(1. 中南大學(xué)材料科學(xué)與工程學(xué)院，長沙 410083；
2. 中國電子科技集團(tuán)第十八研究所，天津 300381)
摘 要: 利用掃描電鏡(SEM)、X射線衍射(XRD)等檢測分析稀土元素La對(duì)Mg-6%Al-5%Pb(AP65)鎂合金(質(zhì)量分?jǐn)?shù))顯微組織的影響，并采用恒電流法、動(dòng)電位極化掃描法和析氫法研究La含量對(duì)AP65鎂合金的腐蝕電化學(xué)性能的影響。結(jié)果表明：加入La能夠使AP65鎂合金α-Mg組織得到細(xì)化，生成針狀稀土相Mg80(Al,La)17和塊狀稀土相Mg17(Al,La)12；添加La提高了AP65鎂合金的電化學(xué)活性、耐腐蝕性能和陽極效率，使AP65的平均電位負(fù)移；當(dāng)La含量為2%(質(zhì)量分?jǐn)?shù))時(shí)，平均電位最負(fù)為-1.73V(vs SCE)。添加6%La使AP65鎂合金的平均析氫速率從1.75mL/(cm2·h)下降到0.02mL/(cm2·h)，并且使陽極效率從74.30%上升到82.31%。
關(guān)鍵字: AP65鎂合金；La；顯微組織；耐蝕性；電化學(xué)性能
（1.School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. The 18th Research Institute of China Electronics Technology Group, Tianjin 300381, China）
Abstract:The microstructures of Mg-6%Al-5%Pb (AP65) alloys (mass fraction) modified by La were investigated by SEM and XRD. The influence of La on the corrosion property of AP65 alloyswere examined by galvanostatic tests, potentiodynamic polarization and hydrogen generation tests. The results show that La addition in AP65 alloys can sufficiently refine α-Mg grain. Net-like phases Mg80(Al,La)17 and massive phases Mg17(Al,La)12 form in AP65 alloys. The La addition improves the electrochemical activity,corrosion resistance and anode efficiency of AP65 alloy. The mean electrode potential of the AP65 alloy shifts negatively with the addition of La. The most negative mean potential of -1.73VSCE occurs in the Mg-6%Al-5%Pb-2%La alloy. The hydrogen generation rate decreases from 1.75 to 0.02mL/(cm2·h)and the anode efficiency increases from 74.30% to 82.31% by adding 6%La to AP65 alloy .
Key words: AP65 Mg alloy; La; microstructure; corrosion resistance; electrochemical property
