LC4铝合金在热带海洋大气环境中的早期腐蚀行为  

Initial corrosion behavior of LC4 aluminum alloy in tropical maritime environment

作　　者：李涛[1,2] 李晓刚[1] 董超芳[1] 周建龙[1] 冯佃臣[2] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]内蒙古科技大学材料与冶金学院,包头014010

出　　处：《四川大学学报（自然科学版）》2010年第6期1388-1396,共9页Journal of Sichuan University(Natural Science Edition)

基　　金：科技部国家科学基础条件平台建设项目(No.2005DKA10400)

摘　　要：通过现场暴露实验,研究了LC4铝合金在西沙群岛典型热带海洋大气环境中暴露个月和3个月后的腐蚀行为和规律.采用扫描电镜观察了腐蚀产物的表面和断面微观形貌,并用能量色散谱(EDS)、红外光谱(FTIR)和X射线光电子能谱(XPS)分析了腐蚀产物元素和组成.测试了LC4铝合金腐蚀后的极化曲线和电化学阻抗谱.实验结果表明:LC4铝合金在西沙海洋气候环境中暴露1个月和3个月后发生了明显的局部腐蚀,Cl-是促进点蚀发生的主要原因.腐蚀产物中主要包含氧、钠、铝、硅、钙、氯、硅等元素,主要腐蚀产物为Al_2O_3.3H_2OAl(OH)_3、AlOOH、AlCl_3等.随大气暴露时间延长,腐蚀电流密度减小,表明腐蚀产物对基体有一定的葆护作用.The initial corrosion laws of aluminum alloy （LC4） exposed in tropical maritime climate of Xisha Islands for 1 month and 3 months were investigated by field exposure test. The surface and crosssections morphologies of corrosion products were observed using SEM and metallurgical microscope. Energy dispersive spectrometry （EDS）, X-ray photoelectron spectroscopy （XPS） and Fourier transform infrared （FTIR） spectroscopy were used for characterizing the corrosion products formed on LC4. Furthermore, polarization curves and electrochemical impedance spectroscopy （EIS） measurement were also made on the specimens of the corroded LC4. The results showed that obvious localized attack occurred on the surface of LC4 after exposure for lmonth and 3 months. The occurrence of pitting corrosion is mainly attributed to the presence of abundant chloride ions. The corrosion products mainly consisted of elements such as O, Na, Al, Ca, Cl and Si, and the main corrosion products were made up of of Al2O3·3H2O, Al（OH）3, AlOOH and AlCl3. With the increase of time, the corrosion current density was reduced, revealing that there is some degree protective effect of the corrosion products.

关 键 词：LC4铝合金 西沙群岛 大气腐蚀 点蚀 

分 类 号：O646[理学—物理化学]