Abstract:

Ni-P and its nano-CeO₂ doped coating were electrolessly prepared in acidic condition，and their microstructure and anti-corrosion property were studied and compared.Scanning electronic microscopy（SEM），transmission electronic microscopy（TEM），X-ray diffraction spectrometer（XRD）and differential scanning calorimeter（DSC）were used to examine surface morphology and microstructure of coatings.The results showed that Ni-P coating had partial amorphous structure mixed with nano-crystals，while the Ni-P/CeO₂ coating had perfect amorphous structure.Upon heating，Ni₃P precipitation and Ni crystallization took place in both coatings but at different temperatures of phase change.In addition，the Ni-P/CeO₂ coating had sintered phase of NiCe₂O₄ spinels.The anti-corrosion property and passivity were improved in the CeO₂-doped coating because it was less liable to undergo localized corrosion and had a slower corroding rate than its CeO₂-free counterpart.During the co-deposition process，some Ceⁿ⁺（n=3，4）ions might be adsorbed to the metal/solution electrical double layer and hinder nickel deposition.Ni-P/CeO₂ coating’s perfect amorphous structure was probably due to the hindered crystal-typed deposition of nickel and the promoted deposition of phosphorous.

Key words:

搀杂, 化学镀, Ni-P, 稀土元素, 腐蚀

关键词:

搀杂, 化学镀, Ni-P, 稀土元素, 腐蚀