固溶处理对Mg-6Al-5Pb-1.5In阳极腐蚀电化学性能的影响  

Effects of solution treatment on corrosion electrochemical properties of Mg-6Al-5Pb-1.5In anodes

作　　者：金和喜[1,2] 王日初[1] 彭超群[1] 石凯[1] 陈雅谨[1] 许泽辉 

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]永杰新材料股份有限公司,杭州311222

出　　处：《中国有色金属学报》2013年第2期403-409,共7页The Chinese Journal of Nonferrous Metals

基　　金：民口配套国家攻关资助项目(MKPT-02-181)

摘　　要：在3.5%NaCl(质量分数)溶液中测定铸态和经固溶处理的Mg-6Al-5Pb-1.5In镁合金阳极的腐蚀电化学性能,采用金相(OM)、扫描电镜(SEM)和能谱分析(EDS)分别研究其显微组织、截面腐蚀形貌及相组成。结果表明:固溶后β-Mg17Al12相基本溶入α-Mg基体,降低微电偶腐蚀中阴极与阳极的面积比,增大阳极自腐蚀速率;Mg2Pb相的自腐蚀电位比镁基体正,固溶后Pb以Mg2Pb相析出,阳极表面腐蚀后晶粒中央的Mg2Pb相并没有被腐蚀。Al含量是决定镁阳极中各相腐蚀速率的关键,相表面形成的保护膜中Al含量越高,对基体保护性能越好。The corrosion electrochemical properties of as-cast and solid-solution-treated Mg-6Al-5Pb-l.5In alloy anodes were examined in 3.5% NaCl （mass fraction） solution. The microstructures, cross-sectional corrosion morphologies and composition of phases in the anodes were studied by optical microscopy （OM）, scanning electronic microscopy （SEM）and energy dispersive spectrometry （EDS）, respectively. The experimental results show that, the fl-Mgl7All2 phase dissolves into the a-Mg matrix, the cathode-to-anode area ratio of the anodes decreases, and the self-corrosion rates increase after solution treatment. Pb segregates in the form of MgzPb and the electro-negativity of Mg2Pb is more positive than that of the a-Mg matrix, which results in the un-corroded MgzPb existing in the center of the corroded area at the surfaces of anodes. The aluminum content is a dominant factor of corrosion rate in magnesium anodes, and the higher the aluminum content of the protective film is, the better the protective properties to matrix is.

关 键 词：镁阳极 固溶处理 腐蚀电化学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]