氧化时间对2024铝合金表面微弧氧化涂层组织与耐蚀性的影响  

Effect of Oxidation Time on Structure and Corrosion Resistance of Micro-arc Oxidation Coating on 2024 Al Alloy Surface

作　　者：温世峰[1] 陈霞[1] 刘军[1] 

机构地区：[1]西北工业大学力学与土木建筑学院,陕西西安710129

出　　处：《热加工工艺》2016年第14期139-143,147,共6页Hot Working Technology

基　　金：国家自然科学基金项目(51405391);高等学校博士学科点专项科研基金项目(20126102120034);西北工业大学基础研究基金项目(3102015ZY032)

摘　　要：采用铝酸盐为主的碱性电解液,在2024铝合金表面制备微弧氧化涂层。通过表面形貌、涂层厚度与生长速率,研究了氧化时间对涂层结构的影响;通过动电位极化曲线及电化学阻抗谱研究了微弧氧化涂层在NaCl溶液中的腐蚀行为。结果表明:微弧氧化涂层表面形成了许多大小不一的微孔,表面的陶瓷颗粒以搭桥的方式在表面不同部位堆积。随着氧化时间的延长,该微弧氧化涂层的厚度逐渐增大,生长速率减慢;经过不同氧化时间的处理,与铝合金基体相比,涂层的腐蚀电压升高,腐蚀电流密度有不同程度的减小;氧化时间20 min的微弧氧化涂层的腐蚀电流密度低、腐蚀电压高,膜层的耐蚀性能较好。Taking alkaline aqueous solution with aluminate, the micro-arc oxidation coating was fabricated on 2024 Al alloy surface .The effects of oxidation time on the coating structure were studied. The potential dynamic polarization and electrochemical impedance spectra were carried out to study the corrosion behavior of MAO coating in NaCl solution. The results indicate that the surface of the oxidation coatings generates many pores with different sizes. Ceramic particles accumulate on the surface in a way of overlapping with each other. With the oxidation time increasing, the thickness of the micro-arc oxidation coating increases, while the growth rate slows down. After oxidation for different time, compared with 2024 Al alloy matrix, for the coating, the corrosion potential increases and the corrosion current density decreases in different degree. When the oxidation time is 20 min, the corrosion current density of micro-arc oxidation coating is low, and the corrosion potential is high, then, the coating has good corrosion resistance.

关 键 词：铝合金 微弧氧化 氧化时间 结构 腐蚀 

分 类 号：TG174.4[金属学及工艺—金属表面处理]