Experimental Study On Nano-indentation Of Micro-mechanical Properties Of Biological Calcite

After hundreds of millions of years of evolution,many biological materials in nature have excellent mechanical properties,biological hard tissue materials is particularly typical,domestic and foreign scholars on the shell,teeth,bones and other biological materials excellent performance of the mechanism to carry out a lot of research.In the field of materials science,there are many new materials from the structural design inspiration from the biological hard tissue,so from the biological materials to study the reasons for its excellent mechanical properties of the design and preparation of new materials has profound significance.Shells and other excellent mechanical properties of biological hard tissue excellent performance of the genesis and mechanism,has been a hot topic of academic research,along with its organizational structure in-depth study,shellfish bionic material also came into being.In the preparation of materials encountered problems,from the shell mechanical properties of the study as a starting point,is a very effective means.Based on the analysis of the present situation of research and development in related fields at home and abroad,this paper studies the microstructure test and nanoindentation analysis of pearl mother in oyster shell to study the intrinsic mechanism of its excellent mechanical properties.In this paper,the main research and analysis methods of mechanical properties of materials and the research on the mechanical properties of biological tissue are reviewed and analyzed.The micro-mechanical properties of the pearl-shell structure in oyster shells are analyzed by nanoindentation test.And studied the preparation of material samples to solve the problem.First,this paper has developed a detailed route to explore the toughening mechanism of bio-calcite,and the mechanical properties of bio-calcite and mineral calcite are measured by nanoindentation test.The main mechanical parameters of the material are calculated by the corresponding analytical method.Mineral calcite two kinds of materials in the mechanical properties of the pros and cons.Then,the main crystal structure of pearl mother layer in oyster was determined by XRD analysis of pearl mother layer,mineral calcite and mineral calcitepowder in oyster.In this paper,nanoindentation analysis of bio-calcite was carried out.The micro-morphology of indentation micro-area was observed by scanning electron microscopy,and the mechanical response of nano-indentation of biogenic calcite and mineral calcite was compared.On the basis of the above work,the paper analyzes the organic matter composition and content of oyster pearl mother layer,and quantitatively analyzes the effect of organic matter in bio-calcite.Then,the force-thermal coupling experiment is carried out to explore the extreme temperature,The calculus of bio-calcite at different temperatures,the energy dissipation rate of the above materials was compared.The residual morphology of the calcite was observed after the low temperature indentation experiment.The effect of temperature effect on the mechanical response of nano-indentation of bio-calcite was analyzed.And the microscopic morphology of the chalk layer and the stratum corneum in the oyster shell were observed.