【摘要】 采用电化学交流阻抗技术(EIS)对7B04铝合金的一种阳极化膜层在加速老化试验过程中的阻抗变化进行了原位测试,分析了其腐蚀失效的特征.结果表明,随加速试验的进行,硫酸阳极化膜层的失光率和色差变化较小,属不失光或很轻微失光和不变色;腐蚀前,阳极化膜的多孔层常相位元件的幂指数n相对较小,仅0.61,说明多孔层孔洞分布比较不均匀.随试验时间增加,n值逐渐增大并接近1,多孔电阻Rpo也逐渐增加,且后期增加幅度加大,这是由于沉淀物的部分封堵与耐蚀钝化膜的共同作用;阳极化膜划痕处的局部交流阻抗随试验时间增加不断减小,是由于划痕处金属发生了腐蚀反应所致,划痕处的阻抗增大则是由于划痕处被腐蚀产物覆盖所致.更多还原

【Abstract】 The variation of electrochemical impedance of an anodic oxidation film on aeronautical aluminum alloy 7B04 during accelerated degradation test was studied using electrochemical impedance spectroscopy(EIS).It has been found that the gloss and the color difference of sulfuric acid anodic oxidation film had little change during the test.n in CPE of porous layer was very small and was about 0.61.But with the prolonged of corrosion time,n increased gradually and reached to 1,also the resistance Rpo of the porous layer increased gradually.That was due to the effect of the blocking of the corrosion product and the passivation film.The local electrochemical impedance of the scratched area decreased with the degradation test,that was caused by the corrosion reaction in the scratched area,while the increase in the fifth period was due to the coverage of the corrosion products in the scratched area.更多还原