【摘要】 研究了两种钙含量相同、锌含量(质量分数)不同的镁合金(Mg-1.0%Ca-0.3%Zn和Mg-1.0%Ca-1.0%Zn)在模拟体液(Simulated body fluid,SBF)中的腐蚀行为。通过三电极体系动电位法、析氢法、pH计和扫描电子显微镜对合金在SBF中的极化曲线、浸泡过程中析出氢气量、SBF的pH值变化以及浸泡后的合金形貌进行分析和研究。结果表明:两种合金的耐腐蚀性均好于纯镁,其中合金Mg-1.0%Ca-1.0%Zn较合金Mg-1.0%Ca-0.3%Zn在SBF中极化阻力大,析出氢气量减少,在1~48h内SBF溶液的pH值增加较快,SBF溶液的碱化较快;浸泡后合金Mg-1.0%Ca-1.0%Zn表面较平整,合金的耐腐蚀性较好,腐蚀速率能基本满足作为体内植入生物材料的要求,且在SBF中日离子溶出量不超过人体耐受量的前提下,其体内植入物制品表面积上限可达179cm2,具有较大的实用性。更多还原

【Abstract】 The corrosion performance in the simulated body fluid(SBF)of Mg-1.0wt.%Ca-0.3wt.%Zn and Mg-1.0wt.%Ca-1.0wt.%Zn were investigated.The polarization curve in the SBF was obtained by three electrode system.The hydrogen evolution rate was obtained via hydrogen evolution method.The pH value of the SBF and morphology of alloy were characterized by precision pH meter and scanning electron microscope(SEM)respectively.The results show that the polarization resistance of Mg-1.0wt.%Ca-1.0wt.%Zn magnesium alloy was larger and the hydrogen evolution decreased obviously;the pH value of the SBF within 48hwas increased quickly and alkalization of the SBF has been accelerated.The surface of the Mg-1.0wt.%Ca-1.0wt.%Zn alloy soaked in SBF was perfect and its corrosion resistance was better.Moreover,the corrosion velocity can serve the needs of implant material in body.Under the conditions of the concentration of ion released every day in SBF does not exceed the human tolerance,the max surface area of in vivo implant of this alloy reached 179cm2.更多还原