Effect of Zener-Hollomon parameter on the flow behavior of Zr-based metallic glass

The constitutive behavior of Zr-based metallic glass ribbon around the glass transition temperature was investigated. The Zener-Hollomon equation was adopted to predict the flow stresses. The experimental results show that an exponent value of 0.75 and activation energy magnitude of 343 kJ/mol can be used in the hyperbolic sine model to predict the flow stress response of the steady-state stage. The activation energy is consistent with the free volume theory (335 kJ/mol). It is observed that the flow stress during steady-state is independent of the previously strain rate history and is only sensitivity to the current strain rate. A Z-parameter constitutive model to describe the hot deformation behavior of Zr-based metallic glass is developed.