阳极氧化膜和微弧氧化膜对5A06铝合金海水腐蚀及力学性能的影响  

Effects of anodization and micro-arc oxidation coatings on corrosion resistance and mechanical properties of 5A06 aluminum alloy

作　　者：李若灿 段体岗 马力[2] 吴建国[3] 赵悦 彭文山 侯健 LI Ruocan;DUAN Tigang;MA Li;WU Jianguo;ZHAO Yue;PENG Wenshan;HOU Jian(Yantai Research Institute,Harbin Engineering University,Yantai 264000,China;National Key Laboratory of Marine Corrosion and Protection,Luoyang Ship Material Research Institute(LSMRI),Qingdao 266237,China;Science and Technology on Reliability and Environmental Engineering Laboratory,Beijing Institute of Structure and Environment Engineering,Beijing 100076,China)

机构地区：[1]哈尔滨工程大学烟台研究院,山东烟台264000 [2]洛阳船舶材料研究所海洋腐蚀与防护全国重点实验室,山东青岛266237 [3]北京强度环境研究所可靠性与环境工程技术重点实验室,北京100076

出　　处：《电镀与涂饰》2024年第8期58-69,共12页Electroplating & Finishing

摘　　要：[目的]研究氧化膜对5A06铝合金海水腐蚀与力学性能的影响。[方法]通过海水浸泡腐蚀试验和应力腐蚀试验,考察了阳极氧化和微弧氧化处理后的铝合金在海水环境中的腐蚀行为和力学性能的变化。[结果]在海水环境下,5A06铝合金及其氧化膜的腐蚀形式以点蚀为主,微弧氧化膜和阳极氧化膜具有良好的耐蚀性。动电位极化曲线和电化学阻抗谱测试结果显示,5A06铝合金裸试样、阳极氧化膜试样和微弧氧化膜试样,在为期30 d的海水浸泡试验后腐蚀电位均发生了明显负移,腐蚀电流密度和维钝电流密度均增大,电荷转移阻抗均减小,表明试样耐蚀性有所下降,其中微弧氧化膜的腐蚀电流密度和维钝电流密度最小,电荷转移阻抗最大,表明微弧氧化膜的耐蚀性高于铝合金及其阳极氧化膜。应力应变测试结果和微观断口形貌显示,相比于阳极氧化试样,应力腐蚀试验后微弧氧化试样的断后伸长损失率和断面收缩损失率均较小,分别为13.79%和6.72%,表明其塑性和韧性较好。[结论]在应力及海水腐蚀介质的耦合作用下,5A06铝合金的耐蚀性和力学性能出现一定程度的下降,微弧氧化和阳极氧化膜都可以提高5A06铝合金的耐蚀性,其中微弧氧化膜的耐蚀性和力学性能更优异。[Introduction]The effects of different oxidation coatings on the corrosion resistance and mechanical properties of 5A06 aluminum alloy need to be studied.[Method]The corrosion behaviors of anodized and micro-arc oxidized 5A06 aluminum alloy in seawater and the variation of their mechanical properties after corrosion were examined by steady-state immersion corrosion test and stress corrosion test.[Result]The pitting corrosion was predominant for 5A06 aluminum alloy and its oxidation coatings in seawater.Both micro-arc oxidation coating and anodization coating exhibited good corrosion resistance.The results of potentiodynamic curve measurement and electrochemical impedance spectroscopy showed that the corrosion potentials of bare,anodized,and micro-arc oxidized 5A06 aluminum alloy specimens were shifted significantly toward the negative direction after 30 days of immersion in seawater,their corrosion current density and passivation current density were increased,and their charge transfer resistance was decreased,indicating a decline in corrosion resistance.The micro-arc oxidation coating exhibited the lowest corrosion current density and passivation current density,and the highest charge transfer resistance among all the specimens,indicating that the corrosion resistance of micro-arc oxidation coating is superior to that of bare aluminum alloy and its anodization coating.Stress-strain test results and fracture micromorphology observation showed that the reduction of elongation after fracture and section shrinkage after stress corrosion test were 13.79%and 6.72%,respectively,for the micro-arc oxidation specimen,both of which were smaller than that of the anodization specimen,indicating that the micro-arc oxidation coating had better plasticity and toughness.[Conclusion]Under the coupled effects of stress and seawater corrosion,the corrosion resistance and mechanical properties of 5A06 aluminum alloy exhibit a certain degree of degradation.Both micro-arc oxidation and anodization coatings can improve the corrosion re

关 键 词：铝-镁合金 微弧氧化 阳极氧化 海洋腐蚀 力学性能 

分 类 号：TG172.5[金属学及工艺—金属表面处理] TG174.451[金属学及工艺—金属学]