Corrosion Inhibition of SiC-p/5A06 Aluminum Metal Matrix Composite by Cerium Conversion Treatment

This article studies the effects of the CeCl_3 concentrations in conversion solutions with and without addition of NaCl, pH-values of conversion solution, drying temperature, time and temperature of immersion on the Ce-conversion coatings for corrosion protection of the SiC_p/5A06 Al-MMC and 5A06 Al-alloy in the 3.5% NaCl aqueous solution at room temperature. Potentiodynamic polarization tests reveal that the Ce-conversion treatment could markedly improve the pitting corrosion resis-tance of the composite and the matrix alloy in chloride containing environment. The best corrosion resistance effects are ob-tained for the samples treatment in 1%o CeCl_3·7H_2O/3.5% NaCl solution at 45 ℃ for 60 min, followed by drying at 100 ℃ for 30 min. Examinations by means of scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS) and X-ray pho-toelectron spectroscopy (XPS) indicate that this behavior is due to the precipitation of Ce-oxides/hydroxides on the cathodic intermetaUics and the Al-oxide film on the rest of the metal matrix.

作 者： Irfan Aziz Zhang Qi Xiang Min   作者單位： School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100191, China  刊 名： 中國航空學(xué)報（英文版）  ISTIC 英文刊名： CHINESE JOURNAL OF AERONAUTICS  年，卷(期)： 2009 22(6)  分類號： V2  關(guān)鍵詞： cerium   thermal coatings   SiC_p/5A06 Al matrix composites   potentiodynamic polarization   alkaline corrosion