Ni-Sn-P合金镀层在人工海水中的腐蚀行为及腐蚀机理

利用扫描电子显微镜(SEM)和能谱(EDS)测试了电镀Ni-Sn-P合金镀层在人工海水中腐蚀前后表面形貌和合金成分的变化,结合X射线光电子能谱(XPS)对腐蚀后合金表面的组成进行了分析,并在此基础上探讨了Ni-Sn-P合金镀层在人工海水中的腐蚀机理。研究结果表明:电镀Ni-Sn-P合金在人工海水中耐蚀性优于Ni-P合金,由于人工海水中的氯离子的穿透效应而出现的局部腐蚀孔数较Ni-P合金大幅减少,腐蚀后Ni-Sn-P合金表面形成由SnO₂、SnCl₄、Ni₃(PO₄)₂、NiO和Ni(OH)₂组成的膜层,对合金耐蚀性的提高起到重要作用。

Corrosion behavior and mechanism of Ni-Sn-P alloy coatings in artificial sea water

The changes of microscopic morphology and elemental composition of Ni-Sn-P alloy coatings before and after corrosion in artificial sea water were studied with scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS), and the corrosion products were examined with X-ray photoelectron spectroscopy (XPS).The corrosion mechanism of Ni-Sn-P alloy coatings in artificial sea water is discussed.EIS spectra and SEM showed that the corrosion resistance of electroplating Ni-Sn-P alloy in artificial seawater was better than Ni-P alloy, and the number of localized corrosion hole caused by penetration effect of Cl^- was greatly reduced.After corrosion a layer of passive film composed of SnO₂, SnCl₄, Ni₃(PO₄)₂, NiO and Ni(OH)₂ was formed on the surface of Ni-Sn-P alloy, which played an important role in improving Ni-Sn-P alloy coatings corrosion resistance.