Abstract: Silicon oxynitride sintered body is obtained by sintering a base starting material mixture comprising silicon oxynitride componentand a solution of at least one alkoxide selected from alkoxides of at least one element selected from the group consisting of Al, Sc, Y and rare-earth elements.Fiber-reinforced ceramic sintered body is obtained by sintering the base starting material mixture further inclusing 5-40% by weight of SiC whiskers and/or .beta.-Si.sub.3 N.sub.4 whiskers, wherein alkoxide component is 0.5-30% by weight as oxides.The alkoxide component is deposited on the other material powders and calcined to provide well dispersed oxide layer on the powder surface which forms uniform matrix phase giving high density by sintering. Sintered bodies (with or without whiskers) have low deterioration at high temperatures.

Abstract: The present invention is directed to a method of producing a sintered hard metal having a diamond film wherein a gas that is obtained by activating a raw material gas containing 2 to 60 mol % of carbon monoxide and hydrogen gas is brought in contact with a sintered hard metal to form a diamond film, thereby a diamond film can be formed on said sintered hard metal with the adhesion of the diamond excellent.

Abstract: A zirconia-base sintered body comprising a sintered substrate containing 30% by volume or more of tetragonal zirconia and a coating film disposed thereon, characterized in that the diffusion coefficient of oxygen in a material forming said coating film at no higher than 550.degree. C. is smaller than that of oxygen in said tetragonal zirconia at a temperature of no higher than said temperature.

Abstract: Whisker-reinforced ceramics with high fracture toughness and strength consists essentially of 5-40 weight % SiC including SiC whiskers, 1-30 weight % of at least one kind of oxides of elements selected from the group consisting of Al, Sc, Y and rare-earth elements, and the balance being silicon oxynitride constituents, wherein said SiC whiskers are present in an amount of no less than 5 weight % of the total essential constituents.The silicon oxynitride constituents are Si.sub.2 N.sub.2 O or a mixture of silicon nitride and silica (0.83-1.22 by molar ratio), or a mixture of Si.sub.2 N.sub.2 O and said mixture of silicon nitride and silica. Silicon oxynitride and SiC phases are predominant.

Abstract: A surface structure of A1N substrate comprising:an A1N substrate,an intermediate layer disposed on the A1N substrate, anda metallized layer disposed on said intermediate layer, said intermediate layer comprising at least aluminum, nitrogen and oxygen. The metallized layer has a main component of one of Mo-Mn alloy, Mo and W, and has a thickness of 1-20 .mu.m,This surface structure is produced by coating a surface of A1N substrate with metallizing layer components, heat treating the resultant coated substrate at a temperature of 200.degree.-500.degree. C. under an oxidizing atmosphere, and further heating the heat treated coated substrate at a temperature of 1200.degree.-1400.degree. C. under a nonoxidizing atmosphere having a dew point of -35.degree.to 5.degree. C.

Abstract: A surface structure of AlN substrate comprising:an AlN substrate,an intermediate layer disposed on the AlN substrate, anda metallized layer disposed on said intermediate layer, said intermediate layer comprising at least aluminum, nitrogen and oxygen. The metallized layer has a main component of one of Mo-Mn alloy, MO and W, and has a thickness of 1-20 .mu.m.This surface structure is produced by coating a surface of AlN substrate with metallizing layer components, heat treating the resultant coated substrate at a temperature of 200.degree.-500.degree. C. under an oxidizing atmosphere, and further heating the heat treated coated substrate at a temperature of 1200.degree.-1400.degree. C. under a nonoxidizing atmosphere having a dew point of -35.degree. to 5.degree. C.

Abstract: Ceramic sintered mass having a mean grain size of no more than 3 microns of high toughness even at high temperatures is obtainable, the mass comprising 30-99.5% by weight of a component A as defined below and the balance being a component B as defined below:Component A: zirconia having a tetragonal and/or cubic system content of no less than 90% by weight, with the proviso that the tetragonal/cubic system ratio by weight is no less than 0.25, said zirconia including a stabilizer of Y.sub.2 O.sub.3, CaO, MgO, etc.Component B: one or more of borides, carbides and nitrides of Al, Si and an element in the groups 4a, 5a and 6a of the periodic table, and Al.sub.2 O.sub.3.The balance may incorporate a further component C, such as SiO.sub.2, Fe.sub.2 O.sub.3 and TiO.sub.2 and the like of no more than 3% by weight in the sintered mass.

Abstract: A high toughness sintered body is described, consisting essentially of from 40 to 99.5% by weight of Component A, and 0.5 to 60% by weight of Component B, wherein the mean grain size of the sintered body is 3 microns or less, and Components A and B are as follows:Component A: ZrO.sub.2 containing a stabilizer, such as Y.sub.2 O.sub.3, CaO, and MgO, in which the fraction of the tetragonal and cubic ZrO.sub.2 constitutes at least 90% by weight, and the ratio of the tetragonal ZrO.sub.2 to the cubic ZrO.sub.2 is at least 1/3; andComponent B: at least one of Al.sub.2 O.sub.3 and TiN, with impurities being 3% by weight or less of SiO.sub.2, 0.5% by weight or less of Fe.sub.2 O.sub.3, and 0.5% by weight or less of TiO.sub.2, provided that the total amount is 3% by weight or less.

Abstract: A method for manufacture of a high toughness sintered body, characterized by sintering a shaped body of a mixed powder consisting essentially of from 40 to 70% by weight of a first component of powdered ZrO.sub.2 containing at least one stabilizer selected from the group consisting of Y.sub.2 O.sub.3, CaO, and MgO and having an average particle diameter of not more than 1.mu. and from 30 to 60% by weight of a second component of powdered .alpha.-Al.sub.2 O.sub.3 having an average particle diameter of not more than 1 .mu.m, which mixed powder may also contain not more than 3% by weight of SiO.sub.2, not more than 0.5% by weight of Fe.sub.2 O.sub.3, or not more than 0.5% by weight of TiO.sub.2 in a combined proportion of not more than 3% by weight at a temperature in the range of from 1400.degree. C. to 1600.degree. C. under normal pressure thereby producing a sintered body wherein at least 90% by weight of ZrO.sub.

Abstract: A process for producing a ceramic body suitable for surgical implantation that has high strength and toughness and good compatibility with bone material. A porous material is provided by semi-sintering a ceramic compact. The pores in the surface of the porous material are filled with a first powder of either tricalcium phosphate or apatite or both, or with a material of the fine powder and a powder of a material substantially the same as the material of the ceramic compact. The porous material is then fired at the sintering temperature of the ceramic compact. Following sintering, the surface of the porous material is coated with a fine apatite powder or a finally pulverized mixture of apatite and a calcium phosphate base frit. The resulting assembly is then fired at a temperature up to about 1,350.degree. C.