(1. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長(zhǎng)沙 410083；
2. 永杰新材料股份有限公司，杭州 311222)
摘 要: 在3.5% NaCl(質(zhì)量分?jǐn)?shù))溶液中測(cè)定鑄態(tài)和經(jīng)固溶處理的Mg-6Al-5Pb-1.5In鎂合金陽(yáng)極的腐蝕電化學(xué)性能，采用金相(OM)、掃描電鏡(SEM)和能譜分析(EDS)分別研究其顯微組織、截面腐蝕形貌及相組成。結(jié)果表明：固溶后β-Mg17Al12相基本溶入α-Mg基體，降低微電偶腐蝕中陰極與陽(yáng)極的面積比，增大陽(yáng)極自腐蝕速率；Mg2Pb相的自腐蝕電位比鎂基體正，固溶后Pb以Mg2Pb相析出，陽(yáng)極表面腐蝕后晶粒中央的Mg2Pb相并沒(méi)有被腐蝕。Al含量是決定鎂陽(yáng)極中各相腐蝕速率的關(guān)鍵，相表面形成的保護(hù)膜中Al含量越高，對(duì)基體保護(hù)性能越好。
關(guān)鍵字: 鎂陽(yáng)極；固溶處理；腐蝕電化學(xué)性能
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Yongjie New Material Co., Ltd., Hangzhou 311222, China）
Abstract:The corrosion electrochemical properties of as-cast and solid-solution-treated Mg-6Al-5Pb-1.5In 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 β-Mg17Al12 phase dissolves into the α-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 Mg2Pb and the electro-negativity of Mg2Pb is more positive than that of the α-Mg matrix, which results in the un-corroded Mg2Pb 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.
Key words: magnesium anodes; solution treatment; corrosion; electrochemical properties
