a result, diffusion increases. The oil-like action and viscosity of Co metal is believed to produce capillary attraction that results from Co's strong tendency to wet the WC surface as much as possible. This causes rearrangement of the WC particles, and the composite begins to shrink before the first liquid phase is formed.

At 1275 ° C., the cobalt binder metal begins to dissolve the WC particles and the three-way eutectic reaction begins and forms a Co—W—C alloy. As the temperature continues to rise, as the tissue boundary moves through the interface between the WC tissue and the Co binder phase, the increased surface wetting, liquefaction, and capillary phenomena lead to continuous particle rearrangement and to the shape of the desired article of powder material. Causes contraction of.

High density, homogenization and WC stoichiometry in the sintered part are fundamental requirements for WC-Co microstructure integrity and strength. Maintaining an appropriate local carbon balance during liquid sintering is necessary to prevent formation of fragile carbon deficient CO ₃ W ₃ C eta phase and formation of carbon pores produced by too much carbon. It is also important in providing the fracture toughness of the Co material. The prevention of strength-robbing porosity and tissue growth in the microstructure can be achieved through the selection of an appropriate sintering temperature and sintering pressure. For example, while maintaining the temperature low enough to avoid excessive dissolution of the WC causing tissue growth, the temperature must be high enough to liquefy the appropriate amount of material to achieve sufficient mass transfer to fill the voids between the particles. Should be. Since capillary action is insufficient to provide densification to approach theoretical density, external pressure may be applied.

In conventional sintering processes, small amounts (3-18 wt%) of cobalt are usually mixed with WC. The cobalt binder serves to increase the density, and uniform distribution of the cobalt binder is required in order to obtain uniformity of the WC-Co microstructure. Microstructural defects are generally found in sintered WC-Co parts. A common cause is incomplete blending of WC and Co powders having essentially the same diameter (in spite of prolonged mixing). This process preferably encapsulates (or at least combines) each WC particle with an appropriate amount of Co so that the Co-to-WC ratio is essentially uniform through mixing. Statistically, it is impossible to achieve this result because there is no cobalt of nanoparticles small enough to mix uniformly with the WC particles. Cobalt oxidation, explosive spontaneous reactions and particle aggregation are obstacles to their availability.

The result is a WC-Co mixture with Co-rich and Co-poor areas. Firstly, the liquid phase occurs in areas where Co is excessive, and WC-unsaturated cobalt is (a) consumed by smaller adjacent WC crystals (the smallest can be consumed completely), and (b) until saturated. Thermodynamic equilibrium is sought by moving unsaturated Co through long distances to Co-lack regions to dissolve many WCs. Thus, a temperature higher than the temperature necessary to produce the liquid phase is required to move and liquefy the cobalt to the Co deficiency area—an equilibrium and sufficient Co liquid is required to wet the WC particles.

In order to eliminate this non-uniform Co distribution, (a) very long ball milling time, (b) higher sintering temperature, and (c) longer sintering time are typically done. Ball milling makes many WC particles into fine particles and is preferably dissolved by Co during heating. The latter two cases unfold the binder phase and normalize the distribution of liquid cobalt during sintering, but also increase the solubility of WC. Also, as long as at least the boundary of the tissue is present at an interface angle almost perpendicular to the surface, the amount of Co is due to the fact that the WC / WC interface energy is greater (in positive direction) than the interface energy of WC / Co. It will penetrate the WC particles along the boundary. Upon cooling, the saturated WC-Co solution precipitates WC and, when solidification occurs, preferentially forms a core and recrystallizes the WC on the remaining larger, undissolved WC crystals, resulting in undesired Ostwald life. ripening (tissue growth) occurs. This tissue growth continues until the temperature decreases below the 1275 ° C. ternary melting point of the Co-W-C structure. 1 shows a pseudobinary WC-Co phase diagram. Nearly 100% sintered density is natural for WC-Co materials.

Thus, increasing the sintering temperature increases binder fluidity but also results in excessive WC dissolution, resulting in undesired tissue growth. There is a balance between the sintering temperature and the sintering time that should be carefully balanced. Sufficient to achieve the necessary mass transfer to fill the space between the particles (damaging the structural strength) while trying to avoid too high temperature and too long time to avoid tissue growth (which also reduces structural strength). The temperature must be high enough to liquefy the material.

Since control of the sintering temperature is one major factor for high quality hard metal microstructures, alternative sintering techniques have been introduced. These techniques include studies that reduce sintering time (ie microwave sintering), gas pressure (ie hot pressing, hot isotatic prssing, and ceracon and lock-tec sinter-forging methods). Ceracon and Roc-Tec sinter-forging methods).

Another study used to form conventional hard metals is to increase the weight fraction of a binder such as cobalt. It may range from 18-25% by weight. This can have the beneficial effect of increasing the amount of liquid present as well as increasing the toughness of the structure. However, this approach has two major drawbacks and is therefore generally avoided. First, an increase in the weight percentage of the binder reduces the weight percentage of WC (abrasion resistant phase) in its structure and thus reduces wear resistance. Secondly, increasing the amount of Binder binders contributes significantly to tissue growth upon cooling and also dissolves more WC.

In addition, the only way to improve the wear resistance of conventional carbides (although they retain the high fracture toughness of WC-Co substrates) for the past 70 years has been (a) to continuously purify and improve conventional powder and molding process methods (b ) A thin, wear resistant coating was added, and (c) a harder material was laminated onto the WC-Co substrate. Improving conventional WC-Co microstructures is a precise balance of time, temperature, tissue size, and other products and process variables. Incremental improvements of conventional carbides have been achieved over the past 50 years through better firing temperature control and higher purity, higher uniform WC-Co starting powders. Since the introduction of the outer coating more than 30 years ago, the improvement in the wear resistance of materials with the toughness of WC-Co has almost stopped and delayed.

Although this technique has reduced the problems arising in the conventional liquid phase sintering of hard metals, particles having properties that allow uniform properties through sintering of WC and binder powders and articles formed from such particles. There has been an unsatisfactory need for a way to produce it.

In order to avoid the drawbacks described above, the present invention provides a new class of engineered microstructured particulate materials with an unprecedented combination of high properties called tough-coated hard powders (TCHPs, or EternAloy ^® ). It provides a method of molding by liquid phase sintering. This new class of sintered particulate materials includes one or more types of superhard Geldart Class C or larger ceramic or refractory alloy core particles having the best wear resistance, lubricity and other properties. The properties are (1) individually coated with a nanolayer of a metal compound having a relatively high fracture toughness such as WC or TaC, and (2) again with a second layer comprising a binder metal such as Co or Ni. In order to provide materials with superior properties not available from homogeneous powders sintered so far, combinations of alloys with various properties within the TCHP sintered structure are not limited to conventional, including toughness, abrasion, chemical wear resistance and light weight. Allows a combination of the highest performances. TCHP materials are described in US Pat. 6,372,346, which is incorporated herein by reference.

The process of the present invention allows the integration of thermodynamically incompatible material phases and good physical properties seen in a single material. Thus, the TCHP material can be designed to have both diamond hardness, greater fracture toughness than tungsten carbide, and nearly titanium. As a result, TCHPs are significantly improved in conventional metal cutting and forming tools; abrasive; Friction and wear products and thermal coatings; And cars, airplanes. Heavy industry and defense installations; It can surpass the wear resistance of

As noted above, a method of making an article from particulate material is provided. The method comprises metal and metalloid nitrides, metal and metalloid carbides, metal and metalloid carbides, metal and metalloid borides, metal and metalloid oxides, metal and metalloid sulfides, metal and metalloid sulfides, and diamond Providing a plurality of core particles composed of one core particle material selected or a plurality of other core particle materials selected.

The intermediate layer is provided on the plurality of core particles. The intermediate layer comprises a second compound that differs in composition from the core particle material and has a higher relative fracture toughness. The second compound may bind with the core particle material and with a metal selected from Fe, Co, Ni, Cu, Ti, Al, Mg, Li, Be, Ag, Au, Pt and their alloys. . The combination of the core particles and the intermediate layer forms coated particles.

An outer layer is introduced into the coated particles. The outer layer comprises a metal selected from the group consisting of Fe, Co, Ni, and combinations thereof, and forms a substantially continuous outer layer on the intermediate layer. The combination of the coated particles and the outer layer forms a composite particle.

A plurality of said compositional particles is shaped into an article.

The article is sintered to a sufficient density without significant external molding pressure for a time sufficient to dissolve the portion of the intermediate layer in liquid formed from the outer layer at a temperature sufficient to liquefy at least a portion of the outer layer.

The liquid formed from the outer layer and the intermediate layer solidifies before significant detrimental interaction of the liquid with the core particles.

In one embodiment, the core particle material has _a formula of M _a X _b , wherein M is Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Mg, Cu, and A metal selected from Si; X is an element selected from nitrogen, carbon, boron, sulfur, and oxygen; a and b are integers greater than 0 and less than or equal to 14

In another embodiment, the core particle material is TiN, TiCN, TiC, TiB ₂ , ZrC, ZrN, ZrB ₂ , HfC, HfN, HfB ₂ , TaB ₂ , VC, VN, cBN, hBN, Al ₂ O ₃ , From Si ₃ N ₄ , SiB ₆ , SiAlCB, B ₄ C, B ₂ O ₃ , W ₂ B ₅ , WB ₂ , WS ₂ , AlN, AlMgB ₁₄ , MoS ₂ , MoSi ₂ , MO ₂ B ₅ , and MoB ₂ Is selected.

Metalloids are elements that exist in the heat between metals and nonmetals in the periodic table. Metalloids generally include B, Si, Ge, As, Sb and Te. Po is also often considered a metalloid element. Examples of nitride metalloids are, but are not limited to, cubic boron nitride (cBN) and Si ₃ N ₄ . An example of a metalloid carbide is B ₄ C. An example of a bimetalloid compound is SiB ₆ .

Further, providing a plurality of core particles composed of one core particle material or a plurality of other core particle materials:

The core particle material is TiN, TiCN, TiC, TiB ₂ , ZrC, ZrN, ZrB ₂ , HfC, HfN, HfB ₂ , TaB ₂ , VC, VN, cBN, hBN, Al ₂ O ₃ , Si ₃ N ₄ , SiB ₆ , SiAlCB, B ₄ C, B ₂ O ₃ , W ₂ B ₅ , WB ₂ , WS ₂ , AlN, AlMgB ₁₄ , MoS ₂ , MoSi ₂ , MO ₂ B ₅ , MoB ₂ and diamond ,

Providing from 10 to 80% by weight of the intermediate layer relative to the article on the plurality of core particles:

The interlayer comprises a second compound that differs in composition from the core particle material and has a higher relative fracture toughness, wherein the second compound comprises WC, TaC, W ₂ C, and WC and W ₂ C. Selected from the group consisting of mixtures, thereby forming coated particles,

Introducing an outer layer into the coated particles:

The outer layer comprises a metal selected from the group consisting of Fe, Co, Ni and combinations thereof to form a substantially continuous outer layer in the intermediate layer, whereby a composition particle is formed,

Shaping a plurality of said compositional particles into an article;

5 to 90% by volume of the intermediate layer is added to the liquid formed from the outer layer at a constant temperature sufficient to liquefy at least a portion of the outer layer to provide an effective amount of liquid to obtain a substantially sufficient density without substantial external molding pressure. Sintering the article for a time sufficient to dissolve:

The solid portion of the intermediate layer inhibits chemical interaction of the liquid with the core particles; And

Solidifying the liquid formed from the outer and interlayers prior to significant harmful interaction of the liquid with the core particles;

Disclosed is a method of forming an article from particulate material comprising a.

The sintering temperature and sintering time should not completely dissolve the intermediate layer, but should dissolve a portion of the intermediate layer as much as possible, for example 5-50% or 50-99% dissolution of the intermediate layer. In addition, dissolution of the solid portion of the intermediate layer prevents chemistry of the liquid and the core particles.

1 is a pseudo-binary WC-Co phase diagram.

2 shows a typical TCHP sintered article.

Figure 3 is a scanning electron micrograph showing that the TCHP structure is intact even when excessive Co is included.

4 is a scanning electron micrograph showing effectively preventing the dissolution of the WC layer during and after sintering.

5 shows a model of another TCHP material at various sintering temperatures. This compares particle dissolution under various liquid sintering conditions.

6 is a table of WC-Co solid and liquid phase compositions calculated at various temperatures and cobalt content.

7 is a microstructure picture of TCHP sintered liquid phase.

The present disclosure provides a method that enables the design of existing impossible material-physical combinations by encapsulating and sintering fine particles comprising desired properties with tissue boundary modifiers of different properties. The TCHP building block particles contain elements such as hardness + wear resistance + toughness + binder metal + other designed physical properties, and have thousands of properties designed for simultaneous optimization at the nano-, micro-, macro- and functional levels. To provide the design of new materials.

The combination of sintering and nanoencapsulation of the fine particles creates a pseudoalloy structure with material phases and properties that are not thermodynamically incompatible. Such bonding allows for manipulating these phases and properties, for example, as a complex composition at the working surfaces and edges of the tool and as a thermally introduced coating. For example, a combination of a plurality of physical properties, such as light weight, low coefficient of friction, low / high thermal conductivity, slippage and lubrication, is achieved without the traditional limitations associated with alloying, lamination, improvement of mechanical properties and heat treatment.

The method described herein involves the formation of an article from particulate material. For example, the particulate material or TCHP includes a plurality of core particles, an intermediate coating on most of the particles and an outer layer coating on the particles.

In a powdered embodiment, the core particle is one core particle material or a plurality of other core particles, for example selected from nitrides, carbides, carbon nitrides, borides, oxides, sulfides, silicates or diamonds of metals or metalloids. It may be a unique composite particulate material composed of a material. The core particle material is a compound having a chemical formula of M _a X _b , wherein M is selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Mg, Cu, B and Si Metal; X is at least one element selected from nitrogen, carbon, boron, sulfur, silicon and oxygen.

The letters a and b in the formula M _a X _b are integers greater than 0 and not more than 14. Examples of such compounds are TiN, TiCN, TiC, ZrC, ZrN, VC, VN, Al ₂ O ₃ , Si ₃ N ₄ , SiB ₆ , SiAlCB, W ₂ B ₅ , AlN, AlMgB ₁₄ , MoS ₂ , MoSi ₂ , Mo ₂ B, and MO ₂ B, but are not limited to these compounds. In yet another embodiment, the plurality of core particles comprises at least one particle selected from diamond, equiaxed boron nitride and hexagonal boron nitride and mixtures thereof or any of the materials mentioned above.

As used herein, "selected" means an individual composition or a combination of two (or two or more) compositions. For example, X may comprise only one of nitrogen, carbon, boron, sulfur, silicon and oxygen or X may comprise a mixture of any or all of these compositions.

In another embodiment, the plurality of particles comprises an intermediate layer comprising WC, W ₂ C, tool steel, glassy or glassy nanosteel alloy, silicon nitride, or tantalum carbide. Include. Such materials have higher fracture toughness than equiaxed boron nitride. However, the interlayer material can be combined with the metal compound or the material forming the core particles, and Fe, Co. In addition to being able to form bonds with metals selected from Ni, Cu, Ti, Al, Mg, Li, Be, Ag, Au and Pt, they also need to have higher relative fracture toughness than materials containing core particles. have.

In one embodiment, but not limited to, the coated particles have an average particle size of less than about 1000 μm. In another embodiment, the coated particles may have an average particle size of less than about 100 μm and may have an average particle size of less than 2 μm, for example less than 1 μm, for example less than 50 μm. In yet another embodiment, the coated particles can have an average particle size of 100 to 1000 nm.

In other embodiments, the interlayer, which is not limited thereto, may have a thickness in the range of 5-50% of the core particle diameter after sintering. The thickness of the intermediate layer affects the mechanical properties of the articles made therefrom. In one embodiment, the sintered article is formed when the coated particles (cores having an intermediate layer thereon) are less than about 2 μm in mean particle diameter, which are graphically measured in a micrograph of the cross section using the mean free path method. The resistance to dislocation movement is improved while improving the mechanical properties of c). Even when using the classical mechanical approach, using finite element analysis, an increase in the thickness of the WC of the spherical shell surrounding TiN spheres of about 0.1 to about 0.4 μm increases the theoretical toughness by more than 40%. When the WC, TaC, W ₂ C, or WC and W ₂ C coatings decrease below about 150 nm, image stress begins to gradually increase fracture toughness much more than predicted by finite element analysis. It is believed that Acta Metallurgica, Vol. 33, No. 1, p. As N. Louat said in 59-69 (1985), image stresses are defined as intrinsic Newtonian resistance in the dislocation glide of microstructures.

Such intermediate layers may be chemically deposited, physically deposited, plasma deposited, laser cladding or deposition processes, plasma cladding, magnetic field plasma deposition, electrochemical plating, electroless plating, sputtering, solid phase It may be deposited by at least one method selected from a synthetic solution chemical vapor deposition process and a combination of these processes.

In one embodiment, depending on the compound (s) to be deposited, the various precursors used in the deposited compound, the layer deposition method as described above, the core particle chemistry, the interlayer thickness, and the desired properties of the coating, the interlayer is from about 20 to about 8000. It may be deposited at a temperature in the range of 20 ° C to 125 ° C. In other embodiments, the intermediate layer may be deposited at a temperature in the range of # 125 to 1800 ° C, 1800 to about 8000 ° C, and for example 200 to 800 ° C.

In another embodiment, the interlayer also comprises, for example, from 60 to 98% by weight of the article, selected from WC, TaC, W ₂ C, or WC and W ₂ C. In another embodiment, the interlayer comprises, for example, WC, TaC, W ₂ C, or a material selected from WC and W ₂ C based on 10 to 60% by weight, based on the article. In yet another embodiment, the intermediate layer comprises 5 to 10 weight percent of the article selected from WC, TaC, W ₂ C, or WC and W ₂ C.

In an embodiment, the plurality of coated TCHP particles may be encapsulated by an external binder, which may be continuous, for example. This layer may comprise cobalt, nickel, iron, mixtures thereof, alloys thereof or intermetallic compounds thereof deposited on the outer surface of the second metal compound layer. The outer layer will generally have a thickness in the range of 3 to 12% of the diameter of the coated particles after sintering. Such outer layers may further comprise at least one layer selected from other metals, ceramics, binders, sintering aids and polymeric materials.

The outer layer is at least one of chemical vapor deposition, physical vapor deposition, plasma deposition laser cladding or deposition process, plasma cladding, electric field plasma deposition, electrochemical plating, electroless plating, sputtering, solid phase synthesis, or solution chemical vapor deposition process and combinations thereof. Can be deposited by one. In one embodiment of the TCHP, the aforementioned outer layer comprises at least one compound selected from metals, ceramics, binders, sintering aids, waxes, or polymeric materials. In the case of binders, sintering aids, waxes, or polymeric materials, the coating can be accomplished by mixing or blending with or without heating in the range of < RTI ID = 0.0 > 50-150 C. < / RTI >

TCHP coatings can be deposited over a wide temperature range using a variety of processes, such as the most common CVD. The most common temperature range for CVD coating deposition is 200 to 800 ° C. However, even higher temperatures (1800 to about 8000 ° C.) are typical for processes such as plasma deposition, magnetic field plasma deposition, pulsed laser deposition and electric arc discharge. Lower temperatures (20-200 ° C.) are also typical for sol-gel solution chemistry, electrochemistry and electroless deposition.

As with the interlayer, embodiments of the various outer layers may be prepared at different temperatures depending on the compound (s) to be deposited, the various precursors used in the deposited compounds, the above-described layer deposition methods, core particle chemistry, interlayer thickness, and desired coating properties. Since it is deposited in, the outer layer can be deposited in a temperature range of 20 to 650 ℃. In one embodiment, the outer layer is deposited at a temperature range of, for example, 20 to 125 ° C. In another embodiment the outer layer is deposited at a temperature range of, for example, 125 to 650 ° C. In another embodiment the outer layer is deposited at a temperature that may range from 200 to 550 ° C., for example.

As described, the outer layer of particles after sintering usually has a thickness in the range of 3 to 12% of the diameter of the coated particles. The thickness of the outer layer may allow stress fields associated with dislocations in one coated particle to be transferred to an adjacent neighboring intermediate layer through an outer binder layer.

In one embodiment, the outer layer comprises, for example, 45% by weight of the article, for example 0.5-3.0% by weight of the article. In yet another embodiment, the outer layer comprises 3.0 to 18% by weight of the article, and in yet another embodiment, the outer layer comprises 8 to 45% by weight of the article.

The combination of core particles, intermediate layer and outer layer can form coated particles having an average particle size of about 1 μm or less, for example.

Using the above-described powders, a sintered TCHP embodiment comprising a plurality of sintered TCHP coated composite particle parameters having a plurality of core particle compounds or ureas described above has a high fracture toughness composed of a particle intermediate coating and a binder layer. It can be designed to be present at the same time in a conventional microcontinuous microstructure. It is because of the combination and combination of more than 30 different core particle compounds and urea that give the TCHP system a variety of properties with unique combinations of properties.

In general, TCHP is ultimately molded into an article or clad on an article. Molded TCHP articles are designed for a variety of applications, such as requiring maximum wear resistance and high toughness. In their shaped embodiments, TCHPs are a unique class of materials that essentially comprise various combinations of TCHP coated particles sintered into one integrated. In an embodiment, the TCHP coated particles are sintered into an article using liquid phase sintering. In one embodiment, the article is liquid sintered using cobalt as a binder phase. In another embodiment, nickel or iron or alloys of cobalt, nickel and iron may be used as the binder. Molding during this sintering process can occur mainly from capillary action.

Liquid phase sintering of TCHPs can be facilitated by several factors. One element is essentially a uniform distribution of the material including the outer layer which encloses the powder as a whole. For the purpose of describing the distribution of these substances, "uniform" means the outer layer on the surface of the intermediate layer of particles which evenly distributes the body of the compacted powder in which the outer layer material is not sintered as a whole. In an embodiment, this uniform distribution is atom-by cobalt (or other material comprising a particulate outer layer) during coating to encapsulate the surface of WC-coated TCHP particles in close proximity to the desired Co: WC ratio. -atom). This continues until the desired Co: WC ratio is evenly distributed over the TCHP particles and throughout the powder. This feature of the TCHP is adapted to suitably accommodate many other purposes of the TCHP composition, such as (a) protecting the core particles from dissolving by the binder, and (b) providing a structure giving continuous toughness. Allow the condition. While lowering the demand for high external pressure without risk of WC tissue growth and loss of strength, higher sintering temperatures are required than those of conventional WC-Co materials. In addition, the more uniform the distribution of Co, the better the uniform distribution of the core particles with microstructural consistency and wear resistance. The uniform microstructure of TCHP of this result has higher microstructural integrity. The result is lower structural defects, better and more consistent properties, and increased performance.

In an embodiment, sintering is sufficient to obtain a liquid phase in the outer layer, the intermediate layer, or the outer layer and the intermediate layer, for example, containing no volume of core particles, up to 99.5% by volume of the layer, for example up to 70% by volume, and Other examples may occur for up to 45% by volume, temperature and / or molding pressure, time.

In an embodiment, the sintering temperature may range from 600 to about 8000 ° C. In one embodiment, the sintering temperature may range from 600 to 1700 ° C., for example 1250 to 1700 ° C. According to another embodiment, the sintering temperature may be, for example, 1700 to about 8000 ° C.

According to one embodiment, which is not limited thereto, the sintering temperature may be, for example, 600 to 1700 ° C., and the liquid phase may include 6 to 44% by volume of the layer without including the core particle volume.

In general, TCHP molding occurs at pressures greater than zero, for example in the range of zero to atmospheric pressure.

Typically, the "vacuum" sintering pressure occurs in the range of 1-760 torr (760 torr = 1 atm), which is commonly referred to as "pressureless" sintering. In this case, the use of pressures below atmospheric pressure is intended to control the chemical reaction rate and the physical process at various temperature ranges used during the sintering process, which are usually two purposes. Gases include, but are not limited to, compounds associated with nitrogen, argon, helium, hydrogen, neon, krypton, xenon, methane, acetylene, carbon monoxide, carbon dioxide, and mixtures thereof.

Pressureless sintering is performed at sintering temperatures that do not form pre-fired (green) articles during cold or warm compacting processes such as cold isostatic pressing (CIP). Sintering or molding. External molding pressure is generally applied to the extent sufficient to form a green article during the compression process. It is apparent to one of ordinary skill in the art that sintering does not occur during cooling or warm compression processes.

Binders commonly used to add green strength to articles formed from the TCHP described herein include paraffin wax, stearic acid, ethylenebis-stearic acid (EBS), plasticizers (eg, Polyvinyl alcohol, polyethylene glycol, or synthetic resin) and similar organic compounds, but is not limited thereto.

TCHP core powders, such as but not limited to TiN, ZrN and HfN, nitrides react at high sintering temperatures by releasing nitrogen. Nitrogen frees the Ti element and Ti prevents the WC coating of carbon, which creates nonstoichiometric conditions that are detrimental to the mechanical properties of TCHP. Chemical TCHP reactions, which can be prevented or enhanced through the use of atmospheric pressures below atmospheric pressure, include oxidation and reduction reactions (decarbonization, deoxygenation, denitrogenation, gas release, or various compositions in the core powder or coating). Chemical decomposition). The control of the oxidation and reduction reactions is desirable for the stabilization of the sintered part and furthermore, to aid in densification.

Some TCHP core particles may be very irregularly shaped and not rounded by dissolution, thus requiring the use of lubricating oils in molding. In addition, WC and Co TCHP coatings of thin films may require additional polymeric protective coatings because they require protection from oxygen and moisture in the air. Examples of physical TCHP processes that can be controlled through the use of subatmospheric pressures include the delivery of polymeric materials (ie, the rate of debinding or delubing), the rate of volatilization, the rate of heat transfer, and the thermal decomposition of possible compositional materials. Include.

Polymeric materials are used for protective encapsulation in TCHP applications, such as variable binders and lubricants, and for improved shelf life, such as paraffin wax, stearic acid, ethylenebis-stearic acid (EBS), and plasticizers (polyvinyl alcohol). , Polyethylene glycol, or synthetic resins), and similar related organic compounds.

Pressures below atmospheric pressure are generally not used for molding purposes. The purpose of absolute pressure above atmospheric pressure is to mold the PM part. However, gas pressures above atmospheric pressure can also control the chemical reactions described above.

The volume of the liquid phase of the outer or intermediate layers can be increased by increasing at least one variable selected from, for example, the sintering temperature, the sintering pressure and the binder material content. An example of a binder material is cobalt, but is not limited thereto.

The uniform distribution of Co locally and throughout the entire TCHP object eliminates the need for high external pressures by allowing an increase in sintering temperature above the 1275 ° C eutectic point necessary to obtain the total amount of liquid phase for mass transfer and TCHP densification. Decrease.

In the sintering of TCHP, the wetting angle of the cobalt layer on the WC even at temperatures below the eutectic point is small and may be zero, for example. In one embodiment, cobalt in TCHP coated directly on the WC layer only needs to travel a very short distance to contact and wrap the WC coating. During heating of TCHP, the atoms of the outer layer in each WC layer initially diffuse and later dissolve into the outer Co layer. The WC layer dissolves uniformly from outside to inside. In TCHP this layer is in thermodynamic equilibrium and of course obtains a liquid phase with very reduced cobalt mobility.

In an embodiment, cobalt does not penetrate the coating into the core particles. For example, generally very close WC _(1-x) coating surfaces of CVD coatings can be provided on tool inserts and other articles. CVD- deposited at a deposition temperature of WC _(1-x) poly (CVD-deposited WC _(1-x) polycrystals) can be hundred times more (two orders of magnitude) more than what is found in conventional milled WC-Co particles It can be small and can be compressed harder. During stoichiometric carbonization of the WC _(1-x) coating, there is tissue growth in the coating polycrystal (depending on the carbonization temperature). However, this close proximity of the cobalt to the polycrystal allows the coated polycrystal to dissolve uniformly around the WC coating, and the equilibrium may limit tissue growth. 3 and 4, the polycrystals are shown in the WC coating structure after sintering to be one order of magnitude smaller in size than conventional milled WC-Co polycrystals. In another embodiment, about 1 μm tissue growth may occur in significant Co-pooling areas.

The barrier of TCHP WC coatings to Co attack can be at least partially described below. It is obvious that WC and Co in TCHP will be chemically and essentially behaving like WC and Co in existing hard metal blends. By evaluating the phase equilibrium of the WC-Co (FIG. 5), a typical TCHP target consisting of 50% by volume of particles (75% by weight) WC coating having a coating composition of 94% by weight WC-6% by weight Co at 1500 ° C. During sintering of the substrate, 87.1% by weight of the WC coating (ie 92.7% of the original 50% by volume WC coating) is present as a solid WC protecting the TCHP coating on the TCHP core particles. Since the WC coating dissolves from the outside to the inside, the remaining solid WCs can only be present as the desired core-protective and structural coatings.

When cobalt softens and approaches liquid phase, some particle rearrangement is expected, but rearrangement alone is insufficient to provide sufficient densification, so additional WC must be liquefied. Densification can be achieved with only very low volumes of liquid phase. Since liquid Co is uniformly distributed in TCHP without grass or slope, along almost all WC surfaces of the weaver, very low volume liquid Co binders can provide an important part of liquid sintering. It is believed that the dissolution of WC should provide the remainder of liquid phase sintering.

As noted above, when leaving the insoluble protective and structural layer around the core particles, the WC coating of TCHP particles generally dissolves from the outside and is present in the particle coating described above as a filling material for kinetic moving pores and gaps. It is reprecipitated and flocculates to strengthen it. As used herein, "interstitial filler" means a material that fills the gaps (small spaces) between adjacent particles. Only partial dissolution of the WC coating layer in the Co binder can produce a complete microstructured matrix of densification, WC reprecipitation / recrystallization and continuous TCHP. The only required Co and WC mobility is what is needed to move the material that fills the gap between the coated core particles.

In theory, there are at least three ways to increase the dissolution of the solute in the solvent: (1) increasing the amount of solvent (in one embodiment, Co: WC weight percent ratio), (2) increasing the temperature of the solvent and solute, And (3) reduction of pressure on solvents and solutes. In practice, there are only two ways to increase the amount of liquid phase during sintering of TCHPs. First, these two methods are described.

Many core particles will, for example, chemically interact with potential metal carbides and nitrides, cobalt, nickel and other binders. Such core particles are named as "soluble core" group particles. For increasing temperatures, even though the TCHP sintering temperature increases significantly enough to provide the required amount of liquid phase for the LPS, there is still a LPS-a thick WC layer that prevents cobalt from attacking “soluble cores”. 'Will protect the group particles. It should be possible to increase the temperature as high as necessary for the additional liquid phase (lubricant + crevice filler + capillary attractant) needed to achieve sufficient density while minimizing tissue growth.

For example, in one embodiment, like the 1 μm core TCHP, TiN particles having the same volume percent of WC and TiN, the initial WC coating (spherical model) is nearly 129 nm thick and about 75 weight of the total particles. Will contain%. Dissolution of WC at 1500 ° C. removes only 7.9 nm, about 6% of the coating thickness, ie 121 nm, about 94% of the original coating thickness, for core particle protection, uniformity of distance between core particles and structural toughness. Will remain.

Because of this feature of TCHP, increasing the amount of binder phase solvent by increasing the cobalt layer thickness is another sintering method that can be used according to the methods described herein. For example, an increase in the cobalt content percentage higher than conventional in WC-Co sintering can be accomplished by a method that provides the necessary dissolution, capillary action, WC kinetics and densification for TCHP. Since abrasion resistance is provided by the core particles, WC in TCHP is primarily present as a substrate material to have high performance. While simultaneously increasing fracture toughness after cooling, the added cobalt will therefore be added to the liquid phase during sintering.

Sintering can be performed by sintering press, vacuum, injection molding, plastic extrusion, hot press, hot isostatic press (HIP), sinter-HIP HIP, sintering furnace, laser cladding process, plasma cladding, high velocity oxygen-fueled (HVOF), spark plasma sintering, pressure plasma sintering sintering, pressure-transmission medium, dynamic / explosive compaction, sinter forge, rapid prototyping, electron beam, and electric arc may occur in a process selected from an electric arc.

The WC coating in TCHP protects the core particles. Firstly, during sintering, especially in the “soluble core” group, the WC coating can protect the core particles from dissolution by binder metal, and also protect the substrate from harmful contamination by, for example, TiN, ZrN, NbC. Can be. The high wear resistant TCHP core particles protect the WC-Co support matrix from abrasion after sintering, and the support substrate protects the fragile phase from fracture and pullout. 2 shows the sintered microstructure of a typical TCHP material.

The TCHP structure having a nanoscale shell with high performance separated by a small hard core particle size and a thin cobalt band of less than 1 μm between tissues, for example, improves elasticity, hardness, toughness and strength. In one non-limiting embodiment having a low hardness material (such as cobalt), the physical properties of the composite of phase stresses from dislocations near the surface are higher than are possible with abrasive composites.

According to the method described herein, TCHP provides a sinterable metal particulate material that can be designed to provide a suitable balance of properties such as toughness, strength, low coefficient of friction and hardness, for example. In one embodiment, but not limited to, manipulating improvements that can be observed in dies and other tooling made from TCHP's, for example, (a) provide reduced heat, wear and wear Less demands on the secondary use of process power and external lubrication, resulting in a lower coefficient of friction at the interface between the product and the tool for longer tool life and better process control; (b) low reactivity with iron to reduce stickiness and diffusion, reduce flank, or die wear, thereby extending the life of the drawing template; And (c) the particulate tough and tough coating material (ie WC) forms a porous flexible macrostructure suitable for the tool, while providing a protective film that is tightly coupled with the surface fit for the hard particulate core (eg TiN). It is a microstructure of a sintered tool that provides, holds them in place, and allows for hard exposure on the tool surface with proper exposure and wear resistance. The Ti-Co-WC alloy dramatically lowers the binder strength present between the particles and the binder itself lowers the level of toughness and blending strength, where the sintered article is coated entirely to give strength, where the thin coating This is in contrast to articles produced by conventional methods with limited lifetimes or cracks.

By placing the core particles inside instead of outside, the hard-phase alloys (exposed to the outer surface after polishing) are finely sintered at a rate or thickness greater than is possible with known conventional materials. Distribute throughout the structure. In essence this, for example, increases wear resistance, reduces chemical interaction with the workpiece and significantly reduces the friction constant. Tool life can be improved by continuous regeneration of surface tissues that is worn or separated by slippery surfaces.

In addition, the wear resistance and adhesion properties of many of these core materials are known from the performance of existing materials, and therefore their performance as core particle materials is predictable in view of the present disclosure. In an embodiment that is not limited thereto, since the core particles are coated with a known material (ie, WC), blending and sintering the coated material having several different core materials promotes the improvement of various physical properties. Thus, while providing a final material with unique properties, improvements and test costs are reduced. In addition, designing a sintered microstructure that has a tough shell (intermediate layer) so that each particle strongly adheres to neighboring particles, thereby producing a tough porous structure generally on the sintered article substrate, is a strength. It provides a sintered article having high modulus of elasticity, fracture toughness and hard alloy content.

In accordance with an embodiment, the resulting microstructure of the article is a porous microstructure backbone comprising tough, strength, tightly bonded coated particle shells. Here, the coated particle shell comprises at least one material selected from mechanically and chemically bound core particles, crystals, fibers and whiskers and is exposed in cross section to the outer surface during polishing and polishing. The principle of optimizing the combination of other materials of the core particles with the surrounding interlayers provides a combination of performance characteristics of commonly incompatible articles such as strength and hardness, which are not obtainable in conventional materials.

This concept can give material designers a variety of tools that can be used individually or in combination, and many other unique, combined and special features such as TCHP particle structure (intermediate layer thickness, size and core material) and unique articles or tools. In adopting the requirements mix (integrating other powders into tools and article areas), it can be used in the right way to provide easy and total control.

In addition, the strength that is referred to as a tough outer particle shell is because only one material reactant precursor gas (eg tungsten carbide) is used to coat the powder particles in place of many complex precursors and reaction gases used in various outer substrate coatings. The use of certain substances (eg WC) dramatically reduces research, development and mass production efforts. This particular material will be sintered as if made of, for example, tungsten carbide particles, which are already known to bind very tightly with a binder such as cobalt and neighboring tungsten carbide particles. The tungsten carbide coating thickness on the particles can be increased, for example, to meet even more challenging strength applications and can also be reduced, for example, in critical wear applications to solve most design tests. For example, the core particle size can be easily increased to meet even more stringent requirements for wear resistance and can also be reduced for higher strength applications. The use of other core particles with known hardness and coefficient of friction properties for better performance in special applications such as flank wear or crater wear may be achieved by the choice of core material. It is also possible to blend the thickness, diameter, and core material powder coefficients described above to address most of the various standard applications.

It will be appreciated by those skilled in the art that changes may be made from the above-mentioned embodiments without departing from their broad inventive concept. Thus, the present invention is not limited to the particular embodiments disclosed and is willing to embrace variations that are within the scope and spirit of the invention as defined by the claims.

Unless indicated otherwise, it is to be understood that the terms used in the components, reaction conditions, specifications and claims will be modified in all instances by the term “about”, which means average +/- 5% of the expressed number. . Accordingly, unless indicated to the contrary, the number of numbers described in the following specification and claims are approximations that may vary depending on the desired physical properties sought to be obtained by the present invention.

Articles made from TCHP particles are classified as articles of combined properties that cannot be countered in conventional materials, such as strength, hardness, high modulus of elasticity, fracture toughness, low interaction with work parts and low friction Combine the best mechanical properties of the modulus. TCHPs have practically unlimited use in production, surface modification or repair of components, assemblies and machinery. One group includes cutting, forming, grinding, measuring, petroleum and minerals, and construction machinery. Nontool components include biomedical, military, electronics, sports, thermal management, and cosmetic applications. A wide range of industrial applications can be found in agriculture, urban engineering, timber and paper, petrochemicals, rubber and plastics, transportation, aircraft / aerospace, maritime, architecture and energy. Such materials are therefore well suited for a wide variety of uses of articles. E.g:

Wire drawing dies, extrusion dies, forging dies, cutting and stamping dies, forms, forming rollers, injection molding molds, shears, drills, milling and lathe cutters, saws, hobs, broaches, juicer reamers, taps and Taps and dies;

Individual machine parts as gears, cams, bearing journals, nozzles, seals, valve seats, pump impellers, capstans, shelves, bearings and wear surfaces on the shaft ;

Mating parts internal combustion engine connecting rods, for replacing bearings and / or

Provides a hard surface area in powder metal (P / M) machine parts that are replaced for forged or mechanical metal parts powder with heat treated parts as camshafts, transmission parts, printer / copier parts Integrated co-sintered components;

Heavy industrial articles such as deep well drilling bits, teeth for mining and earthmoving equipment, hot rolls for steel mills ); And

Electromechanical components such as memory drives that read heads and special magnets.

The fact that the molded TCHP article is macroscopically homogeneous rather than externally coated may provide the user or provider with the opportunity to economically regrind or reuse the initial worn out article. This is particularly important for tools such as wire drawing dies, twist drills, milling cutters, and water jet nozzles.

Claims (47)

A method of making an article comprising a composition particle composed of a core particle, an intermediate layer and an outer layer, Metal nitrides and metalloids, metal carbides and metalloids, metal carbides and metalloids, metal borides and metalloids, metal oxides and metalloids, metal oxides and metalloids, metal sulfides, metal silicides And providing a plurality of core particles composed of one core particle material or a plurality of other core particle materials selected from the group consisting of metalloid silicides and diamonds: Depositing, on an atomic scale, an intermediate layer of 10 to 80% by weight of the article on the plurality of core particles, the intermediate layer being different from the core particle material in composition and having a higher relative fracture toughness Wherein the second compound is capable of binding to the core particle material and selected from the group consisting of Fe, Co, Ni, Cu, Ti, Al, Mg, Li, Be, Ag, Au, Pt and combinations thereof Providing an intermediate layer capable of combining the metal with which the particles are coated: Depositing a metal selected from the group consisting of Fe, Co, Ni, and combinations thereof on the coated particles on an atomic scale to introduce an outer layer continuous with the intermediate layer, thereby forming composition particles: Shaping a plurality of said compositional particles into an article; The shaped article is sintered for a time sufficient to dissolve a portion of the intermediate layer in the liquid formed from the outer layer at a temperature sufficient to liquefy at least a portion of the outer layer to provide an amount of liquid effective to obtain sufficient density. Wherein the sintering temperature is from 600 to 1700 ° C. and the article is prepared such that the liquid phase consisting of the outer layer, the middle layer or a mixture thereof is 6 to 44% by volume of the compositional particles, excluding the core particle volume. Sintering; And Solidifying the liquid formed in the outer layer and the intermediate layer such that the atoms deposited to form the intermediate layer re-precipitate into the substrate outside the undissolved portion of the intermediate layer, wherein the substrate separates the crystals separated from the intermediate layer within the binder of the outer layer. And solidifying a liquid formed from the outer and intermediate layers prior to chemical interaction of the liquid with the core particles. A method of forming an article comprising a. The method of claim 1, Wherein said core particle material forms an article having the formula M _a X _b : Wherein M is a metal selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Mg, Cu, and Si; X is an element selected from nitrogen, carbon, boron, sulfur, and oxygen; a and b are integers greater than 0 and less than or equal to 14 The method of claim 1, The core particle material is TiN, TiCN, TiC, TiB ₂ , ZrC, ZrN, ZrB ₂ , HfC, HfN, HfB ₂ , TaB ₂ , VC, VN, cBN, hBN, Al ₂ O ₃ , Si ₃ N ₄ , SiB ₆ , SiAlCB, B ₄ C, B ₂ O ₃ , W ₂ B ₅ , WB ₂ , WS ₂ , AlN, AlMgB ₁₄ , MoS ₂ , MoSi ₂ , MO ₂ B ₅ , MoB ₂ And combinations thereof. A method of making an article comprising a composition particle composed of a core particle, an intermediate layer and an outer layer, TiN, TiCN, TiC, TiB2, ZrC, ZrN, ZrB ₂ , HfC, HfN, HfB ₂ , TaB ₂ , VC, VN, cBN, hBN, Al ₂ O ₃ , Si ₃ N ₄ , SiB ₆ , SiAlCB, B ₄ One or more core particle materials selected from the group consisting of C, B ₂ O ₃ , W ₂ B ₅ , WB ₂ , WS ₂ , AlN, AlMgB ₁₄ , MoS ₂ , MoSi ₂ , MO ₂ B ₅ , MoB ₂ and diamond Providing a plurality of core particles composed of different core particle materials of: Depositing, on an atomic scale, an intermediate layer of 10 to 80% by weight of the article on the plurality of core particles, the intermediate layer being different from the core particle material in composition and having a higher relative fracture toughness Wherein the second compound is capable of binding the core particle material and coating the particles in combination with a metal selected from the group consisting of WC, TaC, W ₂ C, and a mixture of WC and W ₂ C. Providing the middle layer: Depositing a metal selected from the group consisting of Fe, Co, Ni, and combinations thereof on the coated particles on an atomic scale to introduce an outer layer continuous with the intermediate layer, thereby forming composition particles: Shaping a plurality of said compositional particles into an article; An amount effective to sinter the shaped article at a temperature sufficient to liquefy at least a portion of the outer layer for a time sufficient to dissolve 5-40% by volume of the intermediate layer in the liquid formed from the outer layer, thereby obtaining a sufficient density Wherein the sintering temperature is from 600 to 1700 ° C. and the liquid phase consisting of the outer layer, the middle layer, or a mixture thereof is comprised between 6 and 44% by volume of the composition particles, excluding the core particle volume. Sintering the article to become; And Solidifying the liquid formed in the outer layer and the intermediate layer such that the atoms deposited to form the intermediate layer re-precipitate into the substrate outside the undissolved portion of the intermediate layer, wherein the substrate separates the crystals separated from the intermediate layer within the binder of the outer layer. And solidifying a liquid formed from the outer and intermediate layers prior to chemical interaction of the liquid with the core particles. A method of forming an article comprising a. The method according to any one of claims 1 to 3, Wherein the sintering temperature and sintering time form an article in which complete dissolution of the intermediate layer does not occur. The method according to any one of claims 1 to 3, Wherein said sintering temperature and said sintering time are 5 to 50% dissolution of said intermediate layer. 4. The method according to any one of claims 1 to 3, Wherein said sintering temperature and said sintering time are 50 to 99% of said intermediate layer dissolved. 4. The method according to any one of claims 1 to 3, Wherein said solid portion of said intermediate layer prevents chemistry of said liquid and said core particles. 4. The method according to any one of claims 1 to 3, The interlayer comprises a material selected from the group consisting of WC, W ₂ C, tool steel, glassy and devitrified nanosteel alloys, silicon nitride and tantalum carbide. And forming an article. The method according to any one of claims 1 to 4, Wherein the coated particles form an article having an average particle size of 1000 μm or less. The method according to any one of claims 1 to 4, Wherein the coated particles have an average particle size of 100 μm or less. The method according to any one of claims 1 to 4, Wherein the coated particles have an average particle size of 50 μm or less. 5. The method according to any one of claims 1 to 4, Wherein the coated particles have an average particle size of 2 μm or less. 5. The method according to any one of claims 1 to 4, Wherein the coated particles have an average particle size of 1 μm or less. 5. The method according to any one of claims 1 to 4, And wherein the coated particles have an average particle size of 100 to 1000 nm. 5. The method according to any one of claims 1 to 4, Wherein said intermediate layer has a thickness of 5 to 50% of the diameter of said core particles after sintering. 5. The method according to any one of claims 1 to 4, Wherein the outer layer has a thickness of 3 to 12% of the diameter of the coated particles after sintering. 5. The method according to any one of claims 1 to 4, Wherein said outer layer further comprises one or more layers of material selected from the group consisting of metals, ceramics, binders, sintering aids and polymeric materials. 5. The method according to any one of claims 1 to 4, The intermediate layer may include chemical vapor deposition, physical vapor deposition, plasma deposition, laser cladding or deposition process, plasma cladding, magnetic plasma deposition, electrochemical plating, electroless plating, sputtering, solid phase synthesis, A method of forming an article, provided by at least one method selected from the group consisting of a solution chemical vapor deposition process and combinations thereof. 5. The method according to any one of claims 1 to 4, The outer layer is chemical vapor deposition, physical vapor deposition, plasma deposition, laser cladding or deposition process, plasma cladding, magnetic plasma deposition, electrochemical plating, electroless plating, sputtering, solid phase synthesis, A method of forming an article, provided by at least one method selected from the group consisting of a solution chemical vapor deposition process. 5. The method according to any one of claims 1 to 4, Wherein said intermediate layer is formed at a temperature of from 125 to 1800 ° C. 5. The method according to any one of claims 1 to 4, Wherein said intermediate layer is formed at a temperature of from 20 to 125 ° C. 5. The method according to any one of claims 1 to 4, Wherein said intermediate layer is formed at a temperature of 1800 to 8000 ° C. 5. The method according to any one of claims 1 to 4, Wherein said intermediate layer is formed at a temperature of 200 to 800 ° C. 5. The method according to any one of claims 1 to 4, Wherein said outer layer is formed at a temperature of from 20 to 125 ° C. 5. The method according to any one of claims 1 to 4, Wherein said outer layer is formed at a temperature of from 125 to 650 ° C. 5. The method according to any one of claims 1 to 4, Wherein said outer layer is formed at a temperature of between 200 and 550 ° C. 18. 5. The method according to any one of claims 1 to 4, And wherein said sintering temperature is between 600 and 1275 ° C. 5. The method according to any one of claims 1 to 4, Wherein said sintering temperature is greater than 1275 ° C. and less than 1700 ° C. 5. The method according to any one of claims 1 to 4, Wherein said outer layer comprises 0.5 to 3 weight percent of said article. 5. The method according to any one of claims 1 to 4, Wherein the outer layer comprises 3 to 18 weight percent of the article. 5. The method according to any one of claims 1 to 4, Wherein said outer layer comprises 18 to 45 weight percent of said article. 4. The method according to any one of claims 1 to 3, Wherein said interlayer comprises from 60 to 98% by weight of said article comprising a material selected from the group consisting of WC, TaC, W ₂ C, WC, and W ₂ C. 4. The method according to any one of claims 1 to 3, Wherein said intermediate layer comprises from 10 to 60% by weight of said article comprising a material selected from the group consisting of WC, TaC, W ₂ C, WC, and W ₂ C. 4. The method according to any one of claims 1 to 3, Wherein said intermediate layer comprises from 5 to 10% by weight of said article comprising a material selected from the group consisting of WC, TaC, W ₂ C, WC, and W ₂ C. delete delete 5. The method according to any one of claims 1 to 4, Sintering molding is a method of forming an article that is primarily caused by capillary forces. delete 5. The method according to any one of claims 1 to 4, The volume of the liquid phase is increased by increasing at least one variable selected from the sintering temperature and the content of Co. 5. The method according to any one of claims 1 to 4, Wherein the forming is carried out in a gas atmosphere selected from nitrogen, argon, helium, hydrogen, neon, krypton, xenon, methane, acetylene, carbon monoxide, carbon dioxide and combinations thereof. The method of claim 40, Wherein said process gas is provided at an absolute zero atmosphere to atmospheric pressure. 5. The method according to any one of claims 1 to 4, The method of forming the article is selected from a plurality of the composition particles and paraffin waxes, stearic acid, ethylene bis-steramide (EBS), polyvinyl alcohol and polyvinyl glycol before or simultaneously with the shaping step. Further comprising mixing at least one additive. A method of making an article comprising a composition particle composed of a core particle, an intermediate layer and an outer layer, TiN, TiCN, TiC, TiB2, ZrC, ZrN, ZrB ₂ , HfC, HfN, HfB ₂ , TaB ₂ , VC, VN, cBN, hBN, Al ₂ O ₃ , Si ₃ N ₄ , SiB ₆ , SiAlCB, B ₄ One or more core particle materials selected from the group consisting of C, B ₂ O ₃ , W ₂ B ₅ , WB ₂ , WS ₂ , AlN, AlMgB ₁₄ , MoS ₂ , MoSi ₂ , MO ₂ B ₅ , MoB ₂ and diamond Providing a plurality of core particles composed of different core particle materials of: Depositing, on an atomic scale, an intermediate layer of 10 to 80% by weight of the article on the plurality of core particles, the intermediate layer being different from the core particle material in composition and having a higher relative fracture toughness Wherein the second compound is capable of binding the core particle material and coating the particles in combination with a metal selected from the group consisting of WC, TaC, W ₂ C, and a mixture of WC and W ₂ C. Providing the middle layer: Depositing a metal selected from the group consisting of Fe, Co, Ni, and combinations thereof on the coated particles on an atomic scale to introduce an outer layer continuous with the intermediate layer, thereby forming composition particles: Shaping a plurality of said compositional particles into an article; An amount effective to obtain sufficient density by sintering the shaped article at a temperature sufficient to liquefy at least a portion of the outer layer for a time sufficient to dissolve 5 to 90% by volume of the intermediate layer in the liquid formed from the outer layer Wherein the sintering temperature is from 1700 to 8000 ° C. and the liquid phase consisting of the outer layer, the middle layer, or a mixture thereof is comprised between 6 and 44% by volume of the composition particles, excluding the core particle volume. Sintering the article to become; And Solidifying the liquid formed in the outer layer and the intermediate layer such that the atoms deposited to form the intermediate layer re-precipitate into the substrate outside the undissolved portion of the intermediate layer, wherein the substrate separates the crystals separated from the intermediate layer within the binder of the outer layer. And solidifying a liquid formed from the outer and intermediate layers prior to chemical interaction of the liquid with the core particles. A method of forming an article comprising a. The method of claim 1, wherein the sintering temperature is above 1315 ° C. 3. The method of claim 1, wherein the sintering temperature is greater than 1400 ° C. 3. The method of claim 1, wherein said sintering temperature is above 1500 ° C. 3.

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