Abstract: The present invention relates to a sintered body for chip forming machining containing at least one hard constituent comprising a carbide, nitride and/or carbonitride of a metal of group IVB, VB or VIB in the periodical system and a binder metal based upon Co, No and/or Fe, in which the body comprises a core containing eta-phase or an intermediate phase, substantially free of carbon and/or nitrogen surrounded by a hard constituent- and binder phase-containing surface zone, free of said eta-phase or intermediate phase.

Abstract: A wear-resistant sintered iron-based alloy and a process for producing the alloy are described, wherein the alloy comprises a first phase having a martensite composition which comprises from 0.5 to 3.0 wt % of Cr, from 0.4 to 1.0 wt % of Mn, from 0.1 to 0.4 wt % of Mo, and the balance of Fe, based on the total amount of said first phase; a second phase having a martensite and Cr carbide composition which comprises from 10 to 20 wt % of Cr and the balance of Fe, based on the total amount of said second phase; and from 1.0 to 2.5 wt % of C, based on the total amount of said alloy; wherein said first phase and said second phase are present as a mixture containing from 10 to 80% by volume of said second phase, based on the total volume of said alloy; and said alloy is substantially free from any residual austenite.

Abstract: An Fe-base sintered alloy for valve seats for use in internal combustion engines and a method of manufacturing the same are provided. The alloy consists essentially of 0.6 to 1.3% C, 1 to 5% Cr, 4 to 15% Mo, 0.5 to 2% Ni, 2 to 8% Co, 0.2 to 2% Nb, 0.2 to 2% at least one lubricating component selected from the group consisting of a CaF.sub.2 and BaF.sub.2 and the balance of Fe and inevitable impurities. Starting powders are blended into the same composition as above, and mixed into a mixed powder. The mixed powder is pressed into a green compact. Then, the green compact is presintered, hot forged, sintered, and, if required, further heat treated, in sequence to be formed into an Fe-base sintered alloy having a structure wherein particles of the at least one lubricating component and hard particles of other components are dispersed in a matrix formed principally of a pearlite phase. The resulting alloy possesses a density of at least 7.3 g/cm.sup.

Abstract: A cemented carbide cutting tool substrate has enhanced surface toughness due to binder enrichment and depletion of aluminum nitride near the peripheral surface.

Abstract: The present invention relates to a cemented carbide body, preferably for rock drilling, mineral cutting and wear parts, in which the content of binder phase in the surface is lower and in the center higher than the nominal content. In the center there is a zone having a uniform content of binder phase. The WC grain size is uniform throughout the body.

Abstract: The present invention is characterized by ceramic materials comprising ceramic sintered bodies consisting of (1) 1-90 wt % chromium carbide and the remainder carbonic titanium nitride; (2) 1-90 wt % chromium carbide, 0.1-5 wt % B.sub.4 C and the remainder titanium carbo-nitride; or (3) either of the above compositions plus less than 95 wt % of a metal boride such as Ti or Zr. Such ceramic sintered bodies are used for cutting tools or wear-resistant machine parts because of their high density, high hardness and high strength.

Abstract: An abrasion resistant alloy sintered in a liquid phase, which contains, by weight, 1.5 to 4.0% C, 0.5 to 1.2% Si, 1.0% or less Mn, 2.0 to less than 20.0% Cr, 0.5 to 2.5% Mo, 0.2 to 0.8% P, and the balance of Fe. The alloy is suitable for fabricating sliding parts in internal combustion engines, such as valve mechanisms.

Abstract: A vanadium-containing power tool steel is disclosed. The steel is compacted to full density at high temperature and presence and contains M.sub.6 C or M.sub.7 C.sub.3 carbides. The carbides have an effective maximal size of 4 to 15 microns.

Abstract: A wear resistant iron-base sintered alloy consists essentially of at least one selected from the group consisting of molybdenum and tungsten, ranging from 5 to 20% by weight, chromium ranging from 2 to 10% by weight, silicon ranging from 0.1 to 0.9% by weight, manganese ranging not more than 0.7% by weight, phosphorus ranging not more than 0.05% by weight, carbon ranging from 0.1 to 0.8% by weight, boron ranging from 0.5 to 2.0% by weight, and balance including iron and an impurity, so that fine multiple carbide, multiple boride, and/or multiple carbide-boride can be homogeneously dispersed as hard grains in the structure of a matrix, thereby exhibiting excellent wear resistance, scuffing resistance and pitting resistance.

Abstract: A powder-metallurgy alloy article having a good combination of wear resistance and corrosion resistance. The article is further characterized by an attainable minimum hardness after heat treatment of 60R.sub.c and a martensitic structure. The article is made from prealloyed particles of the composition, in percent by weight, carbon 2.5-5, manganese 0.2-1, phosphorus 0.10 maximum, sulfur 0.10 maximum, silicon 1 maximum, nickel 0.5 maximum, chromium 15-30, molybdenum, 2-10 vanadium 6-11, nitrogen 0.15 maximum and balance, iron. The article has a fine, uniform distribution of a MC and other carbide phases.

Abstract: A sintered hard metal having superior toughness and superior hardness may be used for micro-drills, tools and wear resistant parts. The metal is a cemented carbide WC formed from tungsten carbide WC as the base alloy and containing 4 to 20 percent by weight of vanadium carbide VC or zirconium nitride. Its micro-structure is that the WC or WC-VC particles are 0.6.mu. or less, its Rockwell Hardness HRA is at least 91.5 and its transverse rupture strength is at least 350 kg/mm.sup.2.

Abstract: Wear resistant articles, especially valve seat inserts for internal combustion engines, are produced as sintered metal compacts comprising interspersed microzones of prealloyed austenitic stainless steel and softer ferrous metal, the microzones of austenitic stainless steel containing carbides and carbonitrides. The sintered compacts can be made by forming a green compact from prealloyed austenitic stainless steel powder atomizate blended with softer powdered ferrous metal component and powdered carbon, and sintering the green compact.

Abstract: A light weight and high strength aluminum alloy and a process for producing such an alloy, which alloy is suitable for forming automotive engine components, including pistons. In a preferred embodiment, 80 to 99.5% by volume of an aluminum alloy powder or a mixed powder composed of pure metal powders or master alloy powders is blended with 0.5 to 20% by volume of at least one of carbon or graphite powder, an oxide powder, a carbide powder and a nitride powder. The blend is then mechanically alloyed, following which the thereby-obtained powder is subjected to working such as by compaction and hot forging, hot pressing, cold isostatic pressing and hot forging, or cold isostatic pressing and hot extrusion.

Abstract: A method of producing a sintering powder made from high speed steel and alumina. This sintering powder is sinterable over a broader range of temperatures than conventional high speed steel sintering powders and at lower temperatures, thereby making sintered objects which are crack resistant and also highly wear resistant. Additionally, the sintering powder flows readily when poured into a mold for production of a green object for sintering.

Abstract: A solid particle erosion resistant coating includes angular titanium carbide particles uniformly dispersed through a high chromium iron matrix. In one form, the aggregate comprises, by weight, about 30-50% TiC, about 10-30% Cr, about 1.5-5% C and the balance essentially iron in the form of ferrite. The matrix also includes metallurgically identifiable amounts of high chromium content M.sub.7 C.sub.3 carbides therethrough. The coating does not exhibit austenitic or martensitic structure therethrough. A powder alloy consolidated body also includes a surface adjacent region having a similar TiC and high chromium iron matrix. Further, a method for obtaining the coating includes heating above the austenitization temperature of the matrix alloy and below the melting temperature of iron, and cooling the aggregate so as to attain iron in the form of ferrite in the matrix.

Abstract: There is disclosed a sintered alloy for decoration comprising2 to 30% by weight of a binding phase comprising one or more elements selected from the group consisting of Fe, Ni, Co, Cr, Mo and W;0 to 10% by weight of a strengthening phase comprising one or more material selected from the group consisting of a metal, an alloy, a metal oxide, a metal nitride and a metal carbide;the balance of a hard phase represented by the formula:(Tia, Mb) (Nw, Cx, Oy)z(wherein M, A, b, w, x, y and z are defined in the specification); andinevitable impurities.The sintered alloy for decoration according to this invention possesses both a decorativeness suitable for decorative members as well as excellent corrosion resistance and mechanical properties.

Abstract: Wear-resistant, sintered iron alloys are provided. The alloys have a structure in which iron-based hard particles having a relatively high Cr content and copper or copper alloy particles are dispersed in an iron alloy matrix containing a relatively low content of Cr. The alloys are prepared by compression molding powders of the matrix alloy, the hard alloy, copper or copper alloy, an Fe-P alloy and graphite and sintering the obtained molding at a temperature of 980.degree. to 1130.degree. C.

Abstract: A wear resistant sintered alloy consisting essentially of from 2.0% to 3.5% by weight of C, from 0.3% to 0.8% by weight of P, from 0.5% to 3.0% by weight of Mn and remainder Fe. The alloy is sintered in the liquid-phase.

Abstract: A cBN sintered compact for an end mill obtained by sintering mixed powder prepared by mixing about 35 to 50 percent by volume of cubic boron nitride powder smaller than about 2 .mu.m in average particle size with about 50 to 65 percent by volume of a binder under cBN-stable superhigh pressure conditions. The binder contains about 20 to 30 percent by weight of Al and one or more Ti compounds selected from a group of TiN.sub.z, Ti(C,N).sub.z, TiC.sub.z, (Ti,M)C.sub.z, (Ti,M) (C,N).sub.z and (Ti,M)N.sub.z (where M indicates a transition metal element of the group IVa, Va or VIa of the periodic table excepting Ti and z is within a range of about 0.7.ltoreq.z.ltoreq. about 0.

Abstract: A sintered tungsten carbide material and method for manufacturing same in which the method includes the steps of combining metal particles composed of from 75 to 95 percent by weight of a composition containing at least 70 percent by weight of tungsten carbide and from 5 to 25 percent by weight of a binder metal composition, the binder metal composition consisting essentially of from 5 to 15 percent by weight of chromium and from 85 to 95 percent by weight of nickel; pressing the metal particles into a pressed body; sintering the pressed body in a sintering chamber for a period ranging from 20 to 200 minutes, at a temperature ranging from 1400.degree. to 1500.degree. C., and in a protective atmosphere which is one of a vacuum, a noble gas, a mixture of noble gases, and hydrogen gas to form a sintered body; and treating the sintered body for a period ranging from 20 to 200 minutes, at a temperature ranging from 1300.degree. to 1400.degree. C.

Abstract: Cams which meet all strength requirements and can be shrunk on a shaft can be made in a simple manner by sintering from a nickel- and copper-free mixture which comprises iron powder and contains 0.3 to 1.0 weight percent carbon and molybdenum and/or tungsten in such amounts that the sum of the molybdenums content and the tungsten content multiplied with the ratio of the atomic weight of molybdenum to the atomic weight of tungsten lies between 0.5 and 3 weight percent.

Abstract: This invention relates to a hard alloy comprising two phases: a hard phase consisting of at least one compound having a crystal structure of simple hexagonal MC type (M: metal; C: carbon) selected from the group consisting of mixed carbides, carbonitrides and carboxynitrides of molybdenum and tungsten, and a binder phase consisting of at least one element selected from the group consisting of iron, cobalt and nickel. The hard phase is prepared by carburizing an (Mo, W) alloy obtained by reducing oxides of molybdenum and tungsten with a particle size of at most 1 micron, is composed of coarse particles with a mean particle size of at least 3 microns, and has a uniform molybdenum to tungsten ratio in the particles. The hard alloy has a gross composition within the range of the shaded portion ABCDEA in FIG. 1.

Abstract: A method of manufacturing a cermet having high toughness and high hardness, which exhibits excellent impact resistance and wear resistance when used in cutting tools. A mixed powder is prepared which consists essentially of: titanium nitride, from 25 to 50 percent by weight; titanium carbide, from 10 to 30 percent by weight; at least one selected from the group consisting of tantalum carbide, niobium carbide, and zirconium carbide, from 5 to 25 percent by weight; tungsten carbide, from 10 to 25 percent by weight; and at least one selected from the group consisting of Co and Ni, and Al if required, from 7.5 to 25 percent by weight in total. The above mixed powder is compressed into a green compact. The green compact is sintered in a nitrogen atmosphere under a pressure within a range from 0.1 to 100 torr, and at a temperature within a range from 1400.degree. to 1550.degree. C.

Abstract: A solid particle erosion resistant coating includes angular titanium carbide particles uniformly dispersed through a high chromium iron matrix. In one form, the aggregate comprises, by weight, about 30-50% TiC, about 10-30% Cr, about 1.5-5% C and the balance essentially iron in the form of ferrite. The matrix also includes metallurgically identifiable amounts of high chromium content M.sub.7 C.sub.3 carbides therethrough. The coating does not exhibit austenitic or martensitic structure therehthough. A powder alloy consolidated body also includes a surface adjacent region having a similar TiC and high chromium iron matrix. Further, a method for obtaining the coating includes heating above the austenitization temperature of the matrix alloy and below the melting temperature of iron, and cooling the aggregate so as to attain iron in the form of ferrite in the matrix.

Abstract: Cemented carbide substrates having substantially A or B type porosity and a binder enriched layer near its surface are described. A refractory oxide, nitride, boride, and/or carbide coating is deposited on the binder enriched surface of the substrate. Binder enrichment is achieved by incorporating Group IVB or VB transition elements. These elements can be added as the metal, the metal hydride, nitride or carbonitride.

Abstract: Hard, tough, lightweight boron-carbide-reactive metal composites, particularly boron-carbide-aluminum composites, are produced. These composites have compositions with a plurality of phases. A method is provided, including the steps of wetting and reacting the starting materials, by which the microstructures in the resulting composites can be controllably selected. Starting compositions, reaction temperatures, reaction times, and reaction atmospheres are parameters for controlling the process and resulting compositions. The ceramic phases are homogeneously distributed in the metal phases and adhesive forces at ceramic-metal interfaces are maximized. An initial consolidation step is used to achieve fully dense composites. Microstructures of boron-carbide-aluminum cermets have been produced with modulus of rupture exceeding 110 ksi and fracture toughness exceeding 12 ksi.sqroot.in. These composites and methods can be used to form a variety of structural elements.

Abstract: The alloy of the invention comprises 75 to 90% by weight of a mixture of carbides, for example WC and TiC, and 10 to 25% of a binder. This binder comprises Co, Ni and Ru, representing together 7 to 15% of the alloy, as well as Mo.sub.2 C. This alloy is useful for the production of decorative articles having a density similar to that of stainless steel.

Abstract: A powder alloy sheet including powders of wear-resistant eutectic alloy in a quantity of 85 to 97% in volume, and acrylic resin binder in a quantity of 15 to 3% in volume.There is also disclosed a method for forming a wear-resistant layer on a workpiece comprising steps of providing a powder alloy sheet comprised on 85 to 97 vol. % of powders of wear-resistant eutectic alloy and 15 to 3 vol. % of acrylic resin binder, bonding the sheet on a workpiece surface, heating the workpiece under a non-oxidizing atmosphere to a semi-liquid phase sintering temperature to sinter the alloy powder.

Abstract: A titanium nitride base cermet with high toughness comprises, by weight, 42 to 95% of TiN, 2 to 20% of one or more of Mo, W and the carbides thereof, 2.85 to 30% of an Ni, Co or a mixture thereof, and 0.15 to 8.0% of Al.sub.4 C.sub.3, with the balance being inevitable impurities, wherein half or less of TiN may be replaced with one or more of the carbides and/or carbonitrides of metals from the Groups IVa and Va of the periodic table, with the proviso that the amount of TiN is no less than 30% in the cermet.

Abstract: A titanium carbide base cermet with a high toughness which consists essentially of, in weight percentage, a dispersed phase of from 70 to 95% free from chromium carbide, and a binder phase of from 5 to 30%;(1) said dispersed phase consisting essentially of:(i) titanium nitride: from 10 to 25%,(ii) at least one of tungsten, molybdenum and carbides thereof: from 10 to 30%,(iii) zirconium carbide: from 0.2 to 5.0%,(iv) aluminum nitride: from 0.1 to 5.0%, and(v) A composite carbide produced by substituting at least one of tantalum carbide and niobium carbide for from 3 to 50% of titanium carbide: balance: and,(2) said binder phase consisting essentially of at least one metal of iron group and incidental impurities.

Abstract: A wear-resistant hard metal free of tungsten carbide. The hard metal comprises: molybdenum carbide; a carbide of another transition metal; boron, boron nitride, boron carbide, or a mixture thereof, in an amount of 0.1 to 1% by weight boron, based on the weight of the molybdenum carbide, other transition metal carbide and boron-containing material, and a binder metal selected from the group consisting of metals of the iron group of the Periodic Table of Elements, and alloys thereof.

Abstract: New cobalt base alloys containing chromium and carbon are disclosed. The alloys are subjected to rapid solidification processing (RSP) technique which produces cooling rates between 10.sup.5 to 10.sup.7 .degree. C./sec. The as-quenched ribbon, powder etc. consists predominantly of amorphous phase. The amorphous phase is subjected to suitable heat treatments so as to produce a transformation to a microcrystalline alloy which includes carbides; this heat treated alloy exhibits superior mechanical properties for numerous industrial applications.

Abstract: Fully dense consolidated powder alloys of iron, cobalt and/or nickel characterized by having an ultrafine microstructure exhibiting a substantially uniformly dispersed harding phase of particle size essentially less than 3 microns, are produced from prealloyed powders by rapidly quenching an atomized molten alloy charge and subjecting the solidified alloy powder particles to the step of hot consolidation to produce substantially fully dense metal stock directly from prealloyed powder.

Abstract: A WC-Ni-Co-Al-Cr system hard alloy suitable as a material for hot working apparatus members has a lower Co content than conventionally used WC-Co system alloys and contains in place thereof greater quantities of Ni and Al, whereby, and also because the oxygen content is suppressed at a low level, fine particles of .gamma.' phase (Ni.sub.3 Al) are precipitated in a binder phase which binds the disperse phase of WC to impart characteristics such as excellent toughness, abrasion resistance, high-temperature strength, and oxidation resistance.

Abstract: Method for hard facing iron or iron base alloy substrates using as a hard facing material a solid composition consisting essentially of grains of vanadium carbide having in solid solution from about 10 to 50% by weight tungsten, and containing from about 0.5 to 5% by weight manganese and 0 to 3% by weight copper in the grain boundaries.

Abstract: Method for hard-facing substrates is disclosed using a hard facing material consisting essentially of at least one vanadium carbide. In a particular embodiment of the invention tungsten is present in the hard facing material in solid solution with vanadium carbide.

Abstract: An abrasion resistant ferro-based sintered alloy comprising 0.8 to 1.5% by weight of carbon, 0.5 to 2.5% by weight of chromium, 2.0 to 6.0% by weight of molybdenum, 1.5 to 5.0% by weight of nickel, 0.1 to 2.0% by weight of tungsten, 0.2 to 5.0% by weight of copper and the balance iron wherein said alloy contains molybdenum particles around which nickel is distributed and which are uniformly dispersed in the base structure comprising a mixture of pearlite, bainite and martensite and said alloy contains composite carbide of Fe-Cr-W-C dispersed in the base structure, is disclosed.

Abstract: An abrasion resistered sintered alloy for use in internal combustion engines which comprises 0.5 to 4.0% by weight of carbon, 1.5 to 16.0% by weight of Nb, 0.1 to 4.0% by weight of Mo, 0.1 to 1.0% by weight of Ni and 0.1 to 5.0% by weight of P which permits liquid-phase sintering at temperatures not higher than 1,250.degree. C., and have 0.2 to 10% by volume of sintering pores at least 40% of which consist of pores having a pore size of not larger than 150 .mu.m is disclosed.

Abstract: An abrasion resistant sintered alloy for use in internal combustion engines which comprises 0.5 to 4.0% by weight of C, 5.0 to 3.0% by weight of Cr, less than 10.0% by weight of at least one of Ni, Mo, Co and Cu, 0.1 to 5.0% by weight of at least one of P, B and Si which permits liquid-phase sintering at temperatures not higher than 1,250.degree. C. and the balance iron, and have hardness after sintering of Hv 500 to 1,200, 7 to 45% by area ratio of cementite or eutectic crystal of cementite and P and 0.2 to 10% by volume of sintering pores at least 40% of which consist of pores having a pore size of not larger than 150 .mu.m.

Abstract: A sintered compact for use in a machining tool comprising 80 to 10 volume % of a high pressure form of boron nitride, and the balance a matrix of at least one binder compound material selected from the group consisting of a carbide, nitride, carbonitride, boride or silicide of IVa and Va transition metal of the periodic table, their mixtures as well as the solid solution of these compounds; the matrix forming a continuous bonding structure in the sintered body.A method of producing the compact comprises preparing a mix of 80 to 10 volume % of a high pressure form of a boron nitride powder with 20 to 90 volume % of at least one powdered binder compound selected from the group consisting of a carbide, a nitride, a carbonitride, a boride and a silicide of a IVa, or a Va metal, mixtures thereof or solid solutions of these compounds, and sintering the mix under pressures more than 20 Kb at temperatures higher than 700.degree. C. for more than 3 minutes.

Abstract: A bearing material which is excellent in seizure resistance, wear resistance and conformability. The bearing material is prepared by sintering, on a backing steel sheet, a powder mixture consisting of Cu-Pb base alloy powder or its constituent metal powders and 1 to 30 wt. % of one or more members of hard material powders. The hard material powders mean the powders of Mo, Co, Fe.sub.3 P, Fe.sub.2 P, self-fusing alloys, FeB, Fe.sub.2 B, Fe-Cr, Fe-Mn, Fe-Si, Cr, W; SiC and other carbides, TiN and other nitrides, and SiO.sub.2 and other oxides. The bearing material of the present invention is characterized in that it has excellent sliding characteristics especially relative to the materials having rough surfaces.

Abstract: An improvement in a cemented hard metal is disclosed. A molybdenum-tungsten-carbonitride is disclosed having the structure of tungsten carbide wherein the molybdenum and/or tungsten are at least partly substituted for by a metal selected from the group consisting of Cr, Nb, Ta, V, Re and mixtures thereof. The carbonitride may be mixed with a binder metal and sintered in a conventional manner to form a dense, substantially pore-free material.

Abstract: A liquid phase sintered dense composite body comprising a hard refractory metal carbide which is densely cemented by sintering with a metal or alloy components. The sintered composite body incorporates at a surface or in the interior a multiplicity of metallic elements consisting of coarse grains, strands and/or plates of either the same metal or alloy as the cementing component or metallic elements having a melting point at least 120.degree. C. higher than the temperature at which the liquid phase takes place on sintering. This liquid phase sintered dense composite body is manufactured by placing the coarse grains, strands and/or plates on the surface or within the compacted powder mixture prior to the liquid phase sintering operation.

Abstract: A workpiece of alloy steel is produced by sintering under a nonoxidizing atmosphere a mass of malleable-iron powder admixed with a comminuted complex ferroalloy. The latter, obtained from a molten mixture of several simple high-carbon ferroalloys saturated with graphite, is a blend of at least three nonferrous metals and iron in carbide form, including a complex carbide of formula M.sub.7 C.sub.3 containing iron and manganese with the possible addition of chromium and another carbide of formula M'.sub.2 C/M'C containing molybdenum with the possible addition of vanadium and/or niobium. The carbidically bound carbon amounts to at least 4%, by weight, of the ferroalloy composition and may constitute between 10% and 60% of the carbon of the sinterable powder mixture to which elemental carbon may be added as graphite. As the mass of iron and ferroalloy particles compacted under high pressure is sintered at temperatures between about 1150.degree. and 1300.degree. C.

Abstract: A powder metallurgy tool steel article for use in applications requiring high wear resistance having a carbide content of 10 to 18 volume percent of substantially all MC-type vanadium carbides, which carbides are substantially spherical and uniformly dispersed; the carbon content of the article is balanced relative to the carbide formers vanadium, chromium and molybdenum to provide an amount of carbon in the matrix of the article sufficient to permit the article to be heat treated to a hardness of at least 56 R.sub.c.

Abstract: A sintered steel alloy, particularly for hot-working tools, of the type comprising a hard metal compound such as titanium carbide and a matrix alloy of nickel martensitic steel containing at least a small amount of titanium, is featured by a substantially higher than usual molybdenum content providing an improvement in toughness and hardness when appropriately heat treated.

Abstract: Hard-facing of iron and iron base alloy substrates is disclosed using a hard facing material in the form of granules consisting essentially of grains of chemically combined vanadium, tungsten, molybdenum, and carbon bonded by a binder metal of nickel-molybdenum alloy.

Abstract: A sintered compact for use in a cutting tool and a method of producing the same are disclosed. The compact comprises 95 to 20 volume % of diamond finer than one micron in size and the balance binder also finer than one micron selected from the group of WC, (MoW)C, WC base cemented carbide and (MoW)C base cemented carbide.The method comprises pulverizing a diamond powder by using cemented carbide balls and a pot having a cemented carbide lining, mixing the diamond powder with a powder abraded from the balls and pot to produce a powder mix finer than one micron containing 95 to 20 volume % of diamond, heat-treating the powder mix in vacuum so as to degas, and hot-pressing the powder mix under high pressure at high temperature within the stable range of diamond.

Abstract: Cobalt or cobalt alloy composite materials reinforced with continuous silicon carbide fibers, which have a high tensile strength, a low elongation, a high Young modulus and a high tensile strength at a high temperature, are produced by filling spaces in piles of the continuous silicon carbide fibers containing 0.01%-30% by weight of free carbon with melted or powdery metallic cobalt or cobalt alloy and integrating the said fibers with the said metal.

Abstract: The alloy of the invention is of the type wherein 30-70% by volume of hard components are homogeneously dispersed in a matrix of binder metal (Fe, Co or Ni). The hard components are carbides or carbonitrides and/or borides of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and/or W. The mean grain size of the hard component particles is between 0.01 and 1.0 micron and their grain size distribution, represented by the standard deviation S, in which S.sup.2 .ltoreq.(M/1+1.5 M.sup.z).sup.2 .mu.m.sup.2, not more than 15% of the grains are larger than 1.2 microns.