Twin Transmission Across Grain Boundaries in Ma

摘要

Transmission of {1012}{T011} mechanical twins across grain boundaries in Mg is a mechanism that can facilitate shear accomodation but also provide a path for failure via intergranular crack propagation. Until recently the twin research has focused on a 2D characterization of intra-granular propagation and intergranular transmission along the forward propagation direction. Recent 3D studies of the twin domain interface reveal a faceted structure, anisotropic mobility, and a relative easiness of lateral twin propagation (as opposed to forward or normal propagation). Here we describe a study of the forward and the lateral twin transmission into neighbors applying a variety of experimental and computational characterization techniques, namely: (1) statistical EBSD analysis of twin sections; (2) 3D Phase Field and Molecular Dynamic simulations of twins propgating and reacting with grain boundaries. This study improves our understanding of the transmission mechanisms in a 3D aggregate, and helps us to develop criteria for treating twin modeling in CP simulations.