(中南大学 材料科学与工程学院，长沙 410083)
摘 要: 采用熔炼铸造和塑性变形方法制备Mg-Al-Pb-La镁合金。采用扫描电镜和X射线衍射等方法研究轧制对Mg-Al-Pb-La镁合金显微组织的影响，采用动电位极化和恒电流放电等方法研究轧制对Mg-Al-Pb-La镁合金腐蚀电化学行为的影响。结果表明：轧制使Mg-Al-Pb-La镁合金的晶粒细化、第二相破碎、再结晶程度降低、Mg-Al-Pb-La镁合金的放电活性增强、耐蚀性变差和阳极效率降低；当轧制变形量为40%时，镁合金的综合放电性能优良，在电流密度180 mA/cm2下平均放电电位和阳极效率分别为-1.749 V (vs SCE)和(82.9±0.2)%。
关键字: Mg-Al-Pb-La镁合金；轧制；显微组织；腐蚀电化学行为
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The Mg-Al-Pb-La alloy was prepared by melting and casting as well as plastic deformation. The effect of rolling on microstructure of Mg-Al-Pb-La alloy was investigated by scanning electron microscopy, X-ray diffractometry and electron backscatter diffractometry. The effect of rolling on electrochemical corrosion behavior was studied by potentiodynamic polarization and galvanostatic measurements. The results show that the discharge activity of the rolled Mg-Al-Pb-La alloys is enhanced. It is related with the refined grains, fractured and homogeneously distributed second phases, and the lowered recrystallization degree of Mg-Al-Pb-La alloy after hot rolling. The Mg-Al-Pb-La alloy with critical rolling deformation of 40% exhibits good discharge performance with strong discharge activity (-1.749 V (vs SCE)) and a relatively high anodic efficiency of (82.9±0.2)%, while the alloy under rolling deformation of 60% exhibits the worst corrosion resistance whose corrosion current density is (49.8±1.3) μA/cm2.
Key words: Mg-Al-Pb-La magnesium alloy; rolling; microstructure; electrochemical corrosion behavior
