固溶处理对Al-Zn-Bi-Sn合金组织和电化学性能的影响

将Al-5Zn-0．5Bi-0．03Sn合金在550℃保温10h水淬固溶处理，采用扫描电镜（SEM）和能谱分析（EDX）研究了固溶前后组织形貌和析出相成分，利用CHI660C电化学工作站测试固溶处理前后该牺牲阳极材料的电流效率、在3．5％NaCl溶液中的极化曲线及电化学阻抗谱（EIS）。结果表明，固溶处理后Al-5Zn-0．5Bi-0．03Sn合金牺牲阳极材料电流效率提高了19．57％，铝合金阳极沿晶界分布的偏析相发生球化且偏析相中Zn、Sn元素溶入基体；固溶后合金自腐蚀电位和自腐蚀电流密度均降低；等效电路RS（CRP（QRD））较好地拟合了Al-5Zn-0．5Bi-0．03Sn合金在3．5％NaCl溶液中腐蚀的EIS谱．基本反映了该牺牲阳极材料的电极反应过程。

Influence of Solution Treatment on Microstructure and Electrochemical Properties of Al-Zn-Bi-Sn Alloy

Al-5Zn-0.5Bi-0.03Sn alloy was heated at 550 ℃ for 10 h and subsequently quenched in water. The microstructure and composition of precipitated phase in the alloy befor and after the solution treating were researched by using SEM and EDX, and then the current efficiency, polarization curves and electrochemical impedance spectrum （EIS） in 3.5% NaCl solution were tested in the CHI660C electrochemical workstation. The experimental results show that the current efficiency of Al-5Zn-0.5Bi-0.03Sn alloy sacrificial anode has increased by 19.57% , and that the segregated phases in grain boundary of the aluminum alloy anode have sphericized and Zn and Sn in the segragated phases solubilized into the matrix because of the solution treatment. Both self-corrosion potential and self-corrosion current density of the alloy have decreased after water-quenching. The equivalent circuit Rs （ CRp （QRD）） can precisely fit in EIS of Al-SZn-0.5Bi-0.03Sn alloy in 3.5% NaCl solution, basically reflecting electrod reaction process of the sacrificial anode.