铝在碱性电解液中的阳极行为

Electrochemical behaviour of aluminum in alkaline solution

用电化学方法研究了Al(99.999%￣99.5%)在4mol/LKOH溶液中的阳极行为,结果表明:杂质(Fe,Si,Cu)含量递增,铝的传递电阻变小、腐蚀速度增大,达到稳定开路电位所需时间延长,但50℃时商业铝Al99.82%的极化程度最小,在-1.224V下有400mA/cm2大电流产生;温度升高而铝阳极的活化作用随之增强,但腐蚀也加剧;铝电极在5mmol/LNa2SnO3+4mol/LKOH中的浸泡时间为20min较适合;添加剂Na2SnO3对铝的腐蚀抑制、电化学性能改善都产生有利影响,其最佳浓度为5mmol/L。

Anodic behaviours of Al （ 99.999 % -99.5 % ） have been studied by using electrochemical technique in 4 mol/L KOH solution. The results indicade that Al has high activation performance and high corrossion when temperature rises; When content of impurities （Fe,Si,Cu） increases,Al has high corrossion and achieving stable open circuit potential needs longer time; however ,Al 99.82 % has slower polarization and higher current （400 mA/cm^2） than others at 50 ℃ ;In order to achieve stable Eocp and avoid appearance of Sn apices, 20 min is suitable for Al dipping in 5 mmol/L Na2SnO3 ＋4 mol/L KOH ; good electrochemical behaviour of Al including corrosion-resistance and activation performanc has been achieved by adding additive of Na2SnO3 into 4 mol/L KOH, and 5mmol/L is the most suitable concentration of Na2SnO3.