Degradation of Al₂O₃-SiC-Al composites prepared by the oxidative growth of Al-alloys into SiC particulate

Composites of Al₂O₃-SiC-Al have been prepared by the oxidative infiltration of Si-free aluminium alloys into SiC particulate that were coated with spray-pyrolysed alumina. Moisture degradation studies were carried out to evaluate the extent of formation of aluminium carbide, the formation of which was also inferred by the determination of the residual silicon content in the composite. The efficiency of the coating technique in protecting the SiC from attack by the melt was evaluated at 1000 and 1200°C.