Continuum Separation of Nanoscale Phase in Thermal Aging Fe-Cr Alloys: Phase-Field Simulation and Experiment

The separation of Cr-enriched α ′ phase in Fe-(25–45) at.% Cr alloys is studied from the metastable region to the unstable region. The three-dimensional phase-field simulation shows a similar morphology with the transmission electron microscopy micrographs, and the quantitative simulation of particle size and particle number density have a good accordance with the present and the referred experimental results, with the microhardness of the alloy increasing simultaneously with the simulated volume fraction of the α ′ phase. The mechanisms of phase separation were clarified by the interface composition evolution of the α / α ′ phase, and a transitional characteristic from nucleation and growth to spinodal decomposition is shown in the 30 at.% Cr alloy aged at 750 K. The combination of quantitative simulation and experimental results demonstrates the ability of the phase-field model to perform high-throughput simulations for kinetics evolution in the alloys with phase separation.