Influence of processing parameters during disintegrated melt deposition processing on near net shape synthesis of aluminium based metal matrix composites

Abstract

This paper addresses the influence of processing parameters on the near net shape synthesis of Al-SiC particle reinforced metal matrix composites by the disintegrated melt deposition technique. The processing parameters that were investigated include stirring speed during reinforcement addition, holding and stirring times following reinforcement addition, and total flight distance. The effect of the weight fraction of SiC incorporated was also studied. Maximum incorporation of the reinforcement was achieved by dispersing SiC particles in liquid aluminium with an impeller at a stirring speed of 500 rev min-1. Composite porosity levels were minimised for holding and stirring times following SiC addition of 15 and 5 min, respectively, and for a total flight distance of 450 mm. Composite porosity levels were increased with increasing weight fractions of SiC incorporated. The results obtained clearly demonstrate the dependence of composite porosity levels on weight fraction of reinforcement incorporated, total flight distance, and holding and stirring times following addition of SiC particles, and reinforcement incorporation on stirring speed. © 1999 IoM Communications Ltd.