| 摘要 |
PROBLEM TO BE SOLVED: To obtain a composite material having high reliability to thermal impact by using an Al alloy contg. a specified amt. of Mg as a matrix and carbon fibers contg. a specified amt. of Si in the surface layer as a dispersing material and adding a specified amt. of carbonaceous binder which allows the dispersing material to stick and communicate with. SOLUTION: An Al alloy contg. 0.1 to 10 wt.% Mg is used as a matrix, carbon fibers contg. 5 to 40% Si in the surface layer are used as a dispersing material, and, moreover, a binder essentially consisting of carbon and allowing the dispersing material to stick and communicate with is added by a volume packing ratio of 10 to 60% to obtain a carbon fiber dispersed Al matrix composite material having high thermal conductivity and low thermal expansibility. Preferably, the carbon fibers as the dispersing material are two-dimentionally orientated in a random state to a direction in which the thermal expansion of the composite material should be suppressed and have a layer structure in the thickness direction. Furthermore, SiC is formed on the surface of the carbon fibers, an Si concn. distribution is which it reduces toward the inside is made, and its wettability for the Al alloy is improved.
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