Abstract: An aluminum based metal matrix composite is produced from a charge containing a rapidly solidified aluminum alloy and particles of a reinforcing material present in an amount ranging from about 0.1 to 50 percent by volume of the charge. The charge is ball milled energetically to enfold metal matrix material around each of the particles while maintaining the charge in a pulverulant state. Upon completion of the ball milling step, the charge is consolidated to provide a powder compact having a formable, substantially void free mass. The compact is especially suited for use in aerospace, automotive, electronic, wear resistance critical components and the like.

Abstract: A sintered hard metal body having improved heat resistance and higher cutting performance is produced by a process including mixing together at least one hard substance, at least one binder material, and at least one of at least one complex carbide and at least one complex nitride to form a starting mixture each constituent of which is in powdered form. The at least one hard substance is selected from the group consisting of carbides, nitrides, and carbonitrides of transition metals of Groups IVB, VB and VIB of the Periodic Table of Elements, is present as at least one of a carbide, a mixed carbide, a nitride, a mixed nitride, a carbonitride, and a mixed carbonitride, and has a cubic crystal form. The at least one binder metal is selected from the group including iron, nickel and cobalt.

Abstract: A magnesium-based composite material having improved mechanical strength, and in particular an improved modulus of elasticity, and a relatively low density. The material is provided by pressing and sintering a mixture of magnesium or magnesium-based alloy particles or a particulate combination of magnesium particles and particles of one or more additional metals, with a reinforcement additive of boron, or boron-coated B.sub.4 C, Si.sub.3 N.sub.4, SiC, Al.sub.2 O.sub.3 or MgO particles.

Abstract: A combination of a first slide member made of ferrous material in which at least a slide surface layer thereof has a metallurgical structure having granular carbides dispersed in a matrix phase, and a second slide member made of ferrous material in which at least a slide surface layer thereof has a metallurgical structure having network-like carbides dispersed in a martensite matrix phase. A proportion of an area occupied by the granular carbides on the slide surface of the first slide member is larger than a proportion of an area occupied by the network-like carbides on the slide surface of the second slide member, and owing to this difference in these occupied area proportions, generation of coagulative wear (scuffing) between the respective slide members can be effectively prevented, and a good anti-wear property is obtainable from viewpoints of scuffing as well as pitting.

Abstract: A method of joining two porous bodies of silicon carbide is disclosed. It entails utilizing an aqueous slip of a similar silicon carbide as was used to form the porous bodies, including the sintering aids, and a binder to initially join the porous bodies together. Then the composite structure is subjected to cold isostatic pressing to form a joint having good handling strength. Then the composite structure is subjected to pressureless sintering to form the final strong bond. Optionally, after the sintering the structure is subjected to hot isostatic pressing to further improve the joint and densify the structure. The result is a composite structure in which the joint is almost indistinguishable from the silicon carbide pieces which it joins.

Abstract: An improved ceramic-metal composite comprising a mixture of a ceramic material with a ductile intermetallic alloy, preferably Ni.sub.3 Al.

Abstract: A coated cemented carbide alloy having jointly a high toughness and high wear resistance is produced by specifying the cooling rate during sintering in efficient manner, which alloy comprises a cemented carbide substrate consisting of a hard phase of at least one member selected from the group consisting of carbides, nitrides and carbonitrides of Group IVa, Va and VIa metals of Periodic Table and a binder phase consisting of at least one member selected from the iron group metals, and a monolayer or multilayer, provided thereon, consisting of at least one member selected from the group consisting of carbides, nitrides, oxides and borides of Group IVa, Va and VIa metals of Periodic Table, solid solutions thereof and aluminum oxide, in which the hardness of the cemented carbide substrate in the range of 2 to 5 .mu.m from the interface between the coating layer and substrate is 800 to 1300 kg/mm.sup.

Abstract: A process for the production of a secondary powder composition having a nanocrystalline structure and being comprised of binary or quasi-binary substances composed of at least one of the elements Y, Ti, Zr, Hf, Nb, Mo, Ta and W and at least one of the elements V, Cr, Mn, Fe, Co, Ni, Cu and Pd, optionally also containing further ingredients, such as Si, Ge, B and/or oxides, nitrides, borides, carbides, and their possible mixed crystals. The components are in powdered form and are mixed in elementary form or as pre-alloys and have particle sizes ranging from 2 to 250 .mu.m. The powder components are subjected to high mechanical forces in order to produce secondary powders having a nanocrystalline structure. The secondary powders obtained in this way can be processed into molded bodies according to known compression molding processes, but at a temperature below the recrystallization temperature.

Abstract: The present invention relates to a method of sintering ceramics and ceramics obtained by said method. According to the present invention, the synthesis and sintering of ceramics can be simultaneously carried out by utilizing the reaction heat generated when at least one metallic element selected from metallic elements of IIIb, IVa, Vb and VIb groups of the Periodic Table is combined with at least one nonmetallic element such as B, C, N and Si without heat or by preliminarily heating the ceramics at temperatures remarkably lower than the usual sintering temperature ceramics, thus-produced are superior in abrasion resistance and corrosion resistance.

Abstract: A cutting element of flat shape suitable for use as a drill tip comprises a central abrading blade containing more than 80% vol. CBN sandwiched between two lateral support layers. The lateral layers consist of a refractory metal or alloy selected from the group consisiting of tungsten, titanium and alloys thereof. The compact may particularly have a roof or pentagonal shape. An intermediate transition film may be located between the refractory metal or alloy and the CBN blade.

Abstract: Disclosed is a roller for use in a rotary compressor, which roller comprising a sintered body consisting essentially of 0.5-2.0% by weight of C, 1.0-5.0% by weight of Cu, 1.2-3.0% by weight of Mo and a balance of Fe and unavoidable impurities. In the sintered alloy, hard particles of Fe-Mo alloy are dispersed in one of pearlitic and tempering martensitic matrix, and sintered pores of the sintered body is sealed with tri-iron tetroxide. Resultant sintered body has high wear resistance and scuffing resistance capable of being used as an inverter type compressor.

Abstract: A tough cermet made from 20-92 weight % of TiC and/or TiCN, 5-50 weight % of WC and 3-30 weight % of an iron-gorup metal. This tough cermet has a three phase grain microstructure and is made is mixing titanium carbonitride powder and up to 70 weight % of the total amount of the tungsten carbide fine powder. The resulting mixture is melted to form a solid solution, pulverized, mixed with the remaining amount of tungsten carbide fine powder, and sintered at temperatures of 1325.degree.-1650.degree. C.

Abstract: A method for manufacture of Group IVB metal carbide ceramic composites is provided wherein a permeable mass of filler and carbon is contacted with a molten Group IVB metal. The molten metal is maintained in contact with the permeable mass for a sufficient period to infiltrate the permeable mass and to react the molten metal with the carbon source to form a Group IVB metal carbide composite. The permeable mass may comprise a Group IVB metal carbide, or other inert filler, or a combination of filler materials.

Abstract: A method is disclosed for producing metal carbide grade powders, which comprises dry milling metal carbide powder which can be tungsten carbide, titanium carbide, tantalum carbide, niobium carbide, vanadium carbide, chromium carbide, and combinations thereof to increase the surface area of the powder particles to result in essetially all of the powders being converted to single crystals, forming a mixture of the resulting dry milled carbide powder, a binder metal which can be cobalt, nickel, and combinations thereof, and a wax, while heating the carbide powder, the binder metal and the wax to a temperature above the melting point of the wax and maintaining the temperature to result in a uniform distribution of the wax on the carbide and binder metal particles, forming a slurry of the mixture and water, attritor milling the slurry at a temperature below the melting point of the wax, and removing the water from the resulting attritor milled mixture and aggiomerating the mixture to produce the metal carbide grad

Abstract: A method for manufacturing a metal boride ceramic material, includes mixing metal boride powder with 1-20 wt. % metal powder and 0.1-10 wt. % carbon powder, shaping the mixture and firing it. Alternatively, the metal boride powder may be mixed with 0.1-89 wt. % metal carbide powder thereby make a mixture, followed by shaping the mixture and firing it.

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 powder metallurgy produced high speed tool steel article comprising a mixture of prealloyed high speed tool steel particles coated with a hard, wear resistant material, such as a carbide or nitride, mixed with prealloyed high speed tool steel uncoated particles; the particles are compacted to essentially full density and the hard, wear resistant material is at the boundaries of the coated particles and contained in a continuous matrix of the high speed tool steel. The article is produced by hot compacting a particle charge to essentially full density of a mixture of the coated and uncoated particles.

Abstract: A process is described for making a composite article without shrinkage, particularly of ceramic and metal wherein the article includes complex internal surfaces or cavities. The process requires forming an insert body that includes an external surface that corresponds to an internal cavity of the article. The insert body consists of a material having a melting temperature less than that of the article. The process further requires forming a porous compact about the insert body wherein the compact is formed into the substantially the net shape of the article. The compact is made of a material that is wetted by liquid insert material and has a sintering temperature greater than the wetting temperature of the insert material. The process further requires heating the article to a temperature such that the inserts substantially melts and infiltrates the porous compact forming the finished composite article.

Abstract: Compositions for the production of rare earth-ferromagnetic-metal permanent magnets comprise mixtures of rare earth-ferromagnetic metal alloy powder and a lesser amount of a powdered second-phase sintering aid, wherein there is added up to about 2 percent by weight of a particulate refractory oxide, carbide, or nitride additive. Permanent magnets are prepared by mixing the components, aligning the mixture in a magnetic field, pressing and sintering. The refractory material inhibits grain growth in the second phase during sintering, improving the magnetic properties of the major phase.

Abstract: Amorphous metal-ceramic and microcrystalline metal-ceramic composites are synthesized by solid state reaction-formation methods. These metal-ceramic composites are characterized by a composition that ranges from about 75 to about 99.9 percent ceramic in about 0.1 to about 25 percent amorphous or microcrystalline metal binder phase.

Abstract: An aluminum matrix composite containing evenly dispersed reinforcement particles in the aluminum matrix wherein the contents of oxygen and carbon are controlled so that their volume percentage is not larger than 20% and wherein the contents of the reinforcement particles, oxygen and carbon are controlled so that their volume percentage is not larger than 40%. The control of oxygen and carbon is effected by carrying out the main process at a non-oxidizing atmosphere and minimizing the addition of an anti-seizure agent required to facilitate the mechanical alloying treatment.

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 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: A method for synthesizing low density cermets of boron carbide and a metal binder, using decomposition of a metallic compound at controlled temperature and pressure.

Abstract: A powder metallurgy consolidation process and apparatus for carrying out said process produces integral metal bodies by heating metal powder of a predetermined composition to a temperature sufficient to cause solid state interparticle bonding, while simultaneously maintaining a reactive fluid in contact with the metal powder. The metal powder is compacted to a density greater than 90% of the full theoretical density of the composition after the reactive fluid has been removed. The reactive fluid is selected to modify the powder particle surface chemistry in order to improve bondability and to obtain other properties as desired. Metal bodies which have been consolidated by the process are sufficiently dense to be mechanically hot worked and exhibit exceptionally low retained gas content.

Abstract: A three step process in which a metal alloy selected from a tungsten based alloy and molybdenum based alloys is provided to prevent the decarbonization of the alloys. The process involves a three step sintering process wherein the atmosphere during the initial heating step is a mixture of carbon monoxide and hydrogen, thereafter at a intermediate temperature range the atmosphere is hydrogen and a final heating step at a elevated temperature is employed and the atmosphere is a mixture of inert gas and a source of carbon.

Abstract: A process for the production by power metallurgy of a material based on an aluminum alloy, a solid lubricant and at least one ceramic is disclosed. The process is characterized by using a ceramic in powder form with a granulometry of between 1 and 10 .mu.m.This invention finds application in the manufacture of components which are subjected to friction, in particular under hot condition, such as engine liners. These components provide an optimum compromise coefficient of friction and resistance to seizure and wear.

Abstract: A diamond sintered body for tools contains a diamond content in excess of 93 percent and not more than 99 percent by volume and a residue including at least one of a metal or a carbide selected from groups IVa, Va and VIa of the periodic table and an iron group metal of 0.1 to 3 percent by volume in total and pores at least 0.5 percent and not more than 7 percent by volume.

Abstract: A cubic boron nitride-based very high pressure-sintered material very excellent in both toughness and wear resistance and adapted to be employed in cutting tools for milling hard steels and like machining purposes. The very high pressure-sintered material consists essentially of: 1-20 percent at least one compound selected from the group consisting of titanium carbide and titanium carbo-nitride; 1-20 percent at least one compound selected from the group consisting of CoAl, NiAl, and (Co, Ni)Al; and 75-97 percent cubic boron nitride and inevitable impurities. The very high pressure-sintered material may further contain 1-10 percent at least one metal selected from the group consisting of cobalt and nickel.

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: A process for the production of valve seat rings by powder metallurgy wherein molybdenum disulfide in the range of about 0.5% to 1.5% by weight is added to a powder mixture containing 0.8% to 1.5% by weight graphite, 1.0% to 4% by weight lead, 0.5% to 5% by weight nickel, 1.2% to 1.8% by weight molybdenum, 9.6% to 14.4% by weight cobalt, and the remainder iron. The resulting powder mixture is pressed into valve seat rings at a pressing force between 40 and 60 and preferably 50 KN/cm.sup.2. The rings are then sintered in a neutral atmosphere at a temperature of 1100.degree. C. to 1200.degree. C., finally compressed at a pressing force above 120 KN/cm.sup.2 and heat-treated if required. The resulting valve seat rings have greatly improved wear properties when used in internal combustion engines using lead-free gasoline.

Abstract: Disclosed is a method for preparing a sintered body containing cubic boron nitride which comprise the steps ofcontacting a starting material containing boron nitride and/or a starting material containing at least one selected from the group consisting of metals of groups IVa, Va and VIa of the periodic table, silicon, aluminum, iron group metals and compounds of the aforesaid metals with at least one selected from the group consisting of borazine, a borazine derivative and a compound composed of boron, nitrogen and hydrogen as will release hydrogen by a thermal decomposition under pressure to form boron nitride; andsintering the material under conditions of a predetermined pressure and temperature under which cubic boron nitride is kept stable. Also disclosed is a method for preparing cubic boron nitride which comprises, in addition to the above steps, recovering cubic boron nitride from the obtained sintered body by a chemical and/or physical manner.

Abstract: A super heatresistant cermet and process of producing the same. A mixture, which contains about 10 to about 65% by weight of a powder of the carbonitride having titanium and tungsten, about 0.5 to about 10.0% by weight of a magnesium oxide powder and a tungsten powder, is pressed to form a compact, which is thereafter sintered in a vacuum or in an atmosphere of a nitrogen gas or an inert gas within the temperature range of about 1800.degree. to 2700.degree. C. to thereby decarburize the carbonitride with the magnesium oxide evaporated during the sintering, whereby there is produced a super heatresistant cermet containing about 10 to about 65% by weight of a carbonitride containing titanium and tungsten, about 0.01 to about 1.0% by weight of magnesium oxide, and tungsten as a binder. The super heatresistant cermet is excellent in impact resistance, wear resistance and plastic deformation resistance, and suitable for cutting tools.

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 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 process for producing composite materials which comprises subjecting particles of a malleable matrix material, i.e., a metal or alloy or the components of a matrix alloy and particles of a reinforcing material such as a carbide or an oxide or an intermetallic to energetic mechanical milling under circumstances to insure the pulverulent nature of the mill charge so as to enfold matrix material around each of said reinforcing particles to provide a bond between the matrix material and the surface of the reinforcing particle. The process is exemplified by the use of aluminum alloy as the matrix material and silicon carbide as the reinforcing particles. Reinforcing particles are present in an amount of about 0.2 to about 30 volume percent of total matrix and reinforcing particles. The invention is also directed to the product of the process.

Abstract: A powder metallurgy composite material comprising grains of a relatively hard material and a binder for binding the grains together, the binder being metastable and transformable at ambient temperature by the application of mechanical force from an initial state in which the major phase of the binder is austentic to a second state in which the major phase of the binder is martensitic, whereby the binder, while undergoing this transformation, absorbs mechanical energy applied to the composite material for increasing its fracture toughness and resistance to fatigue crack nucleation and propagation. Also disclosed is a method of heat-treating the composite materials to improve their transformation-toughening characteristics. A heat-treatable composite material having such improved transformation-toughening properties is also disclosed.

Abstract: Process for the preparation of a composite material incorporating an inorganic matrix in which are distributed inclusions of carbon-containing material, where it comprises the following stages:(a) mixing an inorganic powder with a liquid or viscous resin, which can be transformed into vitreous carbon by heat treatment,(b) subjecting the mixture of resin and inorganic powder to a first heat treatment performed under conditions such that the resin is hardened by crosslinking or polycondensation, and(c) subjecting the thus obtained hardened product to a second heat treatment for transforming the resin into vitreous carbon and thus forming said vitreous carbon inclusions.The composite material obtained comprises a copper matrix in which are uniformly and homogeneously dispersed vitreous carbon inclusions, the vitreous carbon content being at the most 8% by weight.The material is used in the production of electric contacts.

Abstract: A process improvement is disclosed for making diamond wire die compacts of the type which are generally described as an inner polycrystalline diamond mass surrounded by and bonded to a mass of metal bonded carbide, such as cobalt cemented tungsten carbide. It is known to make these dies by high pressure-high temperature processes, typical conditions being 50 kbar and temperatures in excess of 1300.degree. C. The improvement comprises disposing within the reaction sub-assembly (e.g. metal carbide and diamond within a zirconium cup) a set of discs of specific materials in specified arrangements. For example, on one side of the mass of metal carbide and diamond is disposed one disc of a diamond catalyst/solvent and one disc of a refractory metal such as molybdenum, and on the other side are disposed at least two discs of one or more transition metals such as zirconium. These discs are generally placed inside the sub-assembly cup.

Abstract: A fiber-reinforced metal composite material comprising a reinforcing material and a matrix, said reinforcing material being inorganic fibers containing at least two components selected from carbon (as a simple substance), metal oxides, metal carbides, metal nitrides and metal borides, and said matrix being metal alloys containing zinc and aluminum, or zinc and magnesium as main component.

Abstract: An improved diamond compact of the present invention comprises 20 to 85% by volume of diamond grains with a grain size of at least 3 .mu.m and the balance of a binder consisting of 20 to 95% by volume of ultra-fine diamond grains with a grain size of at most 1 .mu.m, at least one member with a grain size of at most 1 .mu.m, selected from the group consisting of carbides, carbonitrides, nitrides, borides of Group 4a, 5a and 6a elements of Periodic Table, solid solutions thereof and mixed crystals thereof and at least one member selected from the group consisting of iron group metals.

Abstract: In a process for producing a carbide grade powder mixture for making a cemented metal carbide, a mixture of metal carbide particles and wax is formed at a temperature above the melting point of the wax. The wax includes less than about 2 percent by weight of a wetting agent for reducing the surface tension of the wax when in water. The blended mixture including metal binder particles is milled with a liquid milling medium comprising water to substantially uniformly disperse the metal binder particles and to produce a slurry. The slurry is dried to remove the milling medium and produce a powder comprising particles of metal carbide, metal binder and wax.

Abstract: Metal-ceramic composites may be prepared by treating the ceramic component of the composite with a second metal prior to subjecting the metal-ceramic composite to a sintering operation. By pretreating the ceramic component of the composite, it is possible to obtain a composite which will undergo sintering at an elevated temperature to form a composite which will possess desirable characteristics such as increased density, hardness and low thermal coefficient of expansion, thus enabling the composites to be utilized in a wide variety of applications.

Abstract: Sintered silicon carbide materials are described, which have a metallized surface consisting essentially of a composition comprising 10 to 90% by weight of Si, balance a mixture of at least two components selected from Fe, Ni and Co.A process for producing the silicon carbide sintered materials having the metallized surface is also described.

Abstract: A method for producing a machinable, high strength hot formed powdered ferrous base metal alloy is provided which comprises providing a particulate mixture consisting of, in weight percent, from about 1.0 to about 3.0 percent copper, from about 0.16 to about 0.35 percent sulfur, from about 0.4 to about 0.8 percent carbon, with the balance being iron plus from 0 to about 2 percent incidental impurities; forming this particulate mixture into a preformed article having a predetermined configuration; sintering the so-formed article at a temperature sufficient to produce the desired alloy; and subjecting the sintered article to a hot forming treatment to produce a hot formed, machinable, high strength ferrous base powdered metal alloy article having a density near theoretical.

Abstract: A blade member for cutting tools comprises a cermet substrate having on a surface thereof a reaction layer. The reaction layer is composed of carbo-nitride of at least two metals in groups IV.sub.A, V.sub.A and VI.sub.A, the metals including Ti. The reaction layer may be composed of oxy-carbo-nitride of the above metals. The reaction layer may consist of inner and outer layers, the inner layer being composed of carbo-nitride of the above metals while the outer layer is composed of oxy-carbo-nitride of the above metals. The blade members with the reaction layer exhibits excellent toughness, wear resistance and thermoplastic deformation resistance. There is also disclosed a process for producing the above blade member.

Abstract: Mixed crystals of zirconium and hafnium carbides, possibly including the carbonitrides, are used in place of tantalum carbide in sintered hard metals. The new products contain one or more hard metals of Groups IV to VI of the Periodic Table of the Elements other than the mixed crystals, in particular, titanium and tungsten carbides, possibly with carbides of vanadium, niobium, molybdenum or chromium, and one or more iron group metals or alloys, preferably cobalt, is or are used as a binder. The sintered hard metals are made essentially by a 2-stage process, mixed crystal material comprising zirconium and hafnium carbides being formed in the first stage and being combined with the binder in the second stage, the one or more other hard metals of Groups IV to VI being incorporated in one or both stages. Any tendency to microporosity, shown particularly by products having a nitrogen content, is avoided by hot isostatic pressing.

Abstract: The invention enables to obtain a compound sintered compact for use in a cutting tool having particularly high properties in respect of bonded strength, hardness, wear resistance, plastic deformability and rigidity by bonding a diamond or cubic boron nitride containing hard layer to a cemented carbide substrate with interposition of an intermediate bonding layer.