Ni-Co-B合金镀层的制备及性能研究

Preparation and Properties of Ni-Co-B Alloy Coatings

为了在镀镍的基础上得到性质优良的Ni-Co-B合金镀层。通过单因素实验讨论电镀液组分和电镀工艺对合金镀层硬度的影响,筛选出对合金镀层硬度影响较大的三个因素进行正交试验。通过正交试验优化合金镀层工艺参数,经硬度值、扫描电镜、极化曲线和交流阻抗谱图的测试,对比优化前后合金镀层的性能。最终确定了Ni-Co-B合金电镀液中硫酸钴、四硼酸钠最佳质量浓度为65 g/L、4.5 g/L,J_κ为7.5 A/dm^2,所得镀层的硬度最大为689 HV,镀层表面光亮,晶粒均匀细致,镀层耐蚀性增强。

The purpose of this study is to obtain Ni-Co-B alloy coatings with good properties on the basis of the nickel hard coatings. Effects of electroplating solution component and process on the alloy coating hardness were investigated by single factor experiment. On this basis,three factors which influence the hardness of the alloy coating were selected to carry out the orthogonal test. The parameters of alloy plating process were optimized by the orthogonal experiment,and the coating performance before and after optimization was compared through the hardness value,SEM figure,polarization curves and electrochemical impedance spectroscopy. The optimum mass concentration of cobalt sulfate and sodium tetraborate in Ni-Co-B alloy plating solution were 65 g / L and 4. 5 g / L,the optimum current density was 7. 5 A / dm^2. The highest hardness of the coating could reach 689 HV,the coating surface was bright,fine and uniform and the corrosion resistance of the coating was improved.