β-Mg_(17)Al_(12)相含量对AZ91镁合金腐蚀行为的影响  

Influence of β-Mg_(17)Al_(12) Phase Content on Corrosion Behavior of AZ91 Magnesium Alloy

作　　者：白力静[1] 张华[1] 袁颖[2] 杨欣[1] 王爱娟[1] 

机构地区：[1]西安理工大学材料科学与工程学院,陕西西安710048 [2]西安理工大学高等技术学院,陕西西安710082

出　　处：《西安理工大学学报》2011年第1期31-35,共5页Journal of Xi'an University of Technology

基　　金：国家十一五科技支撑计划资助项目(2008BAE63B00);西安理工大学校基金资助项目(210802)

摘　　要：采用不同的时效工艺制备不同β-Mg17Al12相含量的AZ91镁合金。通过在重量百分比为3.5%的NaCl水溶液静态浸泡腐蚀实验研究β相对镁合金腐蚀行为的影响,通过腐蚀形貌、腐蚀失重率及电化学腐蚀电流、电位等进行验证实验。结果表明AZ91镁合金的腐蚀过程主要分为α-Mg的溶解、微电偶腐蚀、Mg(OH)2钝化膜的形成及β相的机械阻挡。β相含量多少的不同对四个过程的影响程度不同。β相含量为13%时镁合金的耐蚀性能最佳,小于13%时β相的电偶作用大于其阻碍作用,大于13%时β相的阻碍作用大于电偶作用,β相含量过高时AZ91镁合金耐蚀性更差。AZ91 magnesium alloy samples with different β contents were prepared by aging treatment.The influence of β on Mg alloy can be evaluated in terms of their corrosion behaviors in an aerated NaCl solution which NaCl percent weight in volume is 3.5% by corrosion morphology,lost weights and polarization curves in NaCl solution which NaCl percent weight in volume is 3.5%.The results show that the magnesium alloy corrosion process can be divided into α-Mg dissolution,micro-galvanic corrosion,the formation of Mg（OH）2 passive film and mechanical barrier effect of β phase and the influence degree is varied for four processes.The corrosion resistance of 13% β phase sample is best.When β content is less than 13%,the galvanic effect greater than baffling;while β content is more than 13%,baffling effect is greater than galvanic,but the higher is β content,the poorer AZ91 magnesium alloy corrosion resistance will be.

关 键 词：AZ91镁合金 Β相 含量 腐蚀行为 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TG174[金属学及工艺—金属材料]