The structural evolution of misfit dislocation networks at γ/γ′ phase interfaces in Ni-based single crystal superalloys under tensile loading and temperatures was simulated by molecular dynamics. From the simulation, it was found that, with increasing load or temperature, the patterns of dislocation networks on the (100), (110) and (111) phase interfaces changed from regular to irregular or disappear. Under the same load and temperature, the dislocation networks of the different phase interfaces showed different degrees and patterns of damage. The density and stability of the dislocation networks decreased with increasing temperature. When the interfacial dislocation networks become more regular, the γ/γ′ interfaces become more stable. The simulated results were supported by related experimental findings. Moreover, based upon molecular dynamics simulations, the averaged stress–strain responses for different phase interfaces under loading were presented. The results indicate that the combined influences of temperature and load play an important role for the structure evolution of misfit dislocation networks at γ/γ′ phase interfaces of Ni-based superalloys.

Molecular Dynamics Simulation of the Structural Evolution of Misfit Dislocation Networks at γ/γ′ Phase Interfaces in Ni-Based Superalloys. W.P.Wu, Y.F.Guo, Y.S.Wang, R.Mueller, D.Gross: Philosophical Magazine, 2011, 91[3], 357-72