Plastic deformation of bi-crystalline Zr-ZrH2

Abstract

By employing atomistic simulation, we investigated the deformation mechanism of the Zr-ZrH2 bi-crystal pillar containing coherent the Zr-ZrH2 interface under uniaxial compressive loading. The plastic deformation of the bi-crystalline sample first commences in the Zr part with tension twinning, followed by dislocation nucleation on the basal planes of the twinned area. Then plasticity transfers to ZrH2 with the assistance of lateral dislocation pile-up at the Zr side of the coherent Zr-ZrH2 interface, which promotes dislocation nucleation on <100>{001} slip system in ZrH2 side. The proposed deformation mechanism sheds light on the deformation behavior of inter-granular and trans-granular hydrides in the Zr matrix.