The size effects of mechanical properties influence the microdeformation behaviors and failure mechanisms of hierarchical lamellar bones. Investigations of the continuous deformation behaviors and structure–behavior–property relationships of nanoscale lamellar bones provide essential data for reducing the risk of fracture. Here, five pillars with diameters ranging from 640 to 4971 nm inside a single lamella were fabricated. In situ pillar compressive tests inside a scanning electron microscope directly revealed the diameter-dependent enhanced strength, ductility, and stress fluctuation amplitude. Real-time observations also revealed the segmented deformation and morphological anisotropy of pillars with smaller diameters and the slight elastic recovery of pillars with larger diameters. The critical diameter leading to the brittle-to-ductile transition was confirmed. The “analogous to serrated flow” stress fluctuation behaviors at the nanoscale exhibited a significant size effect, with coincident fluctuation cycles independent of diameter, and each cycle of the fluctuation manifested as a slow stress increase and a rapid stress release. The discontinuous fracture of collagen fibrils, embedded enhancement of hydroxyapatite crystals, and layered dislocation movement on the basis of strain gradient plasticity theory were expected to induce cyclical stress fluctuations with different amplitudes.

力学性能的尺寸效应影响分层板层骨的微变形行为和破坏机制。对纳米级层状骨的连续变形行为和结构-行为-性能关系的研究为降低骨折风险提供了必要的数据。在这里，在单个薄片内制造了五个直径范围从 640 到 4971 nm 的柱子。扫描电子显微镜内的原位柱压缩测试直接揭示了与直径相关的增强强度、延展性和应力波动幅度。实时观测还揭示了直径较小的柱子的分段变形和形态各向异性，以及直径较大的柱子的轻微弹性恢复。确认了导致脆性到韧性转变的临界直径。在纳米尺度上“类似于锯齿流”的应力波动行为表现出显着的尺寸效应，具有与直径无关的重合波动周期，并且每个波动周期表现为缓慢的应力增加和快速的应力释放。胶原纤维的不连续断裂、羟基磷灰石晶体的嵌入增强以及基于应变梯度塑性理论的层状位错运动预计会引起不同幅度的周期性应力波动。而每一个周期的波动都表现为缓慢的应力增加和快速的应力释放。胶原纤维的不连续断裂、羟基磷灰石晶体的嵌入增强以及基于应变梯度塑性理论的层状位错运动预计会引起不同幅度的周期性应力波动。而每一个周期的波动都表现为缓慢的应力增加和快速的应力释放。胶原纤维的不连续断裂、羟基磷灰石晶体的嵌入增强以及基于应变梯度塑性理论的层状位错运动预计会引起不同幅度的周期性应力波动。