Atomistic simulation for the γ′-phase volume fraction dependence of the interfacial behavior of Ni- base superalloy

By means of molecular dynamics (MD) and the modified analytic embedded-atom method (MAEAM), we investigate the effect of the gamma'-phase volume fraction (gamma'-VF) on the apparent interface energy, the critical thickness of the interface transition region (ITR) and the binding mechanism of the gamma/gamma' interface. The results indicate that the apparent interface energy increases linearly with the ITR width increasing. Then, by extrapolating the ITR width Delta l to zero, we can obtain the interface energy which is equal to the limiting value of the apparent interface energy. The volume fraction of the gamma'-phase has no influence on the interface energy and the critical thickness of the ITR. The interface energy is in reasonable agreement with the previous results and the critical value of the ITR width is about 1.7 nm which also agrees well with the experimental and theoretical ones. Finally, the gamma'-VF dependence of the apparent interface energy and the interface separation of the ITR with about 1.7 nm thickness are analyzed in more detail. The results reveal that the crystalline configuration of Ni-base superalloy (NBSA) with (60-70%) gamma'-VF is the stablest, which is similar to the previous investigations. (C) 2012 Elsevier B.V. All rights reserved.