Deformation and cavitation behavior of a high-strain-rate superplastic Al2009/20SiC_wcomposite

In this paper, the deformation and cavitation behavior of a high-strain-rate superplastic Al2009/20SiCwcomposite was examined at temperatures ranging from 753 to 823 K, and at the initial strain rates from 1.67×10-3to 1.67×100s-. A maximum elongation of approximately 250% was obtained at an optimum initial strain rate of 3.33×10-1s-1and a temperature of 808 K, which was slightly higher than the partial melting temperature of the composite. The cavitation behavior of the composite was compared with typical superplastic aluminum alloys. It was considered that the presence of the liquid phase in the composite can effectively relax the stress concentration caused by grain boundary sliding, and hence, limited the growth of cavitation.