Shock induced damage and fracture in single crystal rhenium at different crystal orientations

Abstract

Rhenium (Re) is usually used in extreme operating conditions such as high speed impact due to its superior mechanical and physical properties. Spallation is a typical dynamic tensile rupture phenomenon. However, the shock reaction mechanism and law of Re have not been fully established. In this research, large-scale molecular dynamics simulation was applied to investigate the shock-induced damage and fracture of single-crystal Re in different crystal orientations under loading speeds ranging from 0.5 to 3.0 km/s. Our study reveals that the response is highly anisotropic under different load orientations. It has been discovered that the material heats up during wave propagation at a higher loading velocity, decreasing the spall strength. Additionally, [2-1-10] has the lowest spall threshold strength and [0001] has the best resistance to spall. The process of nucleation, growth, and coalescence of the voids can be observed by focusing on the examination of the shock-induced response of the [0001] crystal orientation. We also found that a large spall region results from higher shock intensity and temperature, which also cause a change in fracture morphology from classical spallation to micro-spallation with less anisotropy caused by atomic arrangement. The findings of this study add to a better knowledge of the mechanism and attributes of shock-induced damage on single-crystal Re under ultrahigh strain rate loading.