Effect of pre-straining on the structure and nano-mechanical properties of a CuZrAl bulk metallic glass

Pre-straining was carried out on a CuZrAl bulk metallic glass (BMG), in order to understand the physical correlation between its structural heterogeneity and nano-mechanical performance. As the pre-strain increases, the studied glass remains its amorphous structure whereas the degree of local order firstly decreases and then increases, yielding a minimum value at 10 % pre-strain, and the Helmholtz activation energy (ΔF*), shear transformation zone (STZ) volume, number of atoms in the STZ (N), and the nanohardness value exhibits a similar trend. The variation in the structure and thus mechanical performance induced by pre-straining has been interpreted from the viewpoint of free volume concept. The results obtained here can be beneficial for tailoring the structure and the corresponding mechanical properties of BMGs.