Phase-field simulation of diffusion-controlled coarsening kinetics of γ^’ phase in Ni–Al alloy

Abstract

Abstract Morphology evolution and coarsening kinetics of γ ’ (Ni 3 Al) precipitates in Ni–Al alloy were investigated quantitatively using the interface diffusion-controlled, the bulk diffusion-controlled, and the interface diffusion-controlled elastic strain models. By calculating the γ ’ phase number density, volume fraction, and particle radius, the effects of diffusion and elastic strain on the γ ’ phase growth and coarsening were clarified. The coarsening rate constants are smaller in the bulk diffusion-controlled and the interface diffusion-controlled elastic strain models than those of the interface diffusion-controlled model, which is due to the long-range diffusion of Al atoms and the retardant effect of coherent strain between the γ ’ and γ phases, respectively. The linear fitting on the cubic exponent shows the comparable associate coefficient that gives no superiority to the different models in Ni–Al alloy.