Mg-2Zn-0.2Mn-xCa生物医用镁合金的改性与降解性研究

发布时间：2018-06-18 16:07

  本文选题：骨修复材料 + 镁合金　； 参考：《成都理工大学》2017年硕士论文

【摘要】：由于医疗技术水平的大力发展,全球总人口在不断的增长并趋向于老年化,这导致了突发性骨折疾病的比例在不断的增长。而骨折的治疗通常需要辅助支架的固定支承,为患骨组织提供相对固定的组织修复环境。因此,人们近年来对骨修复支架材料的需求在显著增长。目前临床普遍使用的金属骨修复材料通常需要进行二次取出手术,这给病人增加了痛苦和额外的医疗费用。而镁合金具有可降解性和较好的力学相容性,有望作为可降解骨修复材料对骨折进行治疗。但目前,由于镁合金降解速率与人体患骨组织的愈合速率存在着较大的差异,导致在一些愈合缓慢的组织处,过快的镁合金降解速率将导致其力学性能提前丧失,进而影响患骨组织的愈合。因此本课题试图在Mg-2Zn-0.2Mn合金的基础上添加含Ca元素,并结合不同热处理工艺对Mg-2Zn-0.2Mn合金进行改性,以期能在一定程度上对镁合金降解速率以及力学性能进行调控,最后采用细胞相容性实验对热处理改性镁合金进行细胞相容性评价。首先采用井式电阻炉熔炼了Mg-2Zn-0.2Mn-0.1Ca、Mg-2Zn-0.2Mn-0.4Ca、Mg-2Zn-0.2Mn-0.7Ca三种不同含Ca比合金,并对样品进行金相显微镜、扫描电镜、显微硬度检测仪、X射线衍射仪等测试分析。结果表明,随着含Ca比的增加,Mg-2Zn-0.2Mn-xCa合金的显微硬度值由47.54HV增加到了61.00HV。对Mg-2Zn-0.2Mn-xCa合金的三种不同含Ca比成分样品,采用析氢浸泡实验进行分析测试。结果表明,随着含Ca比的增加,合金的平均析氢量成先减后增的趋势。在含Ca比为0.4%时,合金具有最低的平均析氢量2.588ml/cm2/Day,而在含Ca比为0.7%时,合金具有最高的平均析氢量2.993ml/cm2/Day。探究热处理对Mg-2Zn-0.2Mn-0.1Ca、Mg-2Zn-0.2Mn-0.4Ca两种合金的腐蚀降解速率的影响。结果表明,随着热处理温度的增加,两种合金的平均析氢量成减小的趋势。Mg-2Zn-0.2Mn-0.1Ca合金经过380℃、420℃热处理后的平均析氢量分别为2.124ml/cm2/Day、1.538ml/cm2/Day,相对铸态分别降低了28.76%、43.77%。Mg-2Zn-0.2Mn-0.4Ca合金经过380℃、420℃热处理后的平均析氢量分别为1.489ml/cm2/Day、1.291ml/cm2/Day,相对铸态分别降低了42.49%、50.14%。
[Abstract]:Due to the rapid development of medical technology, the global population is increasing and tends to be aging, which leads to the increasing proportion of sudden fracture diseases. The treatment of fracture usually requires the fixed support of auxiliary scaffold to provide a relatively fixed tissue repair environment for the affected bone tissue. As a result, the demand for bone-repair scaffolds has increased significantly in recent years. Metal bone repair materials currently commonly used in clinical use usually require secondary removal, which adds pain and additional medical costs to patients. Magnesium alloy has biodegradability and good mechanical compatibility, which is expected to be used as biodegradable bone repair material to treat fracture. However, at present, the degradation rate of magnesium alloy is different from the healing rate of human bone tissue, which leads to the premature loss of mechanical properties of magnesium alloy in some slowly healing tissues. And then affect the healing of bone tissue. Therefore, this paper tries to add Ca on the basis of Mg-2Zn-0.2Mn alloy and modify Mg-2Zn-0.2Mn alloy with different heat treatment process, in order to regulate the degradation rate and mechanical properties of magnesium alloy to a certain extent. Finally, the cytocompatibility of heat treated magnesium alloy was evaluated by cytocompatibility test. Mg-2Zn-0.2Mn-0.1CaG2Zn-0.2Mn-0.2Mn-0.2Mn-0.2Mn-0.7Ca alloys with different Ca content were first melted in a well resistance furnace. The samples were analyzed by metallographic microscope, scanning electron microscope, microhardness tester and X-ray diffractometer. The results show that the microhardness of Mg-2Zn-0.2Mn-xCa alloy increases from 47.54HV to 61.00HV with the increase of Ca content. Three samples of Mg-2Zn-0.2Mn-xCa alloy with different Ca ratios were analyzed and tested by hydrogen evolution immersion test. The results show that with the increase of Ca content, the average hydrogen evolution of the alloy decreases first and then increases. The alloy has the lowest average hydrogen evolution rate of 2.588ml / cm ~ 2 / Daywhen Ca content ratio is 0.4m, while the alloy has the highest average hydrogen evolution rate of 2.993ml / cm ~ 2 / Daywhen Ca content ratio is 0.7ml / cm ~ (-2). The effect of heat treatment on corrosion degradation rate of Mg-2Zn-0.2Mn-0.2Mn-0.4Ca alloy was investigated. The results show that with the increase of heat treatment temperature, The average hydrogen evolution of Mg-2Zn-0.2Mn-0.1Ca alloy after heat treatment at 380 鈩，

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