Role of tensile elastostatic loading on atomic structure and mechanical properties of Zr_(55)Cu_(30)Ni_5Al_(10) bulk metallic glass

摘要

In this work, the pre-tensile elastostatic loading with low stress values (5%-20% sigma(y)) was used to rejuvenate Zr55Cu30Ni5Al10 bulk metallic glass (BMG). The atomic pair density function analysis shows that the rejuvenation evolution is accompanied with a significant disordering of short and medium atomic scales in the BMG structure. The results also indicate that the decreasing rate of annihilation in Cu-Zr pairs under rejuvenation is higher than Zr-Zr and Zr-Al pairs. In general, it is suggested that the interaction of stress domains under elastostatic loading is the main reason for disordering during the rejuvenation evolution. The compression test reveals that a brittle-to-ductile transition is happened from as-cast sample to the rejuvenated ones. Moreover, it is found that the serrations in the plastic region of stress-strain curves of highly-rejuvenated samples show a self-organized critical state. As a whole, with increase in pre-tensile elastostatic loading value, the structural rejuvenation enhances and the homogeneous plasticity improves.