摘要
研究了浸泡时间对镁合金微弧氧化涂层耐蚀性的影响并建立了耐腐蚀机理模型。涂层样品在仿生液中总浸泡28 d。采用扫描电镜,X射线衍射仪分析了膜层腐蚀前后的微观组织结构和相组成。通过动电位极化曲线和电化学阻抗谱测试研究膜层的电化学行为。经28 d腐蚀后的样品表面生成了完整的腐蚀产物层。X荧光能谱显示腐蚀层Ca/P摩尔比接近1.67,表明腐蚀表面沉积出的羟基磷灰石具有良好生物兼容性和生物活性。腐蚀产物层的形成减小了样品的腐蚀速率,耐蚀性显著提高。
The effect of immersion time on corrosion behavior of microarc-oxidized AZ31 Mg alloy in a simulated body fluid was studied. The microarc oxidation was performed in an electrolyte of 30 g/L sodium phosphate （Na3PO4） at a voltage of 250 V and a pulse frequence of 3000 Hz for 5 min. Potentiodynamic polarization and electrochemical impedance spectroscopy （EIS） were used to characterize the corrosion behavior. The corrosion current density increases during the first 14 days and then decreases in the subsequent days. The electrochemical impedance is in accord with the result of the corrosion current density. The characterization of corrosion products revealed that hydroxyapatite （HA） was formed on the surface of the samples. The ratio Ca/P of the corrosion products was determined by the X-ray fluorescence （XRF） technique, and the value is around 1.67. The corrosion resistance of the microarc oxidized samples is enhanced due to the formation of a corrosion product after immersion in simulated body fluid for more than 14 days. The corrosion inhibition mechanism of the corrosion process is discussed and presented with a physical model.
出处
《腐蚀科学与防护技术》
CAS
CSCD
北大核心
2013年第5期365-371,共7页
Corrosion Science and Protection Technology
基金
国家重点基础研究发展计划项目(2012CB619100)
国家自然科学基金项目(51072057)资助
关键词
镁合金
浸泡时间
微弧氧化
腐蚀抑制
仿生液
magnesium alloy, immersion time, microarc oxidation, corrosion inhibition, simulated body fluid
