《厦门大学学报（自然科学版）》

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.

引言
1 有效自由能模型
2 结果与讨论
3 结论

表1 本研究中所使用的扩散参数<br/>Tab.1 Diffusion data used in this study

表1 本研究中所使用的扩散参数
Tab.1 Diffusion data used in this study

图1 (αZr)相和(βZr,Nb)相中空位的平衡浓度在不同原子离位率与位错密度下随温度的变化<br/>Fig.1 Vacancy equilibrium concentrations of(αZr)phase and(βZr,Nb)phase as a function of temperature for various combinations of displacement rates and dislocation densities{Kis=4πrisDi,

图1 (αZr)相和(βZr,Nb)相中空位的平衡浓度在不同原子离位率与位错密度下随温度的变化
Fig.1 Vacancy equilibrium concentrations of(αZr)phase and(βZr,Nb)phase as a function of temperature for various combinations of displacement rates and dislocation densities{Kis=4πrisDi,

图2 (αZr)相和(βZr,Nb)相中Nb原子的自扩散系数在不同原子离位率与位错密度下随温度的变化<br/>Fig.2 Self-diffusion coefficients of atoms Nb in the(αZr)phase and(βZr,Nb)phase as a function of temperature at a series of displacement rates and dislocation densities

图2 (αZr)相和(βZr,Nb)相中Nb原子的自扩散系数在不同原子离位率与位错密度下随温度的变化
Fig.2 Self-diffusion coefficients of atoms Nb in the(αZr)phase and(βZr,Nb)phase as a function of temperature at a series of displacement rates and dislocation densities

图3 不同位错密度下(βZr,Nb)相的有效自由能<br/>Fig.3 Effective free energy of the(βZr,Nb)phase with different dislocation densities

图3 不同位错密度下(βZr,Nb)相的有效自由能
Fig.3 Effective free energy of the(βZr,Nb)phase with different dislocation densities

图4 计算的(βZr,Nb)相的有效自由能随温度(a)、原子离位率(b)和原子置换数(c)的变化<br/>Fig.4 Calculated effective free energy of the(βZr,Nb)phase with different temperatures(a),displacement rates(b)and atomic displacement numbers(c)

图4 计算的(βZr,Nb)相的有效自由能随温度(a)、原子离位率(b)和原子置换数(c)的变化
Fig.4 Calculated effective free energy of the(βZr,Nb)phase with different temperatures(a),displacement rates(b)and atomic displacement numbers(c)

图5 不同原子离位率下(βZr,Nb)相的溶解度间隙<br/>Fig.5 Miscibility gap of the(βZr,Nb)phase under different displacement rates

图5 不同原子离位率下(βZr,Nb)相的溶解度间隙
Fig.5 Miscibility gap of the(βZr,Nb)phase under different displacement rates

图6 Zr-Nb二元合金的热力学平衡相图与辐照条件(K0=10-4dpa/s,ηrepl=100 dpa-1)下稳态相图的比较<br/>Fig.6 Comparison between the thermodynamic equilibrium phase diagram and the steady-state phase diagram of theZr-Nb binary alloy under K0=10-4dpa/s and ηrepl=100 dpa-1

图6 Zr-Nb二元合金的热力学平衡相图与辐照条件(K0=10-4dpa/s,ηrepl=100 dpa-1)下稳态相图的比较
Fig.6 Comparison between the thermodynamic equilibrium phase diagram and the steady-state phase diagram of theZr-Nb binary alloy under K0=10-4dpa/s and ηrepl=100 dpa-1

表2 Zr-Nb二元合金中的不变系反应<br/>Tab.2 The invariant reactions in the Zr-Nb binary alloy

表2 Zr-Nb二元合金中的不变系反应
Tab.2 The invariant reactions in the Zr-Nb binary alloy

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备注

引言

1 有效自由能模型

2 结果与讨论

3 结论

学报简介

备注

引言

1 有效自由能模型

2 结果与讨论

3 结 论

学报简介

3 结论