MECHANICAL-PROPERTIES OF SIC FIBER AFTER IMMERSION IN MOLTEN ALUMINUM

Low oxygen SiC fiber/Al interfacial reactivity was evaluated in compar ison with that of an usual Sic fiber/Al interface. Chemical compositio n of low oxygen SiC fiber was Si:62.4, C:37.1, O:0.5 mass% and that of a usual SiC fiber was Si : 63.7, C : 35.8, O : 12.3 mass%. The outcom es of this study can be summarized as follows: (a) No product was dete cted at the low oxygen SIC fiber/Al interface. (b) The low oxygen SiC fiber-reinforced Al composite was higher corrosion resistance, and low er strength deterioration on compared with the usual SiC fiber-reinfor ced Al composite. (c) Al atoms diffuse into low oxygen SiC fiber. duri ng dipping into a molten Al with the diffusivity of 6 x 10(-15) m(2)/s . (d) In the initial stage of interfacial reaction, low oxygen SIC fib ers are not eroded, but a needle-shape Al4C3 phase forms on the fiber surface. On the other hand, the SiC fiber can be eroded by the Al4C3 f ormation, when long time dipping in the molten Al under unfavorable co nditions.