材料工程Issue(12)：1-6,6.
AZ31镁合金搅拌摩擦焊接头微弧氧化表面防护研究
Surface Protection of Friction Stir Welding Joint for AZ31 Magnesium Alloy Coated by Microarc Oxidation
摘要
Abstract
A uniform ceramic coating on friction stir welding (FSW) joint of AZ31 magnesium alloy was fabricated by microarc oxidation (MAO) in silicate electrolyte. Microstructure, phase constituent and microhardness profile of the MAO coating at the different zones of FSW joint were analyzed. The influence of microarc oxidation surface treatment on corrosion behaviors of FSW joint was evaluated by immersion and potentiodynamic polarization tests. The results show that hardness of stir zone is higher than that of base alloy, but the hardness of heat-affected zone is lower than that of base alioy. However, the microhardness of MAO coating at different zones of FSW joint is the same, which is about seven times higher than that of AZ31 base alloy. After immersion test in 3. 5%NaCl(mass fraction) solution, the serious pitting corrosion on heat-affected zone takes place, but no pitting corrosion is observed on the MAO coating surface. In addition, the heat-affected zone of FSW joint has a lower corrosion potential and higher corrosion current density, but the corrosion current density of MAO coating at different zones is very close, which is much lower than that of bare AZ31 magnesium alloy. So the MAO surface treatment can significantly improve the corrosion resistance of FSW joint of AZ31 magnesium alloy.关键词
微弧氧化/搅拌摩擦焊/AZ31镁合金/腐蚀Key words
microarc oxidation/friction stir welding/AZ31 magnesium alloy/corrosion分类
矿业与冶金引用本文复制引用
薛文斌,陈廷芳,李永良,邹志锋,刘晓龙,赵衍华..AZ31镁合金搅拌摩擦焊接头微弧氧化表面防护研究[J].材料工程,2012,(12):1-6,6.基金项目
国家自然科学基金项目资助(51071031) （51071031）
北京市自然科学基金项目资助(2102018,2122017) （2102018,2122017）
中央高校基本科研业务费专项资金项目资助(211105562GK) （211105562GK）
