双氧水和pH值对可降解挤压态Mg-0.5Sr合金腐蚀行为的影响

Effects of hydrogen peroxide and pH on corrosion behavior of a biodegradable as-extruded Mg-0.5Sr alloy

模拟骨科植入材料植入体内时的生理环境,采用浸泡测试、动电极化测试和电化学阻抗测试研究了模拟生理环境中双氧水浓度和pH值变化对可降解挤压态Mg-0.5Sr合金腐蚀行为的影响。结果表明,在不同pH值(7.4和5.2)的Hank溶液中添加H_2O_2促进腐蚀反应,增加H_2O_2浓度进一步加速腐蚀。降低pH值不仅导致镁合金腐蚀速率增加,而且改变了镁合金的腐蚀机理。结果表明模拟植入时的生理环境加速了镁合金植入体的腐蚀,该研究为可降解镁合金骨科植入体的设计、选择和临床应用提供了重要的信息。

A simulated physiological environment after implantation was used,and the effects of H2O2 and pH on the corrosion behavior of a biodegradable as-extruded Mg-0.5Sr alloy in Hank＇s solution were investigated by using immersion test,potentiodynamic polarization test and electrochemical impedance spectroscopy test.The results showed that the addition of H_2O_2 in Hank＇s solution with different pH（7.4and 5.2）promoted the corrosion reaction,and a higher H2O2 concentration further accelerated the corrosion reaction.The lower pH not only resulted in a higher corrosion rate of magnesium alloy,but also changed its corrosion mechanism.The present investigation indicated that the simulated physiological environment after implantation accelerated the corrosion of magnesium alloy implants,which provided us some important information about design,selection and clinic use of biodegradable magnesium alloy orthopedic implants.