脉冲电沉积块体纳米晶Co—Ni合金微观组织结构的研究

利用TEM、XRD、X射线能量散射谱（EDS）、位置敏感原子探针场离子显微镜(PoSAP)等方法研究了脉冲电沉积法制备的块体纳米晶Co-Ni合金的微观组织。结果表明：沉积层中Co含量随电解液中Co^2 离子浓度增加而显著增加；沉积层合金点阵参数随Co含量的增加按Vegard定律增加，同时晶粒尺寸减小；当晶粒尺寸减小到十几纳米时，出现附加的晶格膨胀效应；脉冲沉积与直流沉积相比，晶粒明显细化；PoSAP操作的在线观测和大量数据的计算机三维重构图表明，Co原子在沉积层中呈均匀分布；FIM观察分析表明纳米晶Co-Ni合金中存在三类晶间结构：正常晶界、非长程有序也非短有序的“类气态结构”和少量暗区。

STUDY ON MICROSTRUCTURE OF PULSE ELECTRO- PLATED BUCK NANOCRYSTALLINE Co-Ni ALLOY

The microstructures of nanocryatalline Co-Ni alloy produced by pulse co- electrodeposition have been studied by TEM, XRD, EDS and field ion microscopy (FIM) with po- sition sensitive atom probe(PoSAP). The results show that the Co-content in the deposits increases significantly with the increasing Co2+ concentration in electrolytes. With increasing of Co content the grain size decreased and lattice parameters increase according to Vegard law. The lattice expansion phenomenon occurs when grain size decreases to 10-20 nm. Compared to DC deposition, the deposits with finer grain size are obtained. The 3D reconstructure of PoSAP data shows that Co atoms are still uniformly distributed. FIM analyses show there are three kinds of boundary, normal boundary, gaslike disorder structure and a little dark region.