| 摘要 |
PURPOSE:To inexpensively obtain a composite material having high strength and excellent machinability by using an alumina short fibers assemblage contg. Al2O3, SiO2 and other components at specific ratios, contg. a specific ratio of mullite crystals and contg. other components as well except alpha-A2O3, as reinforcing fiber. CONSTITUTION:The assemblage of the alumina short fibers contg. 65-95wt% Al2O3, 35-5wt% SiO2, 0-10wt% other components, >=12wt% mullite crystals and contg. the components except the mullite crystal at least part of which are components except alpha-Al2O3, is used as the reinforcing fiber. The quantity of the nonfibrillated particles of >=150mu grain size contained in the assemblage of the alumina short fibers is made <=0.2wt% and the average fiber diameter is made above 1.5-5.0mu. The average fiber length is about 20mu-3mm and the volumetric rate thereof is 5-40%. Al, Mg or the alloy essentially consisting thereof is used as the matrix metal to form the composite material. The inexpensive composite material having high strength is thus obtd.
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