Liquid phase stratification induced by large temperature gradient during spinodal decomposition in Fe–Cr alloys: A phase-field study

Abstract

The spinodal decomposition in Fe-40at.%Cr binary alloy is numerically studied by implementing the phase-field model based on Cahn–Hilliard equation. Effects of different temperature gradients on the solute distributing characteristics during the spinodal decomposition are investigated. In the system with a temperature gradient, the phase decomposition happens gradually from low temperature to high temperature, and a metastable stratification is achieved with specified temperature distribution. The critical temperature and corresponding temperature gradient are specified for the obvious solute stratification in the binary Fe–Cr alloy. The kinetics of the solute diffusion during the spinodal decomposition is discussed to reveal the liquid phase stratification induced by the anisotropic diffusion with the nonuniform temperature field. Therefore, tailoring the heat treatment during the spinodal decomposition in Fe–Cr binary alloys might be an efficient way to obtain nanometer coherent microstructures with specified solute distribution.