Effect of quenching rate on the microstructure and mechanical behavior of Ce75Al21Ga4 glassy alloy

Abstract

The present study deals with the structural and microstructural changes with respect to the quenching rate and their correlation with mechanical behavior of melt-spun Ce75Al21Ga4 glassy alloys. The ribbons of the alloy have been synthesized at different quenching rates obtained through different wheel speeds (44, 36, 29, 22 and 15m/s). The glass forming indicators and mechanical properties have been investigated at different quenching rates. The higher quenching rate obtained through high wheel speed (44, 36 and 29m/s) has led to phase separation giving rise to nano-amorphous domains in a glassy matrix while the lower quenching rate obtained through lower wheel speed (22 and 15m/s) produces nano-crystalline grains with size ranges from 25±1 to 120±1nm. It has been found that the size of the nano-amorphous domains decreases with decrease in wheel speed. The mechanical behavior has been studied using micro-indentation technique. The indentation test indicates that with the same chemical composition, the ribbons synthesized at slow quenching rate exhibits higher hardness and yield strength than those synthesized at faster quenching rate. The ribbons synthesized at 44m/s contains the large free volume and has the highest shear band density.