Calculation of steady-state dynamical phase diagram in U-Mo binary system under irradiation

Abstract

The steady-state dynamical phase diagram of U-Mo system under irradiation is studied by the thermodynamic model and effective free energy model. In the effective free energy model, we consider the irradiation-enhanced diffusion and ballistic mixing caused by recoil implantation and cascade collision. The effective free energy and diffusivity of each phase in U-Mo binary system at different temperatures were calculated. The dynamical phase diagrams of U-Mo alloys under different irradiation intensities were calculated and the differences between the dynamical phase diagram and thermodynamic equilibrium phase diagram was discussed. The calculated results show that, due to the irradiation-induced ballistic mixing, the high-temperature stable γ(U,Mo) phase can be stabilized near room temperature, which agree well with the experimental reports.