胫骨生物复合材料多级微纳米结构的韧性机理

Toughness mechanism of hierarchical micro-nanostructures from shankbone biocomposite

目的研究胫骨生物复合材料多级优良微纳米结构的韧性机理。方法利用扫描电镜观察胫骨成骨的多级微纳米结构。通过多级微纳米结构模型分析揭示胫骨的韧性机理。结果胫骨是一种由羟基磷灰石和胶原蛋白组成的、具有多级微纳米结构的生物复合材料。在不同尺度下的微纳米结构模型分析表明胫骨多层微纳米结构增加了胫骨的断裂能,而羟基磷灰石纤维片的交叉微结构以及羟基磷灰石纳米纤维片的长细形状尺寸增加了纤维片的拔出能。结论胫骨多级优良微纳米结构赋予胫骨高的断裂韧性,可用于仿生复合材料设计。

Objective To Investigate the toughness mechanism of the hierarchical and eximious micro-nanostructures from shankbone biocomposite.Methods The hierarchical micro-nanostructures of a mature shankbone were observed with a scanning electronic microscope and then to explore the toughness mechanism of this shankbone by the analyses on the models with hierarchical micro-nanostructures.Results The shankbone was made from a kind of biocomposite with hierarchical micro-nanostructures,consisting of hydroxyapatite and collagen protein matters.The micro-nanostructural model analyses at different scales indicated that the multilayer microstructure of the bone increased its fracture energy and the crossed microstructure of the hydroxyapatite fiber sheets as well as its long and thin shape size enhanced the maximum pullout energy of the fiber sheets.Conclusions The hierarchical and eximious micro-nanostructures in the bone endow the shankbone with high fracture toughness,and can be applied to the design of biomimetic composites.