CHARACTERISATION OF THE MULTI-LAYERED MICROSTRUCTURE OF CELLANA TESTUDINARIA SHELL USING ELECTRON BACKSCATTER DIFFRACTION (EBSD)

摘要

The microstructural and crystallographic aspect of hard tissues of natural shell samples plays an important role in the better understanding of the evolution of organisms. Seashells are organo-mineral composites of calcium carbonate (which accounts for 95 - 99 % in weight) and protein. The mineral fraction gives the shell stiffness, strength and hardness, whereas the organic fraction provides ductility, so that the final product has strength and toughness properties well above those of the individual components [1]. In limpets, as in most molluscs, the shell protects the animal from mechanical forces and serves to prevent dehydration during the periods when the limpet is exposed out of the water. The formation of such complex microstructures in the shell depends not on only inorganic reactions, but also the action of the organic matrices in the shell. Therefore, understanding the mechanisms of shell biomineralisation are the key factors for reconstructing such structures and for the production of synthetic structures with high strength and relatively low weight in the future.