Deformation Behavior of the Zr53.5Cu26.5Ni5Al12Ag3 Bulk Metallic Glass Over a Wide Range of Strain Rate and Temperatures

The stress–strain relations for the Zr53.5Cu26.5Ni5Al12Ag3 bulk metallic glass (BMG) over a broad range of temperatures (room temperature to its supercooled liquid region) and strain rates (10−4 to 10−1 s−1) were established in uniaxial compression using a thermal-mechanical simulation system. The superplastic flow was seen above its glass transition temperature (Tg = 694 K) and strain rates of up to 10−1 s−1 from the variation of stress–strain curves. A deformation map of strain rate vs temperature of Zr53.5Cu26.5Ni5Al12Ag3 was obtained, which was mainly composed of homogeneous and inhomogeneous deformation regions, the former featuring either Newtonian or non-Newtonian flow while the latter characterizing linear elastic behavior followed by shear localization, respectively. A phenomenological constitutive equation used to describe a master curve of viscosity with respect to the strain rate was obtained by fitting the experimental results, which determines the viscosity of the present alloy at the temperature near and above Tg. The results show the Zr53.5Cu26.5Ni5Al12Ag3 BMG is the subject suitable for net shape forming process at the supercooled liquid region.