ABSTRACT

The development of temporary protective coatings on magnesium implants is a priority in the biomedical field. In the present study, corrosion rates were determined by various techniques for powder metallurgy Mg and AZ31 magnesium alloy uncoated and coated with phytic acid (PA). Weight loss measurements, potentiodynamic polarisation, and electrochemical impedance spectroscopy were performed to monitor the corrosion evolution in a phosphate-buffered saline solution at 37°C. The corrosion rates of all samples determined from weight losses were higher than those obtained by electrochemical techniques. According to electrochemical data, the initial corrosion current density of the coated samples decreased by three orders of magnitude as compared with that of the bare substrates. However, the protective effect weakened with the testing time due to the presence of microcracks in the PA conversion coating, which indicated the potential applicability of the coated AZ31 alloy as a biodegradable and resorbable temporary implant material for bone repair.

摘要

在镁植入物上开发临时保护涂层是生物医学领域的优先事项。在本研究中，通过各种技术对未涂覆和涂覆植酸 (PA) 的粉末冶金镁和 AZ31 镁合金的腐蚀速率进行测定。进行重量损失测量、动电位极化和电化学阻抗谱以监测 37°C 磷酸盐缓冲盐溶液中的腐蚀演变。由重量损失确定的所有样品的腐蚀速率高于通过电化学技术获得的腐蚀速率。根据电化学数据，与裸基体相比，涂层样品的初始腐蚀电流密度降低了三个数量级。然而，