NiCl2 含量对电沉积 Ni-纳米 TiN 复合镀层过程的影响

目的针对氨基磺酸镍体系镀镍液,优化活化剂NiCl2的用量,提高Ni-纳米TiN复合镀层的性能。方法采用超声-脉冲电沉积工艺制备Ni-纳米Ti N复合镀层,研究NiCl2含量对镀液的电导率及复合镀层的厚度、显微硬度、表面微观形貌等的影响。结果镀液的电导率及复合镀层的厚度、显微硬度均随NiCl2含量的增加呈现先增大、后减小的变化趋势。当NiCl2的用量为30 g/L时,镀液的导电性能最佳,电导率值为61.3 m S/cm,复合镀层的厚度及显微硬度均达到最大值,分别为84μm和760HV,并且复合镀层表面平整光滑,晶粒尺寸最小。结论 NiCl2含量对镀液及复合镀层的性能有很大影响,适量的NiCl2可以防止阳极钝化,提高镀液的导电能力及沉积速率,使复合镀层的厚度增加,显微硬度提高,晶粒细化,微观形貌获得改善,性能提高。适宜的NiCl2用量为30 g/L。

Influences of NiCl2 Content on Electrodeposited Ni-Nano TiN Composite Coating Process

Objective To optimize the nickel chloride content, and improve the performance of Ni-nano TiN composite coatings for nickel sulfamate system electrolyte. Methods The effects of different nickel chloride content on the plating solution conductivity and the thickness, microhardness, surface microstructure of Ni-nano TiN composite coating prepared by ultrasonic-electrodepositing method were studied. Results The plating solution conductivity and the thickness, microhardness of the composite coating increased firstly and decreased afterwards with the increase of nickel chloride content. When the content of nickel chloride was 30 g/L, the bath conductivity was the best and the plating solution conductivity value was 61. 3 mS/cm, the thickness of the composite coating reached the maximum value of 84 μm, the microhardness reached the maximum value of 760HV, at the same time, the composite coating surface was smooth and the grain size was minimal. Conclusion Nickel chloride content had a great influence on the per-formance of the plating solution and the composite coating. A suitable content of nickel chloride could prevent anodic passivation, increase the conductive ability of the plating solution, the deposition rate, and the thickness, microhardness of composite coating, refine the grains, and improve the microstructure and performance of Ni-nano TiN composite coating. The suitable content of nickel chloride was 30 g/L.