摘要
将AZ31镁合金在NaOH、Na2SiO3和Na2B4O7的电解液中进行阳极氧化,考察了乙二胺四乙酸添加剂对阳极氧化膜性能的影响。用扫描电镜观察阳极氧化膜形貌,用X-射线衍射和自带能谱仪对膜层的相组织和元素含量进行分析,用交流阻抗测试氧化膜的耐蚀性能。结果表明,氧化膜主要由Mg O组成,膜层中出现了乙二胺四乙酸的特征元素C和N,Mg Si O3的衍射峰受到抑制。阳极氧化过程中的起弧电压随乙二胺四乙酸含量的增加呈上升的变化趋势。随着乙二胺四乙酸含量的增加,膜层耐蚀性先提高后降低。乙二胺四乙酸质量浓度为7.5 g/L时氧化膜具有最大的阻抗,最优的耐蚀性能。
AZ 31 magnesium alloy was anodized in an environmental friendly electrolyte containing sodium hydroxide,sodium silicate and sodium borate by using ethylenediamine tetraacetic acid（ EDTA） as additive,and influences of EDTA on performance of the anodizing film were investigated. Surface morphologies of the anodizing film was observed by SEM; phase organization and elements content of the anodizing film were analyzed by XRD and energy dispersive spectroscopy（ EDS）; anti-corrosion performance of the anodizing film was characterized by AC impedance test. The results showed that the anodizing film was composed mainly by MgO,C and N（ feature elements of EDTA） were appeared on the film surface and the diffraction peak of Mg SiO3 was depressed. Striking voltage in the anodizing process would increase with the increasing of EDTA concentration. Corrosion resistance of the anodizing film would increase first and then decreased with the increasing of EDTA concentration. When EDTA concentration was 7. 5 g / L,the anodizing film had the maximum impedance and the optimum corrosion resistance.
出处
《电镀与精饰》
CAS
北大核心
2015年第5期1-5,共5页
Plating & Finishing
基金
材料腐蚀与防护四川省重点实验室资助项目(2013CL14
2014CL07)
