(1. 中国科学院金属研究所 环境腐蚀中心，沈阳 110016；
2. 东北大学 材料与冶金学院，沈阳 110016)
摘 要:
关键字: 钙离子；镁合金；锰系磷酸盐转化膜；裂纹
（1. Environment Corrosion Center, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China;
2. School of Material and Metallurgy, Northeast University, Shenyang 110016, China）
Abstract:Ca2+ was added into the phosphate conversion solution of magnesium alloy as an additive. Roughness tester and electrochemical test were used to analyze the effect of Ca2+ on the roughness and corrosion resistance of coating; SEM was used to observe effect of Ca2+ on the morphology of coating. XPS was used to investigate the composition of coating and what kind of Ca salts existing in the coating. The results show that the surface of coating turns to smooth and the crack of the coating becomes narrow when the concentration of Ca(NO3)2 in conversion solution exceeds 2 g/L. The corrosion resistance of coating is the best at 5 g/L of Ca(NO3)2. XPS results show that the coating is composed of Mn, P, O, Mg, Ca and Al, and Ca2+ exists in the coating in the form of CaCO3, CaO and a kind of amorphous calcium phosphate salt.
Key words: Ca2+; magnesium alloy; phosphate conversion solution; crack
