镍–碳化钨复合电镀工艺优化及镀层耐蚀性

Optimization of nickel–tungsten carbide composite plating process and corrosion resistance of coating

采用复合电镀工艺在铜表面制备了耐蚀性优良的Ni–WC复合镀层。通过正交试验对工艺条件进行优化,得到的最佳配方和工艺为:NiSO_4·6H_2O 250~300 g/L,NiCl_2·6H_2O 40~50 g/L,WC微粒35 g/L,H_3BO_3 35~40 g/L,十二烷基硫酸钠0.05 g/L,电流密度3 A/dm^2,温度40°C,磁力搅拌,时间4 h。最佳工艺条件下,所得Ni–WC复合镀层的WC质量分数为29.95%,厚度为103.0μm,中性盐雾试验中出现红锈的时间为120 h,耐蚀性远优于纯Ni镀层(耐红锈时间96 h)。

Ni-WC composite coating with excellent corrosion resistance was obtained on the surface of copper substrate by composite electroplating. The optimal bath composition and process conditions obtained by orthogonal test are as follows： NiSO4·6H2O 250-300 g/L, NiCl2·6H2O 40-50 g/L, WC particles 35 g/L, H3BO3 35-40 g/L, sodium dodecyl sulfate 0.05 g/L, current density 3 A/dm2, temperature 40℃, magnetic stirring, and plating time 4 h. The Ni-WC composite coating obtained under the optimal conditions contains 29.95wt% WC and has a thickness of 103.0 μm. There is no red rust on the Ni-WC composite coating surface until 120 h of neutral salt spray test, showing a much better corrosion resistance than the pure Ni coating which endures only 96 h for red rust in NSS test.