材料期刊网

应用电化学阻抗谱(EIS)连续测试B95铝合金在添加H2O2的0.01mol.L-1 CeCl3溶液中铈盐转化膜的形成过程，通过成膜过程中交流阻抗值的变化研究了H2O2对B95铝合金表面在0.01mol.L-1的CeCl3溶液中的成膜过程的影响，采用等效电路的方式对测试的EIS进行了解析。结果表明与B95铝合金可在铈盐溶液中成膜过程相对应的EIS变化清楚地显示膜层的变化，稀土转化膜的成膜过程可以分成三个阶段：形成阶段，成长阶段和稳定平衡阶段；自然浸泡生成的转化膜不够致密，随在溶液中浸泡时间的延长，转化膜的性能有所下降；添加H2O2后，一方面加快Ce转化膜形成速度，特别是成膜的第一阶段─?───形成阶段，使原需24h的过程缩短为1.5h；另一方面，H2O2促使B95表面转化膜更加致密，能够阻止水在转化膜中的渗透，转化膜的阻抗值呈现逐渐增大的趋势。

Electrochemical impedance spectroscope (EIS) of B95 aluminum alloy in 0.01mol.L-1 CeCl3 solution was investigated to study the film formation and mechanism. Typical EIS spectral changes are clearly observed during the film formation processes. EIS results indicate that Ce(III) film can be formed on the aluminum surface by chemical treatment. EIS is used to make a continuous test on the formation of Cerium when aluminium alloy is immersed in 0.01mol.L-1 CeCl3 solution plus H2O2. A research is done on the process of film formation and mechanism of B95 aluminum alloy through the changes of EIS in the process. Followed is an analysis on the tested EIS based on equivalent circuit. The result shows that the variation of EIS can clearly display the film change of B95 aluminum alloy in Cerium solution. The film formation process of RE conversion film can be divided into three stages: formation stage; growth stage; stable equilibrium stage. The conversion film formed by natural immersion is not compact. With the immersing time going by, the property of the conversion film tends to lose much. The addition of H2O2,, on the one hand, can speed up the formation of cerium conversion film, especially in the first stage—formation stage, and shorten the time from originally 24 hours to 1.5 hours. On the other hand, H2O2 helps to make the conversion film on the surface become more compact and is able to prevent water from permeating the conversion film. The inhibition of conversion coating tends to grow stronger gradually.