Hetero-Boundary-Affected Regions in Heterostructured Materials

Abstract

Hetero-boundary-affected regions (HBARs) are widely observed in metallic materials and believed to play important roles in heterostructured materials that are currently attracting broad attention due to their superior mechanical properties which defy the conventional rule-of-mixtures. Here, we perform a series of discrete dislocation dynamics (DDD) simulations to confirm the existence of HBARs and investigate the mechanisms of their formation, growth, and evolution during plastic deformation. Our DDD simulations reveal that the HBARs are well characterized by a heterogeneous dislocation microstructure with distinct stress/strain gradients that depend on interface penetrability and applied strain. Furthermore, it is shown that the HBARs can significantly affect the mechanical responses of materials. This study aimed to provide a mechanistic basis to understand the formation mechanism of HBARs, which is critical for physics-based modeling of the mechanical behavior of heterostructured materials.