Atomic-based phase-field method for the modeling of radiation induced segregation in Fe–Cr

• Published in: Computational materials science Vol. 122; pp. 249 - 262
• Main Authors: Piochaud, J.B., Nastar, M., Soisson, F., Thuinet, L., Legris, A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2016; Elsevier
• Subjects: Computer simulation; Diffusion; Evolution; Intermetallic compounds; Iron–chromium alloys; Mathematical models; Monte Carlo methods; Monte Carlo simulations; Nuclear Experiment; Nuclear Theory; Phase-field model; Physics; Point defects; Radiation induced segregation; Segregations; Transport; Iron–chromium alloys; Radiation induced segregation; Phase-field model; Monte Carlo simulations
• ISSN: 0927-0256; 1879-0801
• DOI: 10.1016/j.commatsci.2016.05.021

[Display omitted] We present a quantitative phase-field modeling of radiation-induced segregation in Fe–Cr alloys. The evolution of chemical and point defect concentration fields are described by an Onsager formalism combined to a Cahn–Hilliard like diffusion equation for the introduction of non-uniform driving forces. Both the Onsager transport coefficients and the driving force parameters are extracted from atomic Monte Carlo simulations with point defect diffusion models fitted on DFT calculations, in a composition range between 0 and 20at.% Cr and in a temperature range between 600 and 1000K. Phase-field simulations are able to quantitatively reproduce the evolution of segregation profiles obtained from direct atomistic kinetic Monte Carlo simulations, while being typically two orders of magnitude faster. It is shown that a precise parameterization of the concentration-dependent Onsager transport coefficients, thermodynamic factors, and equilibrium point defect concentrations is crucial for the phase-field method to be quantitative.