喷射电沉积Co-Ni纳米合金沉积层的组织和性能

用高速喷射电沉积法快速制备了块体纳米晶Co-Ni合金,研究了喷镀工艺参数(主盐浓度、电解液喷射速度和电流密度等)对沉积层成分、微观组织结构及性能的影响.结果表明:提高喷射电沉积电解液的搅拌强度能有效减小扩散层的厚度,使电沉积在较高的极限电流密度下进行,提高沉积速度.极限电流密度的增大使阴极过电位增大,从而提高合金的形核速率,使沉积层晶粒的尺寸减小、显微硬度升高.随着电解液中Co2 含量的增加,沉积层中Co含量增加,导致沉积层相结构由单相α-Co(Ni)转变为α-Co(Ni)和ε-Co(Ni)双相组织,并使表面的形貌发生明显的变化.

Microstructure and property of nanocrystalline Co--Ni alloy prepared by jet electrodeposition

The influence of amount of CoSO$_{4}cdot$6H$_{2}$O in electrolyte on chemical composition,microstructure and property of nanocrystalline Co--Ni alloy deposit layersprepared by jet electrodeposition was investigated. The results show that withthe increase of stirring intensity of the electrolyte, the thickness of diffusedlayer decreases, the critical current density increases, and then the depositingrates increase. At the same time, the increase of over--potential results in thenucleating rate and the micro--hardness of deposits increasing, while the grainsize deposits decreasing. Co content in deposits increases with increasing theCo$^{2+}$ content in electrolyte, which results in the change of the microstructuresin deposit layers from face--centered cubic $alpha$--Co(Ni) to mixture offace--centered cubic $alpha$--Co(Ni) and hexagonal close--packed$varepsilon$--Co(Ni), and the change of morphology of surface of deposit layers.