Effects of shear strain on shock response in single crystal iron

B Li and MT Liu and BQ Luo and C Fan and Y Cai and F Zhao and L Wang, JOURNAL OF APPLIED PHYSICS, 135, 145902 (2024).

DOI: 10.1063/5.0196203

With large-scale non-equilibrium molecular dynamics simulations and in situ x-ray diffraction analysis, we conducted a systematic investigation into the effects of pre-existing shear strain (gamma(xy)) on the shock response of single crystal iron. Our findings reveal significant effects of gamma(xy) on the deformation of the crystal structure during shock loading, leading to noticeable alterations in the propagation of shock waves. Specifically, during the elastic stage, the presence of gamma(xy) results in a reduction of shock strength, consequently diminishing the magnitude of elastic lattice strain (epsilon(e)). In the plastic stage, gamma(xy) stimulates the alpha- epsilon phase transformation, and structure deformation undergoes a transition from the sequential activity of dislocation-to-transformation to the synchronous activity of dislocation and transformation. This transition inhibits the propagation of plastic waves and consequently broadens the elastic regime. Additionally, the introduction of gamma(xy) activates different slip systems, as it alters the corresponding resolved shear stress. Concurrently, the presence of gamma(xy) triggers the activation of different high-pressure phase variants. Our investigation sheds light on the fundamental physics of iron under shock compression and the influence of pre-existing shear strain on its behavior. (c) 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license(https://creativecommons.org/licenses/by/4.0/).

Return to Publications page