Abstract: This invention relates to a diamond compact for a wire drawing die, which comprises 70 to 95% by volume of diamond powder with a particle size of at most 50 microns and the balance of a binder phase consisting of a carbide of WC or (Mo, W)C with a particle size of at most 1 micron and an iron group metal, the carbide and iron group metal in the binder phase being in such a proportion by weight that the content of the carbide is more than that corresponding to the eutectic composition.

Abstract: An improved sintered compact for use in a cutting tool is proposed which comprises 80 to 95 volume % of high pressure form boron nitride, a binder material which is a carbide, a nitride and/or a carbonitride of a IVb and Vb transition metal in the periodic table, and aluminum compounds. It may further include copper and/or iron group metal or metals. The sintered compact obtained has high hardness even though the sintering pressure and temperature are relatively low.

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 process of producing a sintered compact comprises filling a cup with a powdered material to be sintered, putting on an opening of the cup a covering member consisting of a lid and solder so as to permit ventilation between the interior and exterior of the cup to form a cup assembly, applying heat as well as vacuum to the cup assembly to degas the powdered material, melting the solder by the continuation of heat to air-tightly seal the cup with the lid to obtain a closed cup compressible under high pressure at high temperature while maintaining the air-tight seal, and hot-pressing the closed cup to obtain a sintered compact.The covering member may include a porous lid closing the cup and a solder put on the porous lid.

Abstract: The invention relates to a diamond sintered compact wherein diamond crystal particles are uniformly oriented in a particular direction and the method for producing the same, and has for an object to provide a diamond sintered compact having a high thermal conductivity particularly suitable for heat sink for use in the field of electronics.According to the invention, graphite is used as carbonaceous raw material, diamond crystal particles having such elongated shape that the ratio of the length of the long axis to that of the short axis is more than 2 being synthesized in such state that the greater part of the crystal particles have their long axes uniformly oriented in a particular direction, the crystal particles being sintered in the direction of the long axes thereof so that transformation of the graphite into diamond and sintering thereof may be accomplished synchronously.

Abstract: The invention relates to a diamond sintered body having a high wear resistance and making it possible to obtain a processed surface of high dimensional precision and beautiful finish as a wear resisting tool blank for use particularly in a wire drawing die, shaving die and the like, as a tool blank for use in a cutting tool for a workpiece consisting of nonferrous metals, plastics, ceramic, etc., and as a cutting tool blank for use in a glass cutter, synthetic building material cutting blade, etc., and method for producing the same, wherein a mixture comprising a diamond powder below 1.mu. and a powder below 1.mu.

Abstract: The invention relates to a sintered body for use in a cutting tool comprising a cutting edge forming part having particularly high hardness and wear resistance bonded to a supporting member having high plastic deformability, stiffness, transverse rupture strength, thermal conductivity, thermal expansion coefficient, resistance to corrosion, oxidization and the like, and to a method for producing the same. A diamond powder or high pressure form boron nitride powder is placed in contact with preliminarily sintered cermet constituted by carbide crystals chiefly comprising molybdenum in the form of (Mo, W)C bonded by iron group metals, the combined body being sintered at a temperature and pressure under which the diamond powder or high pressure form boron nitride powder is thermodynamically stable so that the sintered body of the diamond or high pressure form boron nitride is bonded to the cermet thereby enabling to obtain a sintered body having the said high properties for use in a cutting tool.

Abstract: This invention relates to a hard alloy comprising 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 as a predominant component, and a binder phase consisting of at least one element selected from the group consisting of iron, cobalt, nickel and chromium, in which a hard phase consisting of a compound of M.sub.2 C type having a crystal structure of hexagonal type is evenly dispersed.

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: This invention relates to a process for producing sintered hard metals which comprises sintering a compact for the sintered hard metals or sintering a formed body obtained from the compact through a presintering treatment and, if necessary, a machining treatment, a part or all of the heating steps and cooling steps being carried out in an atmospheres of hydrogen and an atmosphere of carbon monoxide.

Abstract: The present invention relates to a process for the production of an alloy powder (Mo, W) for powder metallurgy, which comprises chemically or mechanically mixing molybdenum and tungsten in the form of compounds and reducing the mixed powder with hydrogen, and a process for the production of a hard solid solution (Mo, W)C from the alloy powder (Mo, W), which comprises carburizing the alloy powder (Mo, W).

Abstract: This invention relates to a process for the production of a solid solution of compounds consisting of, in combination, at least 10 mol %, based on all metallic components, of molybdenum, at least one metallic element selected from the Group IVa, Va and VIa elements of the Periodic Table and at least one of non-metallic elements, which comprises mixing the metallic elements in the form of compounds or solutions thereof, adding carbon, optionally with at least one of non-metallic elements to the mixture, subjecting the resulting mixture to a reducing reaction with carbon and then subjecting to a solid solution-forming treatment in a reducing, carburizing or nitriding atmosphere.

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: This invention relates to surface-coated cemented carbide articles having a monolayer or multilayer consisting of one or more materials selected from oxides, carbides, nitrides and mixtures or compounds thereof, the most interior layer, in contact with the surface of the cemented carbide substrate, consisting of one or more materials selected from carbides and carbonitrides of Group IVa, Va and VIa elements, wherein the thickness of a decarburized layer (.eta. phase) present between the cemented carbide substrate and most interior coating layer is 0.5 micron or less in a case where the curvature of the interface is zero and the lattice constant of the binder metal of the coated cemented carbide article, as a mean value from the interface to 50 microns, is not more than that of the iron group metal solid solution by 0.005 A or more.

Abstract: The present invention relates to a hard cemented carbonitride alloy for cutting tools, which comprises 97 to 75% by weight of a hard phase and 3 to 25% by weight of a binder metal, the hard phase consisting of metallic components of titanium as a main component, 5 to 40% by weight of one or more of tungsten and molybdenum and 3 to 40% by weight of tantalum and non-metallic components of carbon and nitrogen, the proportion of nitrogen being 5 to 40% by weight of the non-metallic components and the binder metal being at least one element selected from the group consisting of iron, cobalt and nickel.

Abstract: This invention relates to a cemented carbonitride alloy in which the hard phase consists of[(Group IVa metal).sub.A (Group Va metal).sub.B (Group VIa metal).sub.C ]-(C.sub.X N.sub.Y).sub.Zwherein A, B, C, X and Y are respectively mole fractions, Z is a mole ratio of the metalloid components to the metal components and there are among A, B, C, X, Y and Z the relations ofA + B + C = 1, X + Y = 1,4a + 5b + 6c + 4xz + 5yz .gtoreq. 8.6,0.05 .ltoreq. y .ltoreq. 0.50 and 0.85 .ltoreq. Z .ltoreq. 1.0.the hard phase is combined by at least one binder metal from the iron group and there are in the alloy structure WC phase and the hard phase having the crystal structure B1 and containing Ti in a proportion of at least 20 atomic percent to the metallic atoms.

Abstract: A process for the production of tungsten carbide or mixed metal carbides, which comprises mixing tungsten oxide powder of mixed high melting point metal oxide powders with carbon powder in an amount sufficient to form the corresponding carbide, heating the mixture at a temperature of higher than 1000.degree. C in an inert atmosphere or in vacuum to reduce the oxygen content and then heating at a temperature of higher than 1400.degree. C in hydrogen atmosphere, thereby to form tungsten carbide or mixed metal carbides directly from the corresponding oxide.

Abstract: Surface-coated cemented carbide articles, in particular, cutting tools very excellent in wear resistance and heat resistance are made by an improved method according to the invention. This improved method comprises providing a 3-50 % by weight dispersion of fine powders of 20 microns or less containing 50 % or more of titanium carbide in a liquid consisting mainly of an organic solvent, applying a DC voltage of 10-500 volts to the surface of tungsten carbide base cemented carbides containing 4-30 % of a binder metal in said dispersion to thus cause electrophoretic deposition of the fine powders thereon, heating the coated surface at a temperature of 1260-1550 .degree.C in vacuum or in a reducing or inert atmosphere and thereby forming a coating layer consisting mainly of titanium carbide of 100 microns or less on the surface of the cemented carbides.