The Effect of Reinforcement on Superplastic Flow in Powder-Metallurgy Processed Aluminium Matrix Composites

摘要

"Particle weakening" phenomenon was observed in 2124 Al composites as well as in 6061 AJ composites. At high temperatures where superplastic flow controls the plastic flow, composite is weaker than unreinforced matrix alloy even after compensating for grain size and threshold stress. Furthermore, such strength differential between the two materials is temperature dependent, which increases with increasing temperature. This may resulted from the presence of liquid phase at the reinforcement/Al matrix whose amount is expected to increase with increase in temperature.