铝合金Ce-Mn转化膜的制备工艺研究

摘要

以硝酸铈和高锰酸钾为主盐,以氟化钠为促进剂,在铝合金表面制备Ce-Mn转化膜.通过正交试验确定最佳的钝化工艺条件为:硝酸铈8 g/L,高锰酸钾2 g/L,氟化钠0.06 g/L,pH值2.0,70℃,10 min.最佳工艺条件下制备的Ce-Mn转化膜呈金黄色,表面均匀,耐蚀性较好.Ce-Mn转化膜的耐蚀性接近六价铬转化膜的耐蚀性.%Ce-Mn convertion coating was prepared on the surface of aluminum alloy taking Ce(NO3)2 and KMnO4 as main salt and NaF as acceleration agent.The optimum process conditions of passivation determined through orthogonal experiment were as follows:Ce(NO3)3 8 g/L,KMnO4 2 g/L,NaF 0.06 g/L,pH value 2.0,temperature 70 ℃,time 10 min.Using optimum passivation solution formula and under optimum process conditions,the prepared Ce-Mn convertion coating showing golden,its surface was uniform and corrosion resistance was better.The corrosion resistance of Ce-Mn convertion coating approached that of hexavalent chromium conversion coating.