电沉积方式对纳米晶钴镀层的结构和摩擦学性能影响研究

采用不同电沉积方式制备了不同结构和晶粒尺寸的纳米晶钴(Co)镀层.采用扫描电镜和X-射线衍射仪分别分析了镀层表面形貌、晶相结构与晶粒尺寸.采用MV-2T显微硬度计测试镀层的硬度.最后采用UMT-3M多功能摩擦磨损试验机对镀层的摩擦和磨损性能进行了评价,并用扫描电镜对其磨损表面进行了观察分析.结果表明:电沉积方式对制备的纳米Co镀层的晶相结构、晶粒尺寸、镀层形貌和摩擦磨损性能影响显著;采用双脉冲制备的纳米Co镀层具有最小的晶粒尺寸、最高的硬度及较好的耐磨性能;采用单双脉冲混合电镀制备的纳米Co镀层表面针孔孔洞直径最小,结构最致密,耐磨性能最好.这些研究结果说明可通过优化电沉积方式来提高镀层的结构致密性,改善其硬度和耐磨性能.

Influence of Electro-Deposition Methods on the Structure and Tribological Properties of Nanocrystalline Cobalt Deposit

The nanocrystalline cobalt deposit with different structural characteristics and grain size were prepared by using different electro-deposition methods. The surface topography, and the size and the crystalline phase of the cobalt deposit were investigated by scanning elecrtron microscopy (SEM) and X-ray diffraction (XRD), respectively. The microhardness of the cobalt deposit was evaluated on MV-2T hardness tester. The friction and wear properties of the cobalt deposit were studied on a UMT-3M multifunctional friction and wear tester, and their worn surface were characterized by SEM. The results show that the size and crystalline phase of cobalt deposit, tribological properties and microhardness, were significantly affected by the electro-deposition methods. The cobalt deposit prepared by dual pulse electro-deposition had the smallest grain size, the highest microhardness and better wear resistance. The pin holes of the nanocrystalline cobalt deposit prepared by single-double pulse electro-deposition were the smallest. And this cobalt deposit also exhibited the best wear resistance and higher microhardness. These results indicate that the structure, anti-wear properties and microhardness of cobalt deposit can be controlled by controlling electro-deposition methods.