Ti-Sn和Ti-Ni二元系中bcc相互扩散系数的实验测定及动力学计算

Measurement of Interdiffusivities and Calculation of Kinetics in bcc Ti-Sn and Ti-Ni Binary Systems

通过制备Ti/Ti-7%Sn、Ti/Ti-9%Sn和Ti/Ti-6%Ni扩散偶(7%,9%,6%均为原子分数),利用EPMA(electron probe micro-analyzer)技术测定了扩散偶的摩尔分数-距离曲线,根据摩尔分数-距离曲线用Den Broeder方法计算了TiSn和Ti-Ni二元系中bcc相在1 273,1 373和1 473K下的互扩散系数.利用DICTRA(diffusion controlled transformation)软件分别优化了Ti-Sn和Ti-Ni二元系中bcc相的扩散迁移率参数,计算结果和实验数据取得了良好的一致性.运用优化得到的扩散迁移率参数计算了扩散偶的摩尔分数-距离曲线,通过计算结果和实验数据比较表明,所优化的扩散迁移率参数具有良好的准确性与有效性.

On the basis of Ti/Ti-7 % Sn, Ti/Ti-9 % Sn and Ti/Ti-6 % Ni diffusion couples （7 %, 9 %, 60%were atomic fraction）, respec- tively,interdiffusion coefficients in the bcc Ti-Sn and Ti-Ni binary alloys at the temperature of 1 273,1 373 and 1 473 K were evalua- ted by means of the Den Broeder method and electron probe micro-analyzer （EMPA）.Based on various reported experimental diffu- sion coefficients and what was measured in this study,accurate atomic mobilities in the bcc Ti-Sn and Ti-Ni alloys were assessed via the diffusion controlled transformation （DICTRA） simulation package. Comparison between the calculated and measured diffusion coefficients indicated that most of the experimental information can be reproduced reasonably.The developed diffusion mobilities were further validated by the prediction of the mole fraction-distance profiles.