室温下,在AZ91 镁合金表面制备Ce-Mn 复合转化膜,通过单因素实验研究了Ce(NO3 )3 浓度和KMnO4 浓度对转化膜耐腐蚀性能的影响,确定了较佳的浓度配比。分析了转化膜的结构及组成,通过交流阻抗谱,研究了Ce-Mn 对基体镁合金的防护机制。结果表明:Ce-Mn 转化膜为非晶态物相结构,膜层主要由铈、锰和少量镁的氧化物或氢氧化物组成,Ce-Mn 转化膜可对镁合金起到较好的防护作用。

Ce-Mn chemical conversion coating was prepared on AZ91 magnesium alloy at room temperature. The effects of Ce(NO3 )3 and KMnO4 concentrations on the corrosion resistance of conversion coating were investigated by the single factor experiment and the optimum concentrations were obtained. The conversion coating structures and compositions were studied. The anti-corrosion mechanism of Ce-Mn coating on magnesium alloy was investigated through electrochemical impedance spectroscopy (EIS). The results show that Ce-Mn conversion coating is mainly composed of oxide or hydroxide of Ce, Mn and little Mg with amorphous structure. The Ce-Mn conversion coating can play better anti-corrosion to magnesium alloy.