纯铜表面纳米化对镍扩散的影响

Effects of surface nanocrystallization on diffusion of nickel

利用表面机械研磨处理(SMAT)在纯铜表面制备出纳米结构表层,并对其表面进行了电镀镍处理,采用扫描电子显微镜分析了镍原子在纳米晶铜中的扩散行为。结果表明:表面纳米晶层内存在有大量非平衡态缺陷和晶界,尤其是三叉晶界数量增加,降低了镍原子扩散的激活能,提高了其扩散系数,从而加快了镍原子的扩散。

Nanostructured surface layer was synthesized on pure copper by using surface mechanical attrition treatment （SMAT）. The copper samples surface was cleaned and electroplated with a layer of pure nickel and scanning electron microscope （SEM）is used to analyze diffusion behavior of Ni atoms in the pure copper. Experimental results show that the increase of diffusion rate of Ni atoms is attributed to lower diffusion activation energy and higher diffusion coefficient, which induced by the non-equilibrium defects and grain boundary in nanocrystalline, especially, a large number of triple junction boundaries.