【作者】 周波；

【导师】 李峻峰；

【作者基本信息】 成都理工大学 ， 材料加工工程， 2017， 硕士

【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%。更多还原

【Abstract】 As the level of medical technology has been developed greatly,the global population has been continuously growing and tends to the problem of aging,which results in a constant increase in the proportion of sudden fracture disease.The treatment of fractures usually requires a fixed support for the support scaffold,providing a relatively fixed tissue repair environment for bone tissues.Therefore,in recent years,the demand for bone repair stent material has been increased dramatically.Commonly used metal bone repair materials usually require secondary removal surgery,which adds more pains and extra medical expenses to the patients.With biodegradability and good mechanical compatibility,the magnesium alloy has a great potential as a degradable bone repair materials for the treatment of fracture disease.However,nowadays,due to the degradation rate of magnesium alloy and human bone tissue healing rate was significantly different,too fast degradation rate of magnesium alloy will lead to its early loss of mechanical properties,thereby affecting the healing of bone tissue.Thus,this paper attempts the new process to modify the Mg-2Zn-0.2Mn alloy by adding different Ca-containing and different heat treatment processes in order to control the degradation rate of the alloy to a certain extent,and finally,employing the cell compatibility test to evaluate the cell compatibility of heat treated modified magnesium alloy.Well-type resistance furnace has been firstly used to smelt three different Ca-containing alloys,such as Mg-2Zn-0.2Mn-0.1Ca,Mg-2Zn-0.2Mn-0.4Ca,Mg-2Zn-0.2Mn-0.7Ca,and the samples were analyzed by using a metallographic microscope,scanning electron microscopy,micro-hardness testing equipment,X-ray diffractometer.The results show that,with the increase of Ca containing,the microhardness value of Mg-2Zn-0.2Mn-xCa alloy has increased from 47.54 HV to 61.00 HV.Three different Ca content samples of Mg-2Zn-0.2Mn-xCa alloy were analyzed and tested by hydrogen evolution experiment,while the result indicates,with the increase of Ca content the average hydrogen evolution of alloy takes the trend of decreasing first and increasing second.When the Ca content is 0.4%,the alloy has the lowest average hydrogen evolution rate of 2.588ml/cm2/Day;and when the Ca content is 0.7%,the alloy has the highest average hydrogen content ofml/cm2/Day。The effects of heat treatment on the corrosion rate of Mg-2Zn-0.2Mn-0.1Ca,Mg-2Zn-0.2Mn-0.4Ca alloy have been studied.The result shows that the average hydrogen evolution of the two alloys decreases with the increase of heat treatment temperature.The average hydrogen evolution amount of Mg-2Zn-0.2Mn-0.1Ca alloy after heat treatment at 380°C and 420°C is 2.124ml/cm2/Day,and 1.538ml/cm2/Day,the relative as-casts were reduced by 28.76% and 43.77% respectively.Moreover,the average hydrogen evolution amount of Mg-2Zn-0.2Mn-0.4Ca alloy after heat treatment at 380°C and 420°C is1.489ml/cm2/Day,and 1.291ml/cm2/Day,relative to the as-cast were reduced by 42.49%,and 50.14% each.更多还原