摘要
时效态WE43合金在3.5 wt.%NaCl溶液中形成了致密且具有3层结构的腐蚀产物膜。采用透射电子显微镜分析膜层的显微组织。保护性膜层为3层结构,从内到外依次为RE_(2)O_(3)层、MgO与RE_(2)O_(3)的混合层和Mg(OH)2与RE_(2)O_(3)的混合层。析出相和稀土元素通过外氧化的方式形成大量稀土氧化物颗粒,这是保护性膜层形成的主要原因。RE_(2)O_(3)与MgO存在以下择优位向关系:(211)晶面和[231]晶向分别与MgO的(002)晶面和[110]晶向平行。因此,稀土氧化物颗粒可以填补疏松MgO膜层的空隙,从而提高了膜层的致密性。内层的RE_(2)O_(3)和MgO与RE_(2)O_(3)的混合层对于保护性膜层的形成起到了重要作用。致密的内层腐蚀产物膜能阻止腐蚀介质与镁基体发生反应。
A dense three-layer corrosion product film was formed on aged WE43 alloy in 3.5 wt.%NaCl solution.The microstructure of the film was analyzed in detail by TEM.The three-layer corrosion product film is composed of RE_(2)O_(3),MgO layer doped with RE_(2)O_(3) and Mg(OH)2 layer doped with RE_(2)O_(3) from the inside to the outside.A large amount of rare earth oxide particles formed both by the outward oxidation of rare earth precipitates and rare earth elements,are the main reason for the formation of the corrosion film.The RE_(2)O_(3) has the preferential orientation with(211)plane and[231]direction parallel to(002)plane and[110]direction of MgO,respectively.Thus,the rare earth oxide particles can fill the gap of porous MgO layer,and improve the compactness of the film.The inner RE_(2)O_(3) layer and mixed layer of MgO and RE_(2)O_(3) play an important role in the formation of the film.The compact inner film can prevent the corrosion medium from reacting with the Mg matrix.
作者
蔡勇
陈翌鹏
闫宏
陈荣石
Yong CAI;Yi-peng CHEN;Hong YAN;Rong-shi CHEN(School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China;Shi-changxu Innovation Center for Advanced Materials,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;School of Materials Science and Engineering,Shandong University of Science and Technology,Qingdao,Shandong 266590,China)
基金
National Natural Science Foundation of China(No.52271107)
Natural Science Foundation of Liaoning Province,China(No.2020-MS-004)
Natural Science Foundation of Shandong Province,China(No.ZR2021ME241)。
