Phase-field simulation of diffusion=controlled coarsening kinetics of γ′ phase in Ni-Al alloy

Morphology evolution and coarsening kinetics of gamma' (Ni3Al) 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 gamma' phase number density, volume fraction, and particle radius, the effects of diffusion and elastic strain on the gamma' 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 gamma' and gamma 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.