A356铝合金扫描式微弧氧化涂层的成膜过程及耐腐蚀性能  

Growth Process of Scanning Micro Arc Oxidation Coatings on A356 Alloy and their Corrosion Resistance

作　　者：夏伶勤[1] 韩建民[1] 杨莎[1] 杨智勇[1] 李卫京[1] XIA Lingqin HAN Jianmin YANG Sha YANG Zhiyong LI Weijing(School of Mechanical Electric and Control Engineering, Beijing Jiaotong University, Beijing 100044, China)

机构地区：[1]北京交通大学机械与电子控制工程学院,北京100044

出　　处：《材料研究学报》2016年第12期914-920,共7页Chinese Journal of Materials Research

基　　金：国家自然科学基金51371022;中央高校基本科研业务费专项资金2015JBM076;中国铁路总公司科技研究开发计划课题2015008-C资助项目~~

摘　　要：采用扫描式微弧氧化(SMAO)技术在A356铝合金表面制备了陶瓷涂层。测定了反应过程中涂层的电压-时间、动力学生长曲线,研究了涂层的显微组织、成分分布,分析涂层的相组成及显微硬度分布,并比较了氧化前后极化曲线的变化。结果表明,在硅酸盐溶液中获得的涂层主要由α-Al_2O_3、γ-Al_2O_3和莫来石组成,涂层与基体呈现良好的冶金结合。与A356传统式微弧氧化(CMAO)涂层相比,SMAO涂层中α-Al_2O_3含量略多、孔隙率更低,显微硬度更高。此外,两种氧化处理之后,铝合金的耐腐蚀能力均得到显著提高。Al-alloy A356 was treated by scanning micro arc oxidation （SMAO） method. The voltage- time and coating thickness-time curves were recorded. The microstructure, composition, phase constitu- ent and microhardness profile of coatings werecharacterized. The corrosion behavior of the composite was evaluated by polarization test. Results show that the coating deposited in silicate electrolyte consists of α-Al2O3, γ-Al2O3 and mullite. The coating and the substrate presented excellent metallurgical bonding. Compared with the common micro arc oxidation （CMAO） coatings on A356 alloy, the SMAO coating con- tained higher amount of α-Al2O3 phase withless porous, and possessed higher micro hardness. However, af- ter treatment by either CMAO or SMAO, the corrosion resistance of A356 alloy was significantly improved. KEY WORDS materials failure and protection, Al-alloy, scanning micro arc oxidation, ceramic coating, corrosion resistance

关 键 词：材料失效与防护 铝合金 扫描式微弧氧化 陶瓷膜 腐蚀性能 

分 类 号：TB304[一般工业技术—材料科学与工程] TG174[金属学及工艺—金属表面处理]