Viscoplastic deformations and compressive damage in an A359/SiC_p metal-matrix composite

摘要

Recent work by the authors has examined the high-strain-rate compression of a metal-matrix composite consisting ofan A359 Al alloy matrix reinforced by 20 vol. percent of siliconcarbide particulates (SiC_p). The work-hardening that is observedin the experiments is much lower than that predicted by analyticaland computational models which assume perfect particle-matrixinterfaces and undamaged particles. In this work, we show that thediscrepancy is a result of particle damage that develops within theA359/ SiC_p composite under compression. The evolution ofparticle damage has been characterized using quantitativemicroscopy, and is shown to be a function of the applied strain. Asimple analytical model that incorporates evolving damage withinthe composite is proposed, and it is shown that the analyticalpredictions are consistent with the experimental observations overa wide range of strain rates.