Effect of the initial temperature on the shock response of Cu50Zr50 bulk metallic glass by molecular dynamics simulation
Peng Wen, Brian Demaske, Douglas E. Spearot, Simon R. Phillpot, Gang Tao
Abstract
The effect of initial temperature on the shock response of Cu50Zr50 bulk metallic glass (BMG) is investigated by molecular dynamics simulations using the multiscale shock technique. The shock Hugoniot relationship of Cu50Zr50 BMG shows an obvious temperature dependence. At the Hugoniot elastic limit (HEL), the critical shear stress decreases with increasing initial temperature; this is modeled based on the activation of shear transformation zones. Shock at high temperatures shows a pressure-dependent HEL. The deformation map reveals that there are three deformation regimes under different shock intensities and temperatures: elastic, plastic, and shock-induced melting. The flow stress decreases with increasing initial temperature confirming that high temperatures reduce the shear resistance of the Cu50Zr50 BMG. At high temperatures and pressures, a shock-induced melting regime is identified using a diffusivity-based analysis.