Mechanical Properties of SiC Fiber after Immersion in Molten Aluminum

Low oxygen SiC fiber/Al interfacial reactivity was evaluated in comparison with that of an usual SiC fiber/Al interface. Chemical composition of low oxygen SiC fiber was Si: 62.4, C: 37.1, O: 0.5mass% and that of a usual SiC fiber was Si: 63.7, C: 35.8, O:12.3mass%. The outcomes of this study can be summarized as follows: (a) No product was detected at the low oxygen SiC fiber/Al interface. (b) The low oxygen SiC fiber-reinforced Al composite was higher corrosion resistance, and lower strength deterioration on compared with the usual SiC fiber-reinforced Al composite. (c) Al atoms diffuse into low oxygen SiC fiber during dipping into a molten Al with the diusivity of 6×10-15m2/s. (d) In the initial stage of interfacial reaction, low oxygen SiC fibers 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 formation, when long time dipping in the molten Al under unfavorable conditions.