空位扩散诱导点缺陷环与富Cu相的相互作用

Phase field study on the interaction between vacancy diffusion induced point defects and Cu-rich phase

摘要:

辐照诱导产生的点缺陷会加速核电站材料微观组织的演变,在很大程度上影响反应堆的寿命。本文基于相场法的四元连续相场模型,耦合了空位和间隙原子,利用该模型模拟了Fe-15at.%Cu-1at.%Ni-1at.%Mn合金在空位扩散机制下的相分离,研究了点缺陷与富Cu相的相互作用机理。结果表明,空位和间隙原子会促进富Cu相的长大和粗化,点缺陷初始浓度的升高会促进相分离,加快析出相的失稳分解速率,并且升高温度会延缓Cu原子和空位环的生长和粗化,点缺陷也可以增加一定的屈服强度,为探究空位扩散机制影响抗辐照材料性能方面提供了新的思路。

Abstract:

Irradiation-induced generation of point defects accelerates the evolution of the microstructure of nuclear power plant materials and affects the reactor lifetime to a large extent. In this paper, based on the quadratic continuous phase field model of the phase field method with coupled vacancy and interstitial atoms, the phase separation of Fe-15at.%Cu-1at.%Ni-1at.%Mn alloy under the vacancy diffusion mechanism is simulated using this model, and the interaction mechanism between the vacancy diffusion-induced point defects and the Cu-rich phase is investigated. The results show that the presence of vacancy and interstitial atoms promotes the growth and coarsening of the Cu-rich phase, the increase of the initial concentration of point defects promotes the phase separation and accelerates the nucleation rate of the precipitated phase, and the elevated temperature delays the growth and coarsening of Cu atoms and vacancy rings, and the point defects can also increase the yield strength to a certain extent, which provides a new idea to investigate the effect of vacancy diffusion mechanism on the properties of irradiation-resistant materials.