锶元素含量及其热处理工艺对医用可降解Mg-Zn-Zr-Sr合金性能的研究
发布时间：2018-08-09 07:06
【摘要】：根据可降解松质骨螺钉的服役环境,及其所处的位置特殊性,为了提高现有的生物医用镁合金材料的耐蚀性以及力学性能,我们选用了可降解镁合金来做骨螺钉。锶作为人体的必需微量元素,它具有防止动脉硬化以及血栓形成的功能,因此本文的实验内容是在本课题组研究的Mg-Zn-Zr合金上设计并制备不同Sr含量的Mg-Zn-Zr-Sr合金,并对其力学性能、耐腐蚀性以及细胞毒性进行对比,探究不同含量的Sr元素以及固溶与时效处理对镁合金综合性能的影响。本研究采用真空与惰性气体保护的方法熔炼了Mg-3.2Zn-0.8Zr-0.1Sr、Mg-3.2Zn-0.8Zr-0.3Sr及Mg-3.2Zn-0.8Zr-0.5Sr合金,然后对其经过300℃×13h均匀化退火,再将铸锭挤压成棒材并截取试样,用光学显微镜观察试样的金相组织,并测量其晶粒尺寸;通过X射线衍射仪分析Mg-3.2Zn-0.8Zr-0.1Sr、Mg-3.2Zn-0.8Zr-0.3Sr及Mg-3.2Zn-0.8Zr-0.5Sr合金的相组成。为了探究这三种合金的力学性能,将挤压好的棒材加工成一些拉伸试样对其进行拉伸实验;采用三电极法测量合金的极化曲线;之后再利用固溶处理和时效处理这两种热处理工艺,研究固溶与时效处理工艺对合金力学性能与腐蚀性能的影响;通过浸泡实验测出pH值、Mg离子浓度以及失重来研究镁合金在体外的降解速率;最后再通过细胞毒性实验来检测三种合金经过浸泡实验后,利用浸提液来检测其毒性。结果表明:1.Mg-3.2Zn-0.8Zr-0.3Sr相比于Mg-3.2Zn-0.8Zr-0.1Sr和Mg-3.2Zn-0.8Zr-0.5Sr合金其力学性能,耐腐蚀性以及生物相容性最好。2.将三种合金经过固溶处理和时效处理之后,对其力学性能和耐腐蚀性再一次进行对比,得知最适宜的热处理工艺为在300℃×13h均匀化退火后再进行400℃×2h的固溶处理,此时的力学性能与耐腐蚀性最好。3.通过浸泡实验,经过固溶处理的Mg-3.2Zn-0.8Zr-0.3Sr合金的p H值、Mg离子的浓度以及失重相比于挤压态的Mg-3.2Zn-0.8Zr-0.3Sr和时效处理的Mg-3.2Zn-0.8Zr-0.3Sr合金都是最低的,因此经过固溶处理之后的Mg-3.2Zn-0.8Zr-0.3Sr合金的耐腐蚀性最好。4.在细胞毒性实验中,Mg-3.2Zn-0.8Zr-0.3Sr合金所产生的细胞毒性最小。
[Abstract]:According to the service environment of degradable cancellous bone screw and its special position, in order to improve the corrosion resistance and mechanical properties of biomedical magnesium alloy, we chose degradable magnesium alloy as bone screw. Strontium, as a necessary trace element in human body, has the function of preventing arteriosclerosis and thrombosis. Therefore, the experimental content of this paper is to design and prepare Mg-Zn-Zr-Sr alloy with different Sr content on the Mg-Zn-Zr alloy studied by our research group and its mechanical properties. The corrosion resistance and cytotoxicity of magnesium alloys were compared to explore the effects of different contents of Sr and solution and aging treatment on the comprehensive properties of magnesium alloys. In this study, Mg-3.2Zn-0.8Zr-0.1SrPg-3.2Zn-0.8Zr-0.3Sr and Mg-3.2Zn-0.8Zr-0.5Sr alloys were melted by vacuum and inert gas protection. After homogenized annealing at 300 鈩，
本文编号：2173298
[Abstract]:According to the service environment of degradable cancellous bone screw and its special position, in order to improve the corrosion resistance and mechanical properties of biomedical magnesium alloy, we chose degradable magnesium alloy as bone screw. Strontium, as a necessary trace element in human body, has the function of preventing arteriosclerosis and thrombosis. Therefore, the experimental content of this paper is to design and prepare Mg-Zn-Zr-Sr alloy with different Sr content on the Mg-Zn-Zr alloy studied by our research group and its mechanical properties. The corrosion resistance and cytotoxicity of magnesium alloys were compared to explore the effects of different contents of Sr and solution and aging treatment on the comprehensive properties of magnesium alloys. In this study, Mg-3.2Zn-0.8Zr-0.1SrPg-3.2Zn-0.8Zr-0.3Sr and Mg-3.2Zn-0.8Zr-0.5Sr alloys were melted by vacuum and inert gas protection. After homogenized annealing at 300 鈩，
本文编号：2173298
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