论文部分内容阅读
开发一种在AZ91D镁合金表面制备镁合金镁铝水滑石膜的电场辅助新工艺。该工艺可有效缩短镁铝水滑石转化膜的成膜时间。扫描电镜结果表明:短时间的电场辅助处理可在镁合金表面形成一层连续、致密的镁铝水滑石膜,但长时间处理会使膜层出现局部脱落现象。电场辅助处理2 h试样(EF1+1h)的腐蚀电流密度比镁合金基体低约2个数量级,交流阻抗测试和浸泡腐蚀试验结果均表明,该膜层能有效地保护镁合金。
A New Electric Field Auxiliary Technology for Magnesium Aluminum Hydrotalcite Films Prepared on AZ91D Magnesium Alloy Surface. The process can effectively shorten the Mg-Al hydrotalcite conversion film forming time. Scanning electron microscopy results show that a short time electric field assisted treatment can form a continuous and dense MgAl2O4 hydrotalcite film on the surface of magnesium alloy, but the long time treatment will make the film appear partial shedding phenomenon. The corrosion current density of EF1 + 1h during electric field assisted treatment was about 2 orders of magnitude lower than that of magnesium alloy. Both AC impedance test and immersion corrosion test showed that the film could effectively protect magnesium alloy.