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为研究镁合金在人体生理环境下的腐蚀行为,采用阳极极化和电化学交流阻抗谱(EIS)测量技术研究了AZ31镁合金在Hank’s仿生溶液中的电化学腐蚀行为及腐蚀产物形成过程;利用扫描电子显微镜(SEM)和X射线能谱仪(EDS)分析不同浸泡时间腐蚀产物膜的形貌和成分变化。研究结果表明:镁合金AZ31在Hank’s溶液中浸泡最初10min,表面形成新的MgO钝化膜。镁合金的腐蚀经历了点蚀的诱导、点蚀的发展和腐蚀产物层的生成3个阶段,腐蚀过程中除Mg的溶解过程外,还有H2PO-4、HPO2-4、PO3-4、Ca2+在镁合金表面的吸脱附过程。镁合金点蚀处磷酸钙盐沉积较多,表明镁离子的溶解促进了磷酸钙的沉积。
In order to study the corrosion behavior of magnesium alloy in human physiological environment, the electrochemical corrosion behavior and corrosion product formation of AZ31 magnesium alloy in Hank’s bionic solution were studied by anodic polarization and electrochemical impedance spectroscopy (EIS) Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were used to analyze the morphology and composition of the corrosion products at different immersion time. The results show that the AZ31 magnesium alloy is soaked in Hank’s solution for the first 10 minutes and a new MgO passivation film is formed on the surface. The corrosion of magnesium alloy underwent the induction of pitting corrosion, the development of pitting corrosion and the formation of corrosion product layer. In addition to the dissolution process of Mg in the corrosion process, the corrosion of magnesium alloy also included H2PO4, HPO2-4, PO3-4, Ca2 + Suction and desorption process on the surface of magnesium alloy. Magnesium alloy pitting at calcium phosphate deposition more, indicating that the dissolution of magnesium ions promote the deposition of calcium phosphate.