Computer simulation of phase decomposition in the regular solid solution based upon the non-linear diffusion equation

A new Fourier expression of the Cahn-Hilliard's flux equation is proposed, where the regular solution approximation is adopted as the chemical free energy of solid solution and the mobility is defined as a function of solute composition. The results of the computer simulation of phase decomposition, derived on the basis of the new method, are in accord with the prediction from the phase diagram which is theoretically given by the free energy of the regular solution approximation. This calculation method is applicable to the actual alloy systems, because the phase diagrams have usually been evaluated, based on the regular solution or the modified regular solution model.