Microstructure and property of nanocrystalline Co--Ni alloy prepared by jet electrodeposition
喷射电沉积Co-Ni纳米合金沉积层的组织和性能

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