Abstract: A member for a semiconductor structure is constructed, for example, as a mounting, or as a cover, or as a heat sink. Such a component is obtained by joining an aluminum nitride insulating substrate and a radiating element. The metal material for forming the radiating member has a thermal conductivity of at least 120 W/mK and a thermal expansion coefficient within a range of 4 to 6.0.times.10.sup.-6 /K.sup.-1. Preferably the material forming the radiating element is made of a tungsten alloy containing copper by not more than 5 percent by weight.

Abstract: A member for a semiconductor apparatus for carrying or holding a semiconductor device, obtained by joining an aluminum nitride substrate and a radiating substrate, comprises an insulating member formed by an aluminum nitride sintered body to be provided thereon with the semiconductor device, a radiating member to be joined to the insulating member, which radiating member is mainly formed of a copper-tungsten alloy or a copper-molybdenum alloy, a stress relieving member interposed between the insulating member and the radiating member and a silver solder member for joining the insulating member, the stress relieving member and the radiating member with each other.

Abstract: A silicon nitride sintered material for cutting tools comprising from about 3 to 10 wt % of partially stablized zirconium oxide, from about 1 to 5 wt % of aluminum oxide, and from about 1 to 10 wt % of yttrium oxide, the balance being silicon nitride, and the process for making the same.

Abstract: Disclosed is a process for preparation of a sintered silicon nitride. The process comprises the steps of:mixing a powder of silicon nitride with a powder of a sintering agent;compacting the obtained mixture; andsintering the compacted mixture in a non-oxidizing atmosphere.The feature of the process is that the powder of the sintering agent includes a powder mixture of oxide and/or hydroxide of at least two kinds of metals which has been prepared by co-precipitation.Due to the use of the co-precipitated powder as the sintering agent, it is possible to obtain a sintered silicon nitride having an excellent strength and uniformity in quality. The obtained sintered silicon nitride is preferably used as an engineering ceramic.

Abstract: Composite sintered Si.sub.3 N.sub.4 material particularly suitable as a cutting tool material for cutting cast iron is composed of:a sintered Si.sub.3 N.sub.4 substrate containing 0.1 to 10 weight % of Y.sub.2 O.sub.3, 0.1 to 10 weight % of ZrO.sub.2 and if necessary 1 to 15 weight % of at least one member selected from the group consisting of compound and solid solution thereof of elements of IVa (except Zr), Va and VIa of the Periodic Table and the balance being of Si.sub.3 N.sub.4 ;a first layer of Ti compound coated on the sintered Si.sub.3 N.sub.4 substrate;a second layer of Al.sub.2 O.sub.3 coated on the first layer; and the total thickness of the first and second layers being in the range of 1 to 20 microns.The above composite sintered Si.sub.3 N.sub.4 material has an improved abrasive resistance particularly in the case of cutting cast iron at high speed, while retaining the excellent physical properties of Si.sub.3 N.sub.4. Such a composite sintered Si.sub.3 N.sub.

Abstract: A composite compact component made of a composite compact consisting of a diamond or BN powder bonded to a hard sintered alloy base during a sintering operation, and a substrate composed of steel or a hard sintered alloy bonded to the base of the composite compact through a high strength filler metal or alloy having a melting point of at least the liquidus point of the hard sintered alloy base. A process of making set composite compact component is also disclosed as well as a drill bit containing said composite compact component and variations thereof.

Abstract: An electrically-conductive sintered compact of silicon nitride which is machinable by electrical discharge machining and a process to produce the same. TiN and/or TiC powder is added to a powder of silicon nitride in an amount 15-40% by volume to act as a conductivity-supplying agent while 0.01-3.0% by volume MgO and/or Al.sub.2 O.sub.3 powder is added as a sintering assistant. The mixed powders are then preformed in a desired shape and sintered in a nonoxidizing environment at 1,600.degree. C.-2,000.degree. C. to obtain a compact of silicon-nitride machinable by electrical discharge machining due to its electrical conductivity being at least 1 S.multidot.cm.sup.-1.

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 tool for warm and hot forgings is proposed which is made by bonding cemented carbide to steel by applying electron beams or laser to the joint. The cemented carbide includes a hard phase of tungsten carbide and a binder metal phase containing at least one of Ni, Co and Fe, and at least one of Cr, Mo and W, the latter forming a solid solution. A process for manufacturing such a tool is also proposed in which unfocussed high-energy beams are applied to each side of the joint and focussed beams are then applied to a point slightly away from the joint toward the cemented carbide.

Abstract: Process for the production of bonded hard alloys, which comprises inserting a thin sheet of a Fe group metal or its alloy as a filler in between the surfaces of at least one kind of hard alloy, and applying a high energy beam to a part or all of the thin sheet to melt and solidify the thin sheet in a slit form, thereby bonding the hard alloys together.

Abstract: The present invention relates to a process for the production of a solid solution constructed of at least one hard phase having a crystal structure of simple hexagonal type and selected from mixed carbides or carbonitrides of molybdenum and tungsten, which process comprises preparing an alloy powder consisting of a solid solution of molybdenum and tungsten, adding to the alloy powder carbon in an amount necessary for forming (Mo, W).sub.2 C and/or (Mo, W).sub.2 (CN), heating the mixture at a temperature at which (Mo, W).sub.2 C and/or (Mo, W).sub.2 (CN) is stable, adding to the (Mo, W).sub.2 C and/or (Mo, W).sub.2 (CN) carbon in an amount necessary for forming (Mo, W)C and/or (Mo, W)(CN) optionally with an iron group metal and then heating the mixture at a temperature at which (Mo, W)C and/or (Mo, W)(CN) is stable.

Abstract: The invention relates to a sintered hard metal having a high wear resistance and heat resistance as material for cutting tools and wear resistant tools and the method for producing the same. The sintered hard metal has a hard phase comprising a phase having a B-1 type crystal structure containing more than one kind of IVa, Va and VIa group metals in the Periodic Table and also the elements, carbon, nitrogen and oxygen and a WC phase, the hard phase and a bonding phase chiefly consisting of a ferrous metal which is sintered by a powder metallurgy technique, whereas the oxygen in particular is added thereto making it possible to obtain a sintered hard metal having said excellent properties.

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: 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: 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: 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: 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.