脉冲镀镍工艺及镀层性能研究

Research on Pulse Electroplating Process of Ni Coating

采用脉冲电镀方法在紫铜片表面制备均匀光亮光滑的镍镀层.借助扫描电子显微镜（SEM）进行分析,并对其镀层结合力、孔隙率、耐磨性等测试考察镀层性能和结构.为获取最适宜的工艺参数,研究脉冲温度、平均电流密度、占空比对镍镀层显微硬度的影响.通过磨损失重测试,脉冲电镀镍镀层的耐磨性能远远高于直流镍镀层.最佳工艺条件为：硫酸镍300 g/L、氯化镍50 g/L、硼酸40 g/L、平均电流密度为3 A/dm2、占空比为50％、镀液温度为40～60℃.结果表明：在适宜的脉冲条件下,镀层结构能够得到进一步的细化,从而获得致密、平整、均匀、光亮的镀层,且镀层与铜基体结合良好.

A uniform, smooth and bright Ni coating was prepared on copper by pulse electroplating. The performance and structure of Ni coating were investigated via SEM, coating adhesion, porosity, and wear resistance test. The influence of the hardness of Ni coating such as bath temperature, average current density, and duty cycle was studied, getting the most suitable parameters. Through weight loss test, the pulse was much higher than the wear resistance of Ni coating current. We determined the following optimum conditions for Ni coating ：NiSO4 300 g/L,NiCl2 50 g/L,H3BO3 40 g/L,average current density of 3 A/ dm2, duty cycle of 50 %, bath temperature of 40- 60 ℃. The results showed that the structure of coating could be further refined to obtain a dense, smooth, uniform, bright coating, and the copper substrate was coated with a good combination under the optimum pulse conditions.