单 位：
重庆机床(集团)有限责任公司;西南大学工程技术学院
关键词：
微弧氧化;AZ31B;封孔处理;耐腐蚀性能
摘 要：
为了提高AZ31B镁合金微弧氧化膜耐腐蚀性能,分别采用沸水和15%石蜡水溶液对其进行封孔处理,并对未封孔和用沸水及15%石蜡水溶液封孔后三种状态下氧化膜的耐腐蚀性与SEM形貌进行对比研究.耐腐蚀性测试结果显示,沸水和15%石蜡水溶液封孔均可提高氧化膜的耐腐蚀性能,其中,15%石蜡水溶液封孔效果更为显著.SEM测试结果与分析显示,沸水与石蜡水溶液的封孔机理不同.沸水封孔后,封堵放电通道的是MgO(氧化膜的主要成分)与水的反应产物—Mg(OH)2.因此,随封孔时间的延长,膜层的损害程度增大,其耐腐蚀性反而降低.石蜡水溶液封孔的本质是溶体浸润氧化膜并在放电通道中冷却析出而达到封堵效果,因此,在石蜡溶液浓度一定的条件下,随封孔时间的延长,膜层的浸润性增加,其耐腐蚀性增强.
译 名：
Effect of Sealing Treatment on Corrosion Resistance of Micro-Arc Oxidation Coatings for AZ31B Mg Alloy
作 者：
ZHAI Yan-bo;CHEN Hong-bing;MEI Zhen;School of Engineering and Technology,Southwest University;Chongqing Machine Tool(Group)Co.,Ltd;
关键词：
Micro-arc oxidation(MAO);;AZ31B;;sealing treatment;;corrosion resistance
摘 要：
To increase the corrosion resistance of the micro-arc oxidation(MAO)coatings for AZ31B Mg alloy,the discharge holes of the coatings were sealed by boiling water or aqueous solution with 15%wt paraffin,and the corrosion resistance and SEM images of the coatings were compared.The results of the corrosion resistance test showed that either of the sealing treatments increased the corrosion resistance of coatings,but aqueous solution with 15%wt paraffin had better hole sealing effects.SEM image analysis of the coatings revealed that boiling water and paraffin aqueous solution had different sealing mechanisms. With boiling water sealing,Mg(OH)2,the reaction product of MgO(the main composition of the coatings)and H2O,stopped the discharge holes.Therefore,as the discharge time was prolonged,the damage suffered by the coatings increased and the corrosion resistance declined.The essence of sealing by paraffin aqueous solution was that the aqueous solution would be cooled and precipitated after infiltrating the MAO coatings.Consequently,on the condition that the concentration of paraffin aqueous solution was constant, the infiltration of coatings increased and the corrosion resistance was improved with the prolonging of sealing time.
