辐照条件下Zr-Nb二元合金的相图计算

Phase Diagram Calculation of Zr-Nb Binary Alloy Under Irradiation

通过考虑辐照引起的弹道混合效应,应用热力学模型和辐照条件下的有效自由能模型,研究了辐照诱发产生的缺陷对Zr-Nb二元合金相稳定性的影响.基于Zr-Nb二元合金的扩散参数和已优化的热力学参数,计算了不同辐照条件下Zr-Nb二元合金的稳态相图.计算结果表明,Zr-Nb二元合金的稳态相图与热力学平衡相图在低温下存在显著的差异:在辐照条件下,原本在高温时稳定存在的(βZr,Nb)相延伸至低温区域,同时出现了一个低温包析反应(Nb)+(αZr)(βZr,Nb),包析反应的温度随着辐照强度的增大而升高,从而使得(βZr,Nb)相的范围也随之增大.

By taking into account the ballistic mixing effect caused by irradiation,a model describing effective free energy for alloys under irradiation was used to study the influence of irradiation-induced defect on phase stability in the Zr-Nb binary alloy.Based on the effective free energy model and the thermodynamic model,the phase diagrams of Zr-Nb binary alloys under different irradiation intensities were calculated and the difference between the calculated phase diagram and the conventional thermodynamic equilibrium phase diagram was discussed.The obtained results showed that,under irradiation,the high-temperature stable(βZr,Nb)phase was stabilized,resulting in a peritectoid reaction(Nb)+(αZr)(βZr,Nb)at a lower temperature.With the increase of the irradiation intensity,the temperature of the peritectoid reaction increased,and the phase region of the(βZr,Nb)phase also increased.