Theoretical and experimental study on ultrasonic dispersion of nanoparticles for strengthening cast Aluminum Alloy A356

Abstract

Aluminum alloy A356 is of significance for numerous applications. The mechanical properties of A356 would be enhanced considerably if reinforced by thermodynamically- stable nanoparticles. However, it is very challenging to disperse nanoparticles uniformly in A356 melts for casting A356 nanocomposites. In this study, ultrasonic cavitation effect was proposed to disperse SiC nanoparticles in A356 melts before casting. The novel method was theoretically studied and then experimented. With only 1.0wt.% nano-sized SiC reinforcement (about 30nm), the ultimate tensile strength and yield strength of the aluminum alloy A356 were enhanced significantly while the ductility was retained. The study on micro/nano structures of the nanocomposites validates that a uniform distribution and effective dispersion of nanoparticles in A356 matrix were achieved. Moreover, a good bonding between the SiC nanoparticles and the Al matrix was obtained. This study paves a way for high volume solidification processing of metal matrix nanocomposites for industrial applications.