Abstract: There is provided a ceramic matrix composite whose strength is less degraded even in a high-temperature range at, especially, 1,400.degree. C. or higher, and a method of manufacturing the ceramic matrix composite. The ceramic matrix composite in which reinforcements are arranged in a ceramic matrix to be combined to the ceramic matrix is characterized in that the main component of the ceramic matrix consists of silicon carbide and molybdenum silicide based compound, the density ratio of the matrix is 90% or higher.

Abstract: In fiber composite ceramic containing reaction sintered SiC as a matrix and having BN-coated SiC continuous fibers as composite fibers, the thickness of the BN coating need not be especially made large, and a sliding effect during growing of cracks can be improved, i.e., breakdown energy can be increased. A method of manufacturing fiber composite ceramic in which large number of BN-coated SiC fibers covered with a BN coating are gathered to form yarns, or yarns are woven to form a two-dimensional or three-dimensional fabric, and a preform is formed by the yarns or the fabric, C powder is arranged in a gap portion between fibers of the preform to form a compact, a molten Si is impregnated into the compact to form an SiC matrix between fibers. A region having a high B concentration is formed around the SiC fibers before the preform is impregnated with the molten Si, and B in the region is solid-solved in Si during reaction sintering to suppress B in the BN-coated SiC fibers from being solid-solved in Si.

Abstract: A fiber reinforced ceramic matrix composite is disclosed which comprises a ceramic matrix and a fiber preform integrally assembled therein, the fiber preform comprising a braided fabric derivable from braiding a yarn which is composed of a plurality of fiber bundles formed of a plurality of monofilaments bundled together, the braided fabric being present in a volume fraction of fiber (Vf) of 10 to 40% by volume based on the total volume of the ceramic matrix composite. The yarns (fiber bundles) may preferably be disposed in oblique relation to each other. Initial matrix cracking strength, crack propagation resistance and fracture energy are greatly increased. Fiber preforms having a complicated shape can be easily obtained.

Abstract: A ceramic matrix composite material comprising a matrix containing silicon carbide as the primary component and silicon nitride as the secondary component is disclosed. The silicon nitride includes not more than 1% by weight of iron and reinforcements mixed and dispersed. The ceramic matrix composite material is manufactured, for example, by forming a matrix containing reaction sintered silicon carbide as the primary component and nitriding the free metal silicon produced in the sintering process so that the free metal silicon will be converted to fine silicon nitride particles. Said metal silicon used for reaction sintering already contains iron. These processes enable the containing of a comparatively large amount of reinforcements, as well as the improvement of heat resistance of the sintered compact and the suppression of the deterioration of reinforcements.

Abstract: A blade for the use of a rotary compressor includes a sintered body composed of 50 to 98.5 wt. % of zirconia, 1 to 49.5 wt. % of alumina and the reminder including 0.5 to 10 wt. % of a stabilizing material. The stabilizing material is comprised of at least one selected from magnesia, calcia, ceria and an oxide of an rare-earth metal and the grain size of the sintered body is less than 3 .mu.m. The zirconia in the sintered body is substantially formed with a tetragonal structure or a mixture of tetragonal and cubic structures.

Abstract: A ceramic matrix composite material comprising a matrix containing silicon carbide as the primary component and silicon nitride as the secondary component is disclosed. The silicon nitride includes not more than 1% by weight of iron and reinforcements mixed and dispersed. The ceramic matrix composite material is manufactured, for example, by forming a matrix containing reaction sintered silicon carbide as the primary component and nitriding the free metal silicon produced in the sintering process so that the free metal silicon will be converted to fine silicon nitride particles. Said metal silicon used for reaction sintering already contains iron. These processes enable the containing of a comparatively large amount of reinforcements, as well as the improvement of heat resistance of the sintered compact and the suppression of the deterioration of reinforcements.

Abstract: Sintered bodies with the primary phase of .beta. and/or .alpha. prime sialon. In the sialon phase which is the primary phase, hafnium oxide and silicon carbide are dispersedly contained as dispersion phases. 1 to 60 parts by weight of hafnium oxide are contained in 100 parts by weight of the primary phase. 5 to 30 parts by weight of silicon carbide are contained in 100 parts by weight of the primary phase. Hafnium oxide suppresses decrease of sintering characteristic which is caused by silicon carbide. Thus, a large amount of silicon carbide can be added, thereby improving the fracture toughness value.

Abstract: A ceramic sinter whose mother phase substantially satisfies a sialon composition. This sialon containing ceramic sinter contains at least one kind of compound selected from the group of oxides, carbides, nitrides, and silicides of hafnium, niobium, or titanium in the range of from 0.2 to 40 weight %. The compound of hafnium, niobium, or titanium is present independently in the mother phase in particle-dispersive form. The dispersed particles contribute to improving the mechanical strength, fracture toughness, and heat impact resistance because the sinter body is reinforced by dispersion. The sialon containing ceramic sinter is so excellent in high-temperature properties that it is suitable for use in high-temperature structural materials. Further, a .beta.

Abstract: A ceramic sintered body having a Young's Modulus of not less than 1,600 kg/mm.sup.2 produced by sintering 1 to 10 weight % of magnesium oxide, 0.5 to 10 weight % of silicon oxide, the remainder being substantially aluminum titanate.

Abstract: This invention relates to a metallizing composition capable of forming an electroconductive coating of satisfactory adherence properties on the surface of a sintered ceramic article, particularly on a sintered silicon nitride type ceramic article. The metallizing composition contains metal salts of tungstic acid and/or molybdic acid and a metal of Group IVb of the Periodic Table of Elements or a compound thereof. The electroconductive coating of high adherence properties is formed by applying the metallizing composition on a sintered ceramic article and drying the deposited layer of the composition in air, heating the dried layer, and firing the layer in a non-oxidizing atmosphere. The metallizing composition is suitable for the formation of the electroconductive coating on a complexly shaped sintered ceramic article such as, for example, on the inner surface of a hollow ceramic article.