放电等离子烧结电场下Ni-Al体系FCC相的扩散行为  

Diffusion behavior of FCC Ni-Al system in spark plasma sintering electric field

作　　者：王飞 刘钰玲 都昌发 闵倩辉 刘辉新 文诗艺 杜勇[1] WANG Fei;LIU Yuling;DU Changfa;MIN Qianhui;LIU Huixin;WEN Shiyi;DU Yong(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;School of Mathematics and Statistics,Central South University,Changsha 410083,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083 [2]中南大学数学与统计学院,长沙410083

出　　处：《粉末冶金材料科学与工程》2021年第5期412-418,共7页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金资助项目(51671219)。

摘　　要：采用熔炼法制备Ni-9Al(摩尔分数,%)合金和纯Ni,然后组成Ni/Ni-Al/Ni FCC单相扩散偶在放电等离子烧结炉中进行扩散退火,结合电子探针显微分析(electronic probe micro analysis,EPMA),得到Ni-Al体系FCC相在1 173~1 373 K时SPS电流作用下扩散后的成分距离曲线(即Al含量分布曲线),并采用Sauer-Freise方法与经验公式计算扩散系数,同时基于无外场影响下的原子移动性参数模拟无电流作用的成分距离曲线并计算扩散系数。将模拟的成分距离曲线与实验得到的成分距离曲线进行对比。结果表明,电流对Ni-Al合金原子扩散存在促进作用。电流方向对Ni-Al合金扩散无明显影响,不同电流方向下的成分距离曲线与扩散系数重合度高,故电迁移对Ni-Al合金扩散的影响可忽略。施加电流对扩散频率因子影响不大,但使扩散激活能明显降低。The smelting method was employed to prepare the Ni-9 Al(mole fraction, %) alloys and pure Ni, and then the Ni/Ni-Al/Ni diffusion couples were annealed for diffusion in spark plasma sintering(SPS). The concentration profiles of FCC Ni-Al system at 1 173-1 373 K under the effect of SPS current were obtained combining with electronic probe microanalysis(EPMA). The Sauer-Freise method and empirical formula were employed to calculated diffusion coefficients respectively. The concentration profiles without current were simulated based on the atomic mobilitiy parameters without the influence of applied field and then the diffusion coefficients were calculated meanwhile.Comparing the simulated concentration profiles with the experimental ones. The results show that the current promotes the diffusion of Ni-Al alloys. The direction of the current has negligible effect on the diffusion of Ni-Al alloys. The concentration profiles and diffusion coefficients under different current directions have a high degree of overlap,indicating that the influence of electromigration on the diffusion of Ni-Al alloy is negligible. The applied current has little effect on the diffusion frequency factor, while the applied current significantly reduces the diffusion activation energy.

关 键 词：SPS 扩散偶 NI-AL 扩散系数 原子移动性参数 电迁移 

分 类 号：TG113.12[金属学及工艺—物理冶金]