Al6061/SiC_p复合材料表面Ce转化膜腐蚀行为的研究

STUDY ON THE CORROSION BEHAVIOR OF Ce CONVERSION COATINGS ON Al6061/SiCp COMPOSITES

利用金相和 Ｘ射线能谱分析了 Ａ１６０６１／ＳｉＣｐ复合材料表面 Ｃｅ转化膜的腐蚀行为实验表明： Ｃｅ转化膜在 ＮａＣｌ溶液中的腐蚀以点蚀开始，点蚀处基体为 ＳｉＣ颗粒的富集区根据 Ｍａｎｓｆｅｌｄ点腐蚀模型等效电路，通过电化学阻抗谱（ＥＩＳ）研究了 Ｃｅ转化膜在 ＮａＣｌ溶液中的腐蚀程度；转化膜在 ＮａＣＩ溶液中浸泡时间较短的情况下，等效电路中的 Ｗａｒｂｅｒｇ阻抗可忽略。

Corrosion behavior of Ce conversion coatings on A16061/SiC. composites was examined by optical microscope and energy dispersive spectroscopy (EDS). The results showed that corrosion of coatings in NaCI solution was initiated by pitting whose substrate was concentrated with SiC particles. According to the equivalent circuit of pitting model illustrated by Mansfeld, pitting growth of Ce conversion coatings was examined by employing electrochemical impedance spectroscopy (EIS). Warberg impedance could be ignored under the circumstance of short term exposing Ce conversion coatings to NaCI solution, this led to investigate the pitting growth by simplifying the equivalent circuit.