铝合金表面铈锰化学转化

以硝酸铈和高锰酸钾为主盐，在6063铝合金表面制备了Ce-Mn化学转化膜。研究了室温下成膜时间、转化液pH值、硝酸铈和高锰酸钾浓度对Ce—Mn转化膜电化学性能的影响，获得了最佳成膜工艺：7g／LCe（NO3）3，2g／LKMnO4，时间9min，pH值2．3。采用极化曲线考察了所得转化膜的耐蚀性，并通过扫描电镜和能谱仪分析了膜的表面微观形貌和组成。结果表明：Ce．Mn转化膜比6063铝合金具有更低的腐蚀电流密度和更大的极化电阻，表现出良好的耐腐蚀性能；Ce-Mn转化膜主要成分是铝、镁、铈、锰和氧。

Preparation and Corrosion Resistance of Cerium-Manganese Chemical Conversion Coating on Aluminum Alloy Surface

Ce-Mn conversion coating was prepared on the surface of 6063 aluminum alloy using Ce(NO 3) 3 and KMnO 4 as the major salts.The effects of film-formation time and pH value of the conversion fluid as well as concentration of Ce(NO 3) 3 and KMnO 4 on the electrochemical properties of the conversion coating were investigated,and the optimal condition for preparing the conversion coating was established.Moreover,the corrosion resistance of the conversion coating was evaluated based on polarization curve method,and a scanning electron microscope and an energy dispersive spectrometer were performed to analyze the morphology and elemental composition of the conversion coating.It was found that the optimal conversion fluid consisted of 7 g/L Ce(NO 3) 3 and 2 g/L KMnO 4,and the optimal film-formation time and pH value of the conversion fluid were 9 min and 2.3 respectively.As-obtained Ce-Mn conversion coating was mainly composed of Al,Mg,Ce,Mn and O.As compared with the Al alloy substrate,as-obtained Ce-Mn conversion coating possessed lower corrosion current density and higher polarization resistance,showing good corrosion resistance.