The Effects of Temperature and Impact Velocity on the Shock Wave Response of Pore-Embedded Metallic Glasses

Abstract

In this work, the shock wave response of a pore-embedded CuZr metallic glass (PEMG) under different impact velocities (0.5–1.5 km/s) and initial temperatures (300–600 K) was evaluated through the molecular dynamics (MD) simulation. The results indicated that the nucleation and growth of nanoscale shear events around the pore were the dominant mechanisms for plastic deformation under the shock wave. It was also found that the increase in the impact velocity led to the filling of pore, which was due to the structural softening and the local temperature increment in the vicinity of pore. Moreover, the spall event originated from the formation and coalescence of tension transformation zones, leading to the formation of nanovoids in the system. At higher velocities, the spallation was accompanied with the formation of more nanovoids with smaller sizes, inducing the brittle failure in the system. The MD outcomes also showed that the increase in initial temperature decreased the shock pressure and flow shear stress and led to the smoother spallation in the PEMG.

Characterization of Plastic Deformation in CuZr Metallic Glasses Subjected to the Rolling Process

“…However, the poor ductility at room temperature is one of their drawbacks for application in the engineering systems [5][6][7]. It is generally accepted that the plastic deformation of MGs is occurred in the narrow sheared regions, named as shear bands, which is resulted from the sliding of energetically favorable defects under an external force [8][9][10]. Recently, many investigations have been conducted to mitigate the brittle behavior of MGs through the formation and interaction of multiple shear bands in the microstructure [11][12][13][14].…”

Mechanism of Imprinting Process in the Ni-P Metallic Glass Films: A Molecular Dynamics Study

“…Due to their disordered atomic structure, metallic glasses (MGs) typically exhibit superior mechanical properties and excellent viscous fow formability [9][10][11][12][13]. Hence, a great interest has been taken by researchers to employ this kind of metallic alloys in the NIL method [14][15][16].…”