Interaction between the edge dislocation dipole pair and interfacial misfit dislocation network in Ni-based single crystal superalloys

Abstract

Understanding the intrinsic strengthening mechanism is of great significance for microstructural design of Ni-based single crystal superalloys. In this paper, from an atomistic perspective, the interacting mechanism between edge dislocation dipole pair and interfacial misfit dislocation network has been elaborated. It is shown that a network of interfacial misfit dislocations can effectively impede the movement of matrix dislocations, accommodate and pile up the edge dislocation dipole pairs in Ni matrix. Furthermore, we have systematically elucidated the influence of loading rates on the stimulating period of edge dislocation dipole pairs and stiffness of Ni/Ni3Al substrate. These findings provide a better understanding of the interfacial strengthening mechanism of Ni-based single crystal superalloys.