High temperature deformation behaviors of the Zr_63.36Cu_14.52Ni_10.12Al₁₂ bulk metallic glass

A systematic study on the thermal properties, deformation behaviors, and thermal workability of Zr_63.36Cu_14.52Ni_10.12Al₁₂ bulk metallic glass (BMG) was conducted in the supercooled liquid region (SLR) with strain rates ranging from 2.5 × 10⁻⁴ to 5 × 10⁻³ s⁻¹. The strain-rate jump experimental results show that the homogeneous deformation behavior transforms from non-Newtonian flow to Newtonian flow with decreasing strain rate as well as elevating temperature. In the framework of the Kissinger and free-volume model, this phenomenon can be explained by the transition state theory. The values of the activation volume and activation energy of the BMG are obtained, which are consistent with other BMGs. The optimum domain for thermal workability of the metallic glass has been located by the power dissipation efficiency map where the power dissipation efficiency is larger than 0.8.