Microhardness studies on Stir Cast AA7075-Si3N4 Based Composites

Abstract

In this paper the effect of silicon nitride reinforcement on microhardness on AA7075-Si3N4 has been studied. Five different samples with varying weight percentage (0, 2, 4, 6, and 8) of silicon nitride have been fabricated via stir casting route. Apart from microstructural evaluation, microhardness has been studied at different indentation loads and for different dwell times. The microstructural results showed a grain refinement with the increase in the silicon nitride content. The results exhibited that with the increase in silicon nitride reinforcement the microhardness improved. The microhardness showed a decreasing trend with the increase in indentation load and a decreasing trend with the increase in dwell time.