铝合金上电弧离子镀(Ti,Al)N膜的腐蚀特性

Corrosive Property of the (Ti,Al)N Coatings on Al Alloy by Arc Ion Plating

研究铝合金上电弧离子镀(Ti,Al)N膜层的腐蚀性能。通过对3种N2气分压下沉积膜层的阳极极化曲线、电化学阻抗谱、盐雾腐蚀失重曲线以及表面形貌的分析表明:沉积过程氮分压较低时,膜层中含有富金属相,耐腐蚀性能较低;增加氮分压使膜层中金属与非金属呈理想配比时,膜层的耐腐蚀性明显增加;膜层在缺陷处产生点蚀、电偶腐蚀,并通过形成裂纹、碎屑脱落使质量显著减小。

The corrosive property of （Ti,AI）N coatings on Al alloy substrate was studied. The polarization curves, electrochemical impedance, mass loss curves from salt fog corrosion and surface morphology of the deposited coatings under three different nitrogen partial pressure were analyzed. The results show that the coating contains metal-rich phase and its corrosion resistance is low under low nitrogen pressure. The corrosion resistance of the coating deposited is greatly improved under increasing nitrogen partial pressure to obtain the ideal stoichiometric composition. The pitting corrosion and pinhole corrosion occurs at the defect on coatings and the mass loss is increased due to the crack formation and chipping.