Composition and corrosion resistance of cerium conversion films on 2195Al-Li alloy

宋冬¹，冯兴国¹，孙明仁²，马欣新²，唐光泽²

1. School of Materials Science and Engineering, Harbin Institute of Technology2. National Key Laboratory of Science and Technology on Preci-sion Heat Processing of Metals, Harbin Institute of Technology

摘 要：The Ce conversion films on 2195Al-Li alloy without and with post-treatment were studied and the corrosion resistance was evalu-ated as well. The surface morphology was observed by scanning electron microscopy （SEM）, and the chemical composition was characterized by X-ray photoelectron spectroscopy （XPS）. The corrosion behaviors of 2195Al-Li alloy and conversion coating were assessed by means of potentiodynamic polarization curves. The experimental results indicated that after post-treatment the surface quality was improved signifi-cantly. According to XPS, the conversion coating after post-treatment was mainly composed of CeO2, Ce2O3, Ce-OH and a little MoO3 and MoO2. The results of potentiodynamic polarization curves revealed that the conversion coating with post-treatment possessed better corrosion resistance than bare alloy and Ce conversion coating without post-treatment.

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