Combined effect of melt thermal treatment and Sr modifier on microstructure and mechanical properties of hypereutectic Al-14Si alloy

Abstract

This research aimed to investigate the combined effect of melt thermal treatment and Sr modifier on microstructure and mechanical properties of hypereutectic Al-14Si alloy. Various characterization techniques and testings such as optical microscopy, scanning electron microscopy, tensile test and hardness test were carried out to evaluate the samples. The results showed that the melt thermal treated alloys have a more refined primary Si phase and modified eutectic Si structure than that of the conventional cast alloys. This led to a considerable improvement in tensile strength, hardness and ductility in the melt thermal treated alloys. The mean size of primary Si and eutectic Si was lesser in the case of the sample that had undergone both melt thermal treatment and Sr-modification than the only Srmodified alloy. These lead to a significant improvement in mechanical properties of the alloy treated by both melt thermal treatment and Sr-modifier than only Sr-modified alloy.