关于零件镀镍过程中针孔和麻点防止办法的探讨

On the Way to Prevent Pinholes and Pits in Parts Nickel Plating Process

镍是银白色微黄的金属,具有磁铁性,密度8.9g/cm^3,熔点1453℃。在空气中与氧作用易生成一层极薄的钝化膜,能抵抗大气、碱和一些酸的腐蚀。镍在铁上属阴极性保护镀层。孔隙率高,只有当镀层超过25um时才基本无孔。因此不单独作为防护性镀层。常用来作为中间镀层,一般采用如铜/镍/铬等形式的组合镀层来提高防护装饰性能^([1])。本文讨论了高精度零件在镀镍过程中容易出现针孔和麻点的问题,并从工艺角度较全面地阐述了镀镍过程中针孔和麻点的防治办法。

Nickel is a silvery white yellowish metal with a magnetism density of8.9g/cm3and a melting point of1453℃.A very thin layer of passive film will form when Nickel acts with oxygen in the air,which can resist the corrosion of atmosphere,alkali and some acid.Nickel is a cathodic protection coating on iron.It has high porosity.Only when the coating is more than25um,there will be basically no holes.Therefore,it is not used as a protective coating singly,but usually used as the middle coating.Generally we use such combinations as copper/nickelromium plating to improve the protective performance.This article discussed the problem of pinhole and pits easily appearing in the process of nickel plating for high-precision parts,and explained the methods of prevention and control of pinholes and pits in the process of nickel plating from the technical point of view.