On the infiltration behavior of Al, Al-Li and Mg meltas through SiC_p bed

Abstract

Aluminum, Al-Li (8090) and Mg matrix composites with uniform distributions of SiC_p reinforcement have been prepared by the vacuum infiltration technique. The infiltration kinetics have been found to increase in the order of Al, Al-Li and Mg. The Al-Li alloy and Mg as matrix materials have shown improved wettability with SiC_p in comparison to Al, leading to enhanced infiltration kinetics and reduced reinforcement degradation in the former cases. The infiltration kinetics are insensitive to preheat temperature beyond a critical temperature, which is close to the melting point of the matrix. A marginal improvement in infiltration kinetics could be obtained with Cu and Ni coating on SiC and on its dynamic oxidation. The improvement is significant at a higher preheat temperature of SiC. The Vickers hardness, measured on the SiC particles, has been shown to be an index of the strength of the interface between the matrix and reinforcement in the composite.