Effect of shot peening on mechanical behavior of Zr-based bulk metallic glasses under monotonic and cyclic loading mode

Abstract

The mechanical behavior of as-cast and peened (Zr55Cu30Ni5Al10)99Y1 bulk metallic glass (BMG) under monotonic loading and cyclic loading mode was investigated. Abundant pre-existing shear bands were observed on the surface of the BMG after shot peening. It is suggested that shot peening can significantly enhance the compressive plasticity of the BMG. Interestingly, compared with the as-cast specimen, the peened specimen exhibits the similar yield stress of about 1850 MPa and fatigue limit of about 1095 MPa in stress range, but shorter fatigue life at high stress level. That is to say, shot peening has a great influence on the fatigue properties of BMG in high stress range, and has little influence on the fatigue properties of BMG in low stress range near fatigue limit. This is attributed to mutually competition between the positive effect and negative effect on the mechanical behaviors of BMG induced by shot peening, and which one of the two effects plays the dominant role depends mainly on the loading mode. The present study will give suggestion for the safe service of Zr-based BMG.