Disparate micro-mechanical behaviors of adjacent bone lamellae through in situ SEM micropillar compression
Disparate micro-mechanical behaviors of adjacent bone lamellae through in situ SEM micropillar compression
复制标题
通过原位 SEM 微柱压缩观察相邻骨板的不同微机械行为
DOI：
10.1016/j.msea.2021.141903
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发表时间：
2021-08-14
期刊：
影响因子：
6.4
通讯作者：
Ren, Luquan
中科院分区：
文献类型：
--
作者：
Ma, Zhichao;Qiang, Zhenfeng;Ren, Luquan
单个骨的机械性能和各向异性归因于相邻骨板的微机械行为。微观结构-性能关系可以揭示板层骨微观失效机制的基础。为了定量评估单个骨内相邻骨板的微机械行为，在三个相邻板内制造了六个尺寸相似的微柱（直径分别为1075 nm、1091 nm、1215 nm、1086 nm、1113 nm和1092 nm，纵横比为2:1）以避免尺寸效应。原位扫描电子显微镜压缩实验直接揭示了间隔微柱的胶原原纤维取向依赖的相似微机械行为和相邻微柱的不同行为。几个间隔开的微柱表现出相似的性能，包括强度、延展性、应力波动幅度、各向异性变形行为、弹性恢复和部分脆性破坏模式。中心微柱表现出最低的强度、延展性和应力波动幅度，并伴有各向同性、轻微恢复行为和部分失效模式。提出了变形理论来解释胶原纤维取向对微柱微机械行为的影响。通过弯曲胶原原纤维和倾斜羟基磷灰石晶体的表征，验证了胶原原纤维的小取向角可以增强微柱的强度、延展性和应力波动幅度。
The mechanical properties and anisotropy of a single osteon are attributed to the micro-mechanical behaviors of adjacent bone lamellae. The microstructure-property relationships could reveal the basis of the micro failure mechanisms of lamellar bone. In order to quantitatively evaluate the micro-mechanical behaviors of adjacent bone lamellae inside a single osteon, six micropillars with similar sizes (diameters of 1075 nm, 1091 nm, 1215 nm, 1086 nm, 1113 nm and 1092 nm, aspect ratio of 2:1) inside three adjacent lamellae were fabricated to avoid a size effect. The in situ scanning electron microscopy compressive experiments directly revealed the collagen fibril orientation-dependent similar micro-mechanical behaviors of the spaced micropillars and the disparate behaviors of adjacent micropillars. A couple of spaced micropillars exhibited similar performances, including in relation to strength, ductility, stress fluctuation amplitude, anisotropic deformation behavior, elastic recovery, and partial brittle failure mode. The central micropillars exhibited the lowest strength, ductility, and stress fluctuation amplitude, accompanied by isotropic, slight recovery behaviors and a partial failure mode. A deformation theory was proposed to explain the effect of collagen fibril orientation on the micro-mechanical behaviors of micropillars. A small orientation angle of collagen fibrils was verified to enhance the strength, ductility, and stress fluctuation amplitude of micropillars through the characterization of bent collagen fibrils and oblique hydroxyapatite crystals.