Phase-Field Simulation of Ni-Al-Cr System with Chemical Free Energy Using CALPHAD Method

Abstract

  The size, morphology and dispersion of γ′ precipitates affect the creep behaviors of Ni-base single-crystal superalloys. Phase-field modeling is powerful tool to predict such microstructure evolution. In this research, the Gibbs-free-energy function of γ and γ′ phases in the ternary Ni-Al-Cr system with a four-sublattice model was introduced to extend the phase-filed simulation of γ/γ′-microstructure-evolution to the ternary system. The values of γ/γ′-phase-compositions were in good agreements with the estimation of Dupin's CALPHAD method.