Simulation study of effects of initial particle size distribution on dissolution

Dissolution kinetics of gamma' particles in binary Ni-Al alloys with different initial particle size distributions (PSD) is studied using a three, dimensional (3D) quantitative phase field model. By linking model inputs directly to thermodynamic and atomic mobility databases microstructural evolution during dissolution is simulated in real time and length scales. The model is first validated against analytical solution for dissolution of a single gamma' particle in ID and numerical solution in 3D before it is applied to investigate the effects of initial PSD on dissolution kinetics. Four different types of PSD, uniform, normal, log-normal and bimodal, are considered. The simulatior results show that the volume fraction of gamma' particles decreases exponentially with time, while the temporal evolution of average particle size depends strongly on the initial PSD. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.