生物方解石微观力学性能的纳米压痕试验研究

发布时间：2018-03-11 07:48

本文选题：生物方解石　切入点：珍珠母　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：经过亿万年的进化,自然界中很多生物材料具有优异的力学性能,生物硬组织材料尤为典型,国内外学者对贝壳、牙齿、骨骼等生物材料优异性能的机制开展了大量研究。在材料科学领域,有很多新材料的结构设计灵感源于生物硬组织,所以从生物材料入手,研究其优异力学性能的原因对新材料的设计制备具有深刻意义。贝壳等具有优异力学性能的生物硬组织优异性能的成因与机理,一直是学界研究的热点,伴随着对其组织结构深入研究,类贝壳仿生材料也应运而生。在材料制备遇到问题时,从贝壳力学性能的研究作为切入点,是十分有效的手段。本文在对国内外相关领域研究发展现状进行综述分析的基础上,针对牡蛎壳中珍珠母结构开展了微观组织结构测试与纳米压痕试验分析的研究,以研究其优异力学性能的内在机制。论文首先对材料力学性能主要测试分析手段和生物组织力学性能研究等国内外发展现状进行了综述分析,进而明确了采用纳米压痕测试技术研究开展牡蛎壳中珍珠母结构的微观力学性能测试分析,并研究解决了材料样品的制备问题。本文制定了探寻生物方解石增韧机制的详细路线,采用纳米压痕测试技术测定了生物方解石与矿物方解石的力学性能,并通过相应分析方法计算出材料的主要力学参数,对比了生物方解石与矿物方解石两种材料在力学性能上的优劣。随后针对珍珠母层、矿物方解石、矿物方解石粉末的XRD分析,明确了牡蛎中珍珠母层的主要晶体结构。本文在开展生物方解石纳米压痕测试分析的同时,还采用扫描电子显微镜观测了压痕微区的微观形貌,对比生物方解石与矿物方解石的纳米压痕力学响应。在上述工作的基础上,论文针对牡蛎珍珠母层中的有机质成分及含量进行了测定分析,定量分析了有机质在生物方解石中的作用。随后,本文进行了力-热耦合实验,探究极端温度下,生物方解石的力学响应,不同温度下生物方解石的蠕变现象,对比了上述材料的能量耗散率,观测了生物方解石进行低温压痕实验后的残余形貌,分析了温度效应对生物方解石纳米压痕力学响应的影响,同时观测了牡蛎壳中白垩层与角质层的的微观形貌。
[Abstract]:After billions of years of evolution, many biomaterials in nature have excellent mechanical properties, especially biomaterials of hard tissue, domestic and foreign scholars on shells, teeth, The mechanism of excellent performance of biomaterials such as bone has been studied extensively. In the field of material science, many new materials have their structural design inspiration from biological hard tissue, so they start with biomaterials. It is of great significance for the design and preparation of new materials to study the reasons for their excellent mechanical properties. The origin and mechanism of the excellent properties of biological hard tissues with excellent mechanical properties such as shells have always been the focus of academic research. Along with the in-depth study of its structure, shell-like biomimetic materials also came into being. When the preparation of the materials encountered problems, the research of shell mechanical properties was taken as the breakthrough point. In this paper, based on the review and analysis of the current situation of research and development in related fields at home and abroad, the microstructure of pearl mother structure in oyster shell and the analysis of nano-indentation test were carried out. In order to study the internal mechanism of its excellent mechanical properties, this paper firstly summarizes and analyzes the main methods of testing and analyzing the mechanical properties of materials and the research of biomechanical properties of biological tissues at home and abroad. Furthermore, the micromechanical properties of pearl mother structure in oyster shell were tested and analyzed by using nano-indentation test technique. In this paper, a detailed route to explore the toughening mechanism of biogenic calcite was established, and the mechanical properties of biogenic calcite and mineral calcite were measured by nano-indentation test technique. The main mechanical parameters of the material are calculated by the corresponding analysis method, and the mechanical properties of the biological calcite and the mineral calcite are compared. Then, the XRD analysis of the pearl matrix, mineral calcite and mineral calcite powder is carried out. The main crystal structure of pearl parent layer in oyster was clarified. The micromorphology of indentation microregion was observed by scanning electron microscope (SEM), while the nano-indentation test of biogenic calcite was carried out. The mechanical response of nano-indentation of biogenic calcite and mineral calcite was compared. Based on the above work, the composition and content of organic matter in oyster pearl parent layer were determined and analyzed. The role of organic matter in biogenic calcite was analyzed quantitatively. Then, the mechanical-thermal coupling experiment was carried out to explore the mechanical response of biogenic calcite at extreme temperature and creep phenomenon of biogenic calcite at different temperatures. The energy dissipation rate of the above materials was compared, and the residual morphology of biological calcite after low temperature indentation experiment was observed, and the effect of temperature on the mechanical response of biocalcite nano-indentation was analyzed. At the same time, the micromorphology of chalk and cuticle in oyster shell was observed.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB301

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