A new phase-field method for simulating γ′ precipitation in multicomponent nickel-base superalloys

The phase-field method is used to develop a new technique to simulate gamma' precipitation in multicomponent Ni-base superalloys. This technique generates the Gibbs free energy for both the gamma and gamma' phases from the single function formalism of both phases in the CALPHAD method Without using conventional CALPHAD software. The Gibbs free energy surfaces for eight- element multicomponent systems are used to confirm that there is an accurate coupling with the CALPHAD method. because they compare favorably with calculated results from Thermo-Calc. In addition, gamma' precipitation in a third-generation Ni-base superalloy containing eight components is simulated in one dimension with anti-phase effects of the gamma' phase on the precipitate interactions, The simulation results reveal late-stage enrichments of Re and W in the gamma phase during coalescence of the gamma' precipitates. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.