重铬酸盐处理镁合金在航空化学品中的腐蚀行为研究  

Effect of Airplane Maintenance Materials on Corrosion Behavior of Dichromate Conversion Coating on Magnesium Alloy

作　　者：张亚博[1] 赵芯[1] 苏正良[1] 夏祖西[1] 

机构地区：[1]中国民用航空总局第二研究所,四川成都610041

出　　处：《全面腐蚀控制》2014年第5期36-40,共5页Total Corrosion Control

摘　　要：本文介绍了重铬酸盐处理后的镁合金在航空化学品中的主要腐蚀形式,使用扫描电镜和XRD表征了铬酸盐转化膜的微观结构和组成,并通过EG&G M273恒电位仪测量在航空化学品种的极化曲线和电化学阻抗谱,试验结果表明处理后的镁合金在符合AMS 1435标准的机场道面除冰防冰液、符合标准AMS1526飞机清洗剂、符合AMS 1425标准的飞机消毒液、符合AMS 1424标准的I型飞机除冰防冰液中的腐蚀电位均在-1.5^-1.6V之间,明显比裸镁合金(-2.36V)的腐蚀电位高。从电化学阻抗谱上可以看出经重铬酸盐处理后的镁合金在符合AMS 1424 I型除冰液中的腐蚀体系属于吸附型缓蚀剂体系;在符合AMS1435标准的机场道面除冰液中的腐蚀通常会产生中间产物,符合AMS 1526标准的飞机清洗剂和符合AMS 1425标准的飞机消毒液的电极反应通常受电化学极化控制。The article describes main forms of corrosion of dichromate conversion coating on magnesium alloy in airplane maintenance materials. The composition and structure of dichromate conversion coating on magnesium alloy were investigated by means of SEM and XRD. The polarization curve and electrochemical impedance spectra of dichromate conversion coating on magnesium alloy were investigated by EG ＆ G M273potentiostat. The results indicate that corrosion potential of dichromate conversion coating on magnesium alloy in Deicing/Anti-Icing Fluids of Runways and Taxiways according with AMS 1435, Cleaner according with AMS 1526, disinfectant according with AMS 1425, Type I Deicing/Anti-Icing Fluids according with AMS 1424 between -1.5V and -1.6V. The corrosion potential of dichromate conversion coating on magnesium alloy is higher than magnesium alloy. The electrochemical impedance spectroscopy indicate that dichromate conversion coating on magnesium alloy in Type I Deicing/Anti-Icing Fluids according with AMS 1424 is adsorption-type inhibitor system; the electrode reactions in Deicing/Anti-Icing Fluids of Runways and Taxiways according with AMS 1435 is generate intermediate products. The electrode reactions in Cleaner according with AMS 1526 and disinfectant according with AMS 1425 were controlled by electro-chemical polarization.

关 键 词：镁合金 航空化学品 腐蚀 重铬酸盐转化膜 

分 类 号：TG172[金属学及工艺—金属表面处理]