Interaction of Edge Dislocation With Stacking Fault Tetrahedron in Cu

Abstract

This paper reports an anomaly in the yield strength of dislocation interacting with stacking fault tetrahedra (SFT) in Cu, reveals atomic mechanisms that are responsible for the anomaly, and further shows the thermodynamic driving force for the atomic mechanisms to prevail. Instead of monotonically increasing with the area of intersection cross-section, the yield strength first increases and then decreases with the area. The decrease, or the anomaly, is due to a change of atomic mechanism of the interactions—the SFT goes through a morphological transformation. The thermodynamic driving force for the transformation derives from the competition between the elastic energy of dislocations and the stacking fault energy.