Orientation-Dependent Morphology and Evolution of Interfacial Dislocation Networks in Ni-Based Single-Crystal Superalloys: A Molecular Dynamics Simulation

Abstract

In this paper, the morphology and evolution of interfacial dislocation networks of (100), (110) and (111) interphases of Ni-based single-crystal superalloys are studied by molecular dynamics (MD) simulations. Three-dimensional cubic-type and sandwich-type models are chosen to explore the orientation-dependent morphology of dislocation networks, and their respective advantages and disadvantages are compared. From the simulations, it is observed that various lattice orientations and model types lead to different morphologies of dislocation networks. Based on the analysis of average atomic energy and dislocation characteristics, the (100) orientation model has a more regular dislocation network, lower energy and better stability than the (110) and (111) orientation models after MD relaxation, which are supported by previous experimental and numerical simulations. Moreover, the cubic-type model has lower energy and better stability than the sandwich-type model. This will be helpful for choosing a more appropriate and reasonable model for simulating the interfacial dislocation networks of Ni-based single-crystal superalloys.