Dynamic response and damage evolution of Zr-based bulk metallic glass under shock loading

Abstract

• The hugoniot elastic limit (HEL) and the spalling strength (σ sp ) were measured as 7.09 GPa and 2.28 GPa. • The failure mode changed from spallation to fragmentation caused by the combination of spalling cracks and longitudinal cracks. • The elastic wave front causes pre-damage to the BMG, leading to a decrease in its spalling strength. Dynamic response and damage evolution of Zr 70 Cu 13 Ni 9.8 Al 3.6 Nb 3.4 Y 0.2 bulk metallic glass (Zr-based BMG) under impact pressure ranging from 4.03 GPa to 27.22 GPa were studied. The Hugoniot Elastic Limit (HEL) and the spalling Strength ( σ sp ) were measured as 7.09 GPa and 2.28 GPa, and the curve of impact velocity ( D ) and particle velocity ( u ) were also obtained. Under the strain rate of ~10 5 s −1 , local crystallization phenomenon was observed. As increasing the impact pressure, the failure mode of Zr-based BMG changed from spallation to fragmentation caused by the combination of spalling cracks and longitudinal cracks. Cone-cup structures were also observed in the internal spalling zone via nano-CT characterization. When increasing the impact pressure, the thickness of Zr-based BMG increased after impact and the remelting and cladding layers were also observed on the fracture surfaces. The fragments of the specimen were welded after impact due to the high temperature remelting, which causes plastic deformation of Zr-based BMG under shock loading.