THE MECHANISM OF SPONTANEOUS INFILTRATION OF AL-SI ALLOY INTO SIC PREFORM IN AIR

Rapid, spontaneous infiltration can be achieved by dipping a SiC prefo rm that contains pyrolyzed carbon into an Al-Si alloy bath in an open air environment. The mechanism for infiltration is investigated in the present work by studying the effects of several relevant parameters o n the infiltration process. Experimental results have shown that the r equirements for rapid spontaneous infiltration are an infiltration tem perature higher than 1400 degrees C, the presence of a pyrolyzed carbo n, and the presence of SiC particle in the preforms. The concentration of Si in the alloy does not have significant influence on the infiltr ation rate, but it strongly affects the resulting microstructures in t he infiltrated composites.