Vickers-indentation-induced crystallization in a metallic glass

摘要

Crystallization preferentially occurs on the compressive sides of some metallic glasses due to bending, implying that stress state is a critical factor affecting the mechanically induced crystallization. However, the role of stress state in mechanically induced crystallization in metallic glasses is poorly understood. Here, we report on the crystallization kinetics in different deformed regions during Vickers indentation of Zr_(65)Al_(7.5)Ni_(10)Cu_(12.5)Ag_5 metallic glass. Our results indicate that the nucleation rate beneath the indenter tip is much higher than that under an indenter edge. It is revealed that the nucleation rate I (m~(-3) s~(-1)) and the effective compressive stress P (MPa) follow an expression I = exp(3.81+0.044 P), which agrees well with our experimental results. Our findings reduce the role of stress state in mechanically induced crystallization in metallic glasses, which is helpful in understanding the mechanism of mechanically induced crystallization.