电流密度对5083铝合金微弧氧化过程与电化学腐蚀性能的影响  

Effect of current density on formation and electrochemical corrosion resistance of micro-arc oxidization coatings on 5083 aluminum alloy

作　　者：王红美[1] 尹艳丽[1] 帅刚[1] 邱骥[1] 马世宁[1] 

机构地区：[1]装甲兵工程学院装备再制造技术国防科技重点实验室,北京100072

出　　处：《材料热处理学报》2016年第3期161-165,共5页Transactions of Materials and Heat Treatment

基　　金：北京自然科学基金(3132024);"十二五"装备预研基金(51327040101)

摘　　要：在含有磷酸钠和钼酸钠的电解液中采用恒流模式对5083铝合金进行微弧氧化。研究了电流密度对氧化电压、膜层生长速率的影响;采用扫描电镜和能谱对氧化膜的表面形貌和成分进行了分析;采用电化学极化曲线测试了氧化膜的耐腐蚀性能。结果表明:在恒电流微弧氧化过程中,氧化电压出现直线快速增长和平稳增长两个阶段,且随着电流密度的增加电压逐渐增大;随着电流密度的增大,氧化膜厚度增加,其表面微弧放电产生的微孔数量逐渐减少,而"火山堆积"状形貌特征越来越明显,电流密度过大氧化膜出现局部剥落,其对氧化膜成分影响不明显;微弧氧化陶瓷膜提高了铝合金基体的耐腐蚀性能,当电流密度为7.5 A/dm2时,微弧氧化膜的自腐蚀电流为1.9×10-8A/cm2,比铝合金基体降低了1个数量级,表现出良好的耐腐蚀性能。5083 aluminum alloy was treated by micro-arc oxidization（ MAO） in a solution containing phosphate and molybdate at different constant applied current densities. The effect of current density on oxidization voltage and the coating thickness was investigated. SEM and EDS analysis were employed to examine the morphology and composition of the ceramic coatings,and the corrosion resistance was measured on an electrochemical workstation. The results show that the oxidization voltage in the MAO process is divided into linearly increasing stage and stably increasing stage,and the oxidization voltage and coating thickness increase gradually with the increase of current density. The number of cavities is decreased while ＂volcano deposit＂characteristic is more evident with the increase of applied current density,and local spalling is observed for the ceramic coatings formed at current density of 9. 0 A / dm^2. The corrosion current density of the ceramic coatings is 1. 9 × 10^- 8A / cm^2,which is one order of magnitude lower than that of the matrix,when the applied current density is 7. 5 A / dm^2.

关 键 词：5083铝合金 微弧氧化 陶瓷膜 电流密度 

分 类 号：TG146.2[一般工业技术—材料科学与工程]