铝合金稀土磷化与铬磷化比较

采用电化学测试、全浸腐蚀试验和结合力测试,研究了6061铝合金铬磷化处理和以稀土为添加剂的磷酸盐处理所形成的化学转化膜的工艺性能。动力学研究表明,两者的成膜过程是不相同的。极化曲线测试结果显示,在弱极化区范围内,两者抗蚀性能相近,而在强极化区,铬磷化转化膜的抗蚀性优于以稀土为添加剂的磷酸盐化学处理所形成的转化膜,全浸腐蚀试验有类似的结果。结合力测试结果则表明,以稀土为添加剂的磷酸盐化学处理所形成的转化膜与有机涂层间的结合力要优于铬磷化转化膜。

Comparison of Rare Earth Phosphating and Chromate Phosphating on Aluminum Alloy

The performance of the chemical conversion coatings formed on 6061-aluminum alloy with chromate phosphate process and phosphate process with rare earth as additive was studied by electrochemical measurement,immersing corrosion test and adhesion test.The results showed that the film forming processes were different.In the weak polarized scope,both of the corrosion resistance were close,but in the strong polarized scope,the corrosion resistance of the films formed by chromate phosphate process was better than that by phosphate process with rare earth as additive.Adhesion force between the conversion coating formed by phosphate process with rare earth as additive and the organic coating surpassed that of chromate phosphate process.