The corrosion of AA2037 aluminum alloy in alkaline aqueous solution studied using slow positron beam spectroscopy  

作　　者：Jiao-Jiao Wang Zhe-Jie Zhu Wei Yang Yi-Chu Wu Tong-Guang Zhai 

机构地区：[1]Hubei Key Laboratory of Nuclear Solid Physics, School of Physics and Technology, Wuhan University [2]Chemical and Materials Engineering Department, University of Kentucky

出　　处：《Nuclear Science and Techniques》2016年第2期6-13,共8页核技术（英文）

基　　金：supported by National Science Foundation (Nos. 11175136, 51071111, and J1210061);sponsored by the US NSF through a Grant No. DMR-1207115

摘　　要：Corrosion behavior of AA2037 T8 Al alloy in a1 M Na OH aqueous solution was investigated using slow positron beam, together with microscopy techniques and electrochemical tests. The alloy was homogenized at 510℃ for 2 h and 30 s, respectively, before final peak aging, so that one Sample A had more dispersoids than Sample B after homogenization. It was found that S parameter of the Doppler-broadened annihilation was significantly decreased near the surface in both samples in the alkaline solution. With increasing the dissolution time,Sample A showed a slower decrease rate than Sample B,which might imply that the preexistence of more dispersoids might hinder the corrosion process in Sample A.Scanning electron microscopy and atomic force microscopy observations found that the surfaces of both samples were uniformly thinned due to intense chemical dissolution by the attack of OH-. With increasing the dissolution time,Sample B was corroded more substantially and produced more and larger pits in a short dissolution time than Sample A. Furthermore, polarization curves showed that Sample A had a lower corrosion current and corrosion rate than Sample B, which revealed that the presence of the dispersoids was responsible for the better corrosion resistance in the alloy.Corrosion behavior of AA2037 T8 Al alloy in a1 M Na OH aqueous solution was investigated using slow positron beam, together with microscopy techniques and electrochemical tests. The alloy was homogenized at 510℃ for 2 h and 30 s, respectively, before final peak aging, so that one Sample A had more dispersoids than Sample B after homogenization. It was found that S parameter of the Doppler-broadened annihilation was significantly decreased near the surface in both samples in the alkaline solution. With increasing the dissolution time,Sample A showed a slower decrease rate than Sample B,which might imply that the preexistence of more dispersoids might hinder the corrosion process in Sample A.Scanning electron microscopy and atomic force microscopy observations found that the surfaces of both samples were uniformly thinned due to intense chemical dissolution by the attack of OH-. With increasing the dissolution time,Sample B was corroded more substantially and produced more and larger pits in a short dissolution time than Sample A. Furthermore, polarization curves showed that Sample A had a lower corrosion current and corrosion rate than Sample B, which revealed that the presence of the dispersoids was responsible for the better corrosion resistance in the alloy.

关 键 词：慢正电子束 碱性水溶液 腐蚀行为 铝合金 扫描电子显微镜 光谱 溶解时间 电化学测试 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG172[金属学及工艺—金属材料]