Multiphase Ni–Cr–Al diffusion couples: A comparison of phase field simulations with experimental data

Microstructures in γ+β/γ diffusion couples made of Ni–Cr–Al alloys were investigated numerically in two dimensions using a phase field model. With experimental thermodynamic and mobility data from the literature as inputs, the model was used to predict the evolution of the precipitate morphology, the dissolution of the two-phase γ+β regions and the diffusion paths as functions of alloy composition The dissolution rates and diffusion paths obtained from the simulations were in general agreement with experimental data, although quantitative differences were found. Differences in the dissolution rates and diffusion paths could be directly related to differences in the predicted phase diagram and the phase diagram reported in the experimental study.