Effect of Microstructure on Electrochemical Performance of Al-Zn-In-Mg-Ti Alloys

The microstructure of Al-5Zn-0.02In-1Mg-0.05Ti alloys,which were the as cast,and the cast ones followed by heat treatments of solid solution,annealing and solid solution plus aging respectively,were comparatively examined.The open circuit potential,working potential, polarization curves and electrochemical impedance spectroscopy(EIS) of them were measured,and then their EIS was analyzed by the equivalent circuit R_L(CR_p(QR_d)(L_1R_(a1))(L_2R_(a2)).The effect of different heat treatments on microstructure and electrochemical performance of Al-Zn-In-Mg-Ti alloy anodes was revealed.The results showed that among the four alloys,the current efficiency and the actual capacitance of the annealed alloy were the highest,which were 83.5%and 2391.03 respectively.That was to say that the amount and size of precipitates of the annealed alloy was moderate,so that the alloy exhibited a quite negative open circuit potential as well as a stable working potential.