铁镍合金中硼原子-空位复合体扩散系数的计算

Calculation of Diffusion Coefficients of Boron Atom-Vacancy Complexes in Fe-40%Ni Alloy

提出一种计算溶质原子-空位复合体扩散系数的方法。该方法通过分析晶界偏聚过程中溶质原子-空位复合体的扩散机制,建立溶质原子-空位复合体变温扩散方程,以实验测定的连续冷却过程偏聚阶段溶质贫化区宽度为已知条件,数值求解溶质原子-空位复合体扩散系数。将此方法应用于含硼1×10-5%(质量分数)Fe-40%Ni-B合金体系,得到硼原子-空位复合体扩散系数为8.0×10-7exp(-1.28/kT)(m2.s-1)。

A calculation method of the diffusion coefficients of solute atom-vacancy complexes was developed. Based on the complexes diffusion mechanism of solute grain boundary segregation, the diffusion equations of the complexes were built and resolved numerically in a continuously cooling process. The diffusion coefficient of boron atom-vacancy complexes in Fe- 40%Ni alloy doped with 1.0 × 10^-5% boron was obtained by comparing the calculated width of solute depletion zone with the experimental data： 8.0 × 10^-7 exp（-1.28/kT） （m^2·s^-1）.