微量CaO对AZ81镁合金显微组织和耐腐蚀性能的影响  

Influence of Trace CaO on Microstructure and Corrosion Resistance of AZ81 Magnesium Alloy

作　　者：陈晓亚[1] 李全安[1,2] 陈君[1,2] 蒋慧珍[1] 周耀[1] 

机构地区：[1]河南科技大学材料科学与工程学院,洛阳471023 [2]有色金属共性技术河南省协同创新中心,洛阳471023

出　　处：《腐蚀科学与防护技术》2016年第1期68-72,共5页Corrosion Science and Protection Technology

基　　金：国家自然科学基金项目(51171059);河南省高校科技创新团队支持计划项目(2012IRTSTHN008);河南省基础与前沿技术研究计划项目(102300410018);河南科技大学第四届研究生创新基金项目(CXJJ-ZR06)资助

摘　　要：利用静态失重法、电化学测试方法、结合SEM和XRD等方法,研究了Ca O添加量为0,0.1%,0.5%和0.9%(质量分数)的AZ81镁合金显微组织和耐腐蚀性能。结果表明:当Ca O的添加量为0.5%时,合金的晶粒得到明显细化,合金主要由α-Mg基体和Mg17Al12相组成,同时在合金中生成了新相Al2Ca和Mg2Ca;随着Ca O添加量的增加,AZ81镁合金在3.5%(质量分数)Na Cl溶液中的腐蚀速率先降低后升高,自腐蚀电位先升高后降低,自腐蚀电流密度先减小后增大,当Ca O的添加量为0.5%时合金的腐蚀速率和自腐蚀电流密度最小,自腐蚀电位最高,耐腐蚀性能最好。Effect of the addition amount of Ca O（0, 0.1% 0.5% and 0.9%（mass fraction） respectively） on the microstructure and corrosion resistance of AZ81 Mg-alloy was studied by means of scanning electron microscopy, XRD, static mass loss and electrochemical measurement. The results show that： when the Ca O amount was 0.5%, the grains of the alloy are refined obviously; the alloy is mainly composed of α- Mg matrix and Mg17Al12 phase and there are also new phases Al2 Ca and Mg2 Ca generated in the alloy; along with the increase amount of Ca O addition the corrosion rate of AZ81 Mg-alloy in 3.5%Na Cl solution increases firstly and then decreases, while the free corrosion potential rises firstly and then falls, in the contrast the free corrosion current density of the alloy reduces firstly and then rises; when the addition amount of Ca O was 0.5% the free corrosion rate and corrosion current density of the alloy are the smallest and the corrosion potential is the highest,therefore, the alloy possesses the best corrosion resistance property.

关 键 词：CAO AZ81镁合金 显微组织 耐蚀性能 

分 类 号：TG172[金属学及工艺—金属表面处理]