水合肼体系化学镀镍时间对钕铁硼电镀/化学镀镍层耐蚀性的影响

Effect of electroless plating time in a bath with hydrazine hydrate as reductant on corrosion resistance of electroplated/electroless plated bilayered nickel coating on neodymium-iron-boron permanent magnet

以钕铁硼永磁体为基体,先采用瓦特体系镀液电镀镍,再采用以水合肼为还原剂的镀液化学镀镍,总施镀时间为4 h。分别采用金相显微镜、扫描电镜、能谱仪、中性盐雾试验和电化学测试研究了化学镀镍时间对镀镍层厚度、微观形貌、元素组成和耐蚀性的影响。结果表明,随化学镀镍时间延长,镀镍层的厚度维持在10μm左右,致密性、均匀性和耐蚀性都有改善。

Nickel electroplating was conducted on NdFeB permanent magnet in a Watt’s bath followed by electroless nickel plating in a bath using hydrazine hydrate as reluctant,and the total time was 4 h.The effect of electroless nickel plating time on the thickness,micromorphology,elemental composition,and corrosion resistance of nickel coating was studied by metallography,scanning electron microscopy,energy-dispersive spectrometry,neutral salt spray testing,and electrochemical measurement.The results showed that the thickness of nickel coating kept at ca.10μm with the extending of electroless nickel plating time,and its compactness,uniformity,and corrosion resistance were improved.