Concurrent interface shearing and dislocation core change on the glide dislocation-interface interactions: a phase field approach

Abstract

Strengthening in nanoscale metallic multilayers is closely related to the glide dislocation-interface interaction. The interface can be sheared by the stress of the approaching glide dislocation with its core changed. How the concurrent interface shearing and the dislocation core change influence such interaction dominated strength is studied using three dimensional phase field microelasticity modeling and simulation. The simulated results show that when the glide dislocation is close to or away from the interface, the width of its core changes abruptly in accompany with the interface shear zone broadening or shrinking, respectively. A wider interface shear zone is developed on the interface with a lower shear strength, and can trap the glide dislocation at the interface in a lower energy state, and thus leads a stronger barrier to dislocation transmission. The results further show that the continuum model of the dislocation without the core-width change underestimates the interfacial barrier strength especially for the glide dislocation transmission across weak interfaces.

Keywords

• strength
• metallic multilayer
• phase field
• dislocation
• interface shear