摘要:
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).
摘要:
A ceramics composite material containing crystallized glass as the matrix and fibers or whiskers of ceramics as a reinforcement material, is obtained by melting original glass to form crystallized glass, compounding the same with fibers or whiskers of oxide ceramics and thereafter crystallizing the original glass. This ceramics composite material does not form any voids and can easily contain at least 50 volume percent of the reinforcement material, whereby a good mechanical strength and fracture toughness are achieved. In the compounding step, the content of the reinforcement can be further increased by forcing out any excess part of the original glass from the reinforcement material by applying pressure to a substance obtained by mixing the original glass with the reinforcement. Further, the ceramics composite material can be efficiently formed into a desired configuration by heating because the original glass flows viscously.
摘要:
A ceramics composite material containing crystallized glass as the matrix and fibers or whiskers of ceramics as a reinforcement material, is obtained by melting original glass to form crystallized glass, compounding the same with fibers or whiskers of oxide ceramics and thereafter crystallizing the original glass. This ceramics composite material does not form any voids and can easily contain at least 50 volume percent of the reinforcement material, whereby a good mechanical strength and fracture toughness are achieved. In the compounding step, the content of the reinforcement can be further increased by forcing out any excess part of the original glass from the reinforcement material by applying pressure to a substance obtained by mixing the original glass with the reinforcement. Further, the ceramics composite material can be efficiently formed into a desired configuration by heating because the original glass flows viscously.
摘要:
An SiC whisker-reinforced Si.sub.3 N.sub.4 composite material comprising a sintered body of an Si.sub.3 N.sub.4 matrix having dispersed therein SiC whiskers, wherein said SiC whiskers are uniaxially orientated; a process for producing an SiC whisker-reinforced Si.sub.3 N.sub.4 composite material which comprises mixing (1) SiC whiskers having a coating comprising an oxide of at least one metallic element selected from the group consisting of Be, Mg, Ca, Sr, and Ba of the group 2A; Sc, Y, and La of the group 3A; Ti, Zr, and Hf of the group 4A; and Li, Al, and Si with (2) Si.sub.3 N.sub.4 powder, and sintering the mixture; and a process for forming said metal oxide coating on the surface of whiskers which comprises dipping whiskers in a solution of an inorganic or organic salt of at least one metallic element selected from the group consisting of the elements of the groups 2A, 3A, and 4A of the periodic table, Li, and Al and heat treating the whiskers having adhered thereto the metallic salt at a temperature not less than the thermal decomposition temperature of said metallic salt. The SiC whisker-reinforced Si.sub. 3 N.sub.4 composite material exhibits improved strength particularly at high temperatures and improved toughness.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.