新型可降解生物医用Zn-Sn及Zn-Zr合金的组织及性能研究

发布时间：2017-12-31 15:38

本文关键词：新型可降解生物医用Zn-Sn及Zn-Zr合金的组织及性能研究　出处：《太原理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：基于良好生物相容性和力学性能,近二十年来可降解生物医用金属材料成为植入材料领域研究的热点。以镁及镁合金和铁及铁合金为代表进行了大量研究,但因前者降解速率过快、而后者降解速率过慢的问题制约其在临床上的应用。锌及其合金是近几年来被发现的一种新型生物可降解金属材料,且比镁耐腐蚀,比铁易腐蚀,可避免降解过快或者过慢引发的问题。但是,纯锌力学性能较差,无法满足植入体内材料所要求的力学性能,这是制约其发展的重要因素。为了改善纯锌的力学性能,本课题设计并采用热挤压成型工艺制备了Zn-Sn和Zn-Zr两种体系六种成分的新型生物锌合金。表征和分析了不同Sn、Zr含量对锌合金微观组织结构、物相成分、显微硬度、拉伸性能等的影响规律;对比了两种体系合金的降解过程和腐蚀机理,并对其生物相容性进行了评价。研究结果如下:挤压态Zn-Sn合金的成分分别为Zn-0.9Sn、Zn-1.4Sn和Zn-1.9Sn。ZnSn合金中的Zn和Sn并没有形成固溶体或者中间相,富锡相均匀分布于其基体中。Zn-Sn合金的拉伸强度、屈服强度和延伸率与纯锌相比均有了一定程度的改善,最大增幅分别达到21.3%、29.9%和68.6%。Zn-Sn合金的耐腐蚀性随着Sn含量的增加而提高,Zn-1.9Sn的耐蚀性最优,降解速率仅为0.08 mm/y。Zn-Sn合金的生物相容性评价表明其虽有良好的血液相容性,但细胞相容性并不理想,会产生细胞毒性。挤压态Zn-Zr合金的成分分别为Zn-0.5Zr、Zn-0.8Zr和Zn-1.1Zr。ZnZr合金中的Zn和Zr会形成中间相Zn2Zr,其主要存在于富锆相中。Zn-Zr合金的拉伸强度、屈服强度和延伸率比纯锌分别提高了69.9%、54.6%和19.6%。Zn-Zr合金的耐蚀性会随着Zr含量的增加而增强,Zn-1.1Zr和Zn-0.8Zr的耐蚀性相对较好。与Zn-Sn合金对比,Zn-Zr合金具有更加优良的血液相容性和细胞相容性,细胞毒性实验结果也表明其对细胞无毒性,甚至会促进细胞的生长增殖。综合对比各项性能,Zn-Zr合金的性能明显优于Zn-Sn合金。Zn-Zr合金的力学性能、降解速率和生物相容性均符合可降解生物医用金属材料的要求,其中Zn-0.8Zr各项指标优异,是最佳的可降解生物锌合金材料。
[Abstract]:Based on good biocompatibility and mechanical properties, biodegradable biomedical metal materials have become a hot spot in the field of implant materials in the past two decades. A large number of researches have been carried out on magnesium and magnesium alloys and iron and ferroalloys. However, the former degradation rate is too fast, while the latter degradation rate is too slow to restrict its clinical application. Zinc and its alloys are a new biodegradable metal material found in recent years, and are more resistant to corrosion than magnesium. Iron is more susceptible to corrosion and can avoid the problems caused by too fast or too slow degradation. However, the mechanical properties of pure zinc are poor and can not meet the mechanical properties required by implanted materials. In order to improve the mechanical properties of pure zinc, this is an important factor restricting its development. In this paper, a new type of zinc alloy with six components in Zn-Sn and Zn-Zr systems was designed and prepared by hot extrusion process. Different Sn was characterized and analyzed. The effect of Zr content on microstructure, phase composition, microhardness and tensile properties of zinc alloy; The degradation process and corrosion mechanism of the two alloys were compared and their biocompatibility was evaluated. The results are as follows: the composition of extruded Zn-Sn alloy is Zn-0.9Sn respectively. Zn and Sn in Zn-1.4Sn and Zn-1.9Sn.ZnSn alloys do not form solid solution or mesophase. Compared with pure zinc, the tensile strength, yield strength and elongation of the rich tin phase distributed uniformly in the matrix of. Zn-Sn alloy were improved to a certain extent, with the maximum increase of 21.3%, respectively. The corrosion resistance of 29.9% and 68.6% Zn-Sn alloy increases with the increase of Sn content, and the corrosion resistance of Zn-1.9 Sn alloy is optimized. Biocompatibility evaluation of 0.08 mm/y.Zn-Sn alloy showed that it had good blood compatibility, but its cytocompatibility was not ideal. The components of the extruded Zn-Zr alloy are Zn-0.5Zr respectively. Zn and Zr in Zn-0.8Zr and Zn-1.1Zr.ZnZr alloys form mesophase Zn2Zr.The tensile strength of Zn-Zr alloy mainly exists in Zirconium rich phase. Compared with pure zinc, the yield strength and elongation increased by 69.9% and 19.6%, respectively. The corrosion resistance of Zn-Zr alloy increased with the increase of Zr content. The corrosion resistance of Zn-1.1Zr and Zn-0.8Zr is relatively good. Compared with Zn-Sn alloy, Zn-Zr alloy has better blood compatibility and cell compatibility. Cytotoxicity test results also show that it is not toxic to cells, and even promote the growth and proliferation of cells. The mechanical properties of Zn-Zr alloy are obviously better than those of Zn-Sn alloy. Zn-Zr alloy. The degradation rate and biocompatibility of Zn-Zr alloy meet the requirements of biodegradable biomedical metal materials. Zn-0.8Zr is the best biodegradable biodegradable zinc alloy because of its excellent properties.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG146.13;R318.08

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