纳米二氧化铈对铝合金环氧镁铝复合涂层的防护作用研究

Research on the Protective Effects of Nano CeO_(2)on Epoxy Magnesium Aluminum Composite Coatings on Aluminum Alloy

为了获得耐腐蚀性能较好的涂层,采用一定质量的铝粉代替镁粉,并添加纳米二氧化铈,制备了改性的铝合金表面环氧镁铝复合涂层。采用马丘测试、划叉浸泡实验、X射线衍射分析、扫描电子显微镜等方法,研究了镁粉、铝粉及二氧化铈对环氧镁铝复合涂层的防护作用,并得到二氧化铈与镁粉和铝粉的协同保护机理。结果表明:当镁粉质量分数为30%、铝粉质量分数为20%时,环氧镁铝复合涂层具有较好的耐腐蚀性能。纳米二氧化铈在涂层中的最佳填充量为5%时,可以增强复合涂层对铝合金基体的防护作用。镁粉、铝粉粒子在复合涂层中有大量的分布,粒径较大。少量的纳米二氧化铈粒子在复合涂层中呈球状分布、粒径较小,且涂层形貌均匀致密,屏蔽性能较好。改性后的复合涂层显著增强了铝合金在服役环境中的耐腐蚀性能。

In order to obtain the coatings with better corrosion resistance performance,magnesium powders were replaced by a certain quality of aluminum powders to prepare the epoxy magnesium aluminum composite coatings with adding nano CeO_(2)on aluminum alloy.The effects of magnesium powder,aluminum powder and nano CeO_(2)on the protective effects of epoxy magnesium aluminum composite coatings on aluminum alloy were studied through Machu test,cross immersion experiment,X-ray diffraction and scanning electron microscope.Then the synergistic protection mechanism of nano CeO_(2)with magnesium powders and aluminum powders was obtained.The results indicated that the epoxy magnesium aluminum composite coating had good corrosion resistance when the amount of magnesium powders added was 30wt.%and the amount of aluminum powders added was 20wt.%.In addition,when the optimal filling amount of nano CeO_(2)in the coating was 5wt.%,it could significantly enhance the protective effect of the epoxy magnesium aluminum composite coatings.Furthermore,the magnesium powders and the aluminum powder particles had the large distribution and the large particle size in the composite coatings.A small amount of nano CeO_(2)particles with the smaller particle size were distributed in spherical shapes in the composite coatings.The composite coatings were very uniform and dense with the good shielding performance.Therefore,the modified composite coatings significantly enhanced the corrosion resistance of aluminum alloys in service environments.