Human tooth enamel is a natural biocomposite consisting of mineral units surrounded by a soft protein shell. The mechanical behaviors of enamel are closely associated with its structure. In this paper, the strain-rate dependent mechanical properties of enamel were investigated with nanoindentation techniques. Five constant strain rates (0.01 s⁻¹, 0.03 s⁻¹, 0.05 s⁻¹, 0.1 s⁻¹, 0.3 s⁻¹) were used in this study. Results showed that the hardness and elastic modulus of enamel increased with increasing strain rate. These results indicate that the variation of hardness under different stain rates is associated with creep behavior of organic matrix in enamel. And indentation creep rate sensitivity of human enamel was measured with a value of 0.062. Moreover, the elastic module of enamel is dependent upon strain rate. Such rate dependence originates from the organic matrix which is sensitive to the strain rate. This behavior may be important in explaining the excellent toughness and energy absorption abilities of natural tooth structure.

人牙釉质是一种天然生物复合材料，由被软蛋白壳包围的矿物质单元组成。搪瓷的机械性能与其结构密切相关。在本文中，使用纳米压痕技术研究了搪瓷的应变率依赖性机械性能。五个恒定应变速率（0.01秒^-1，0.03小号^-1，0.05秒^-1，0.1秒^-1，0.3秒^-1）用于本研究。结果表明，搪瓷的硬度和弹性模量随应变率的增加而增加。这些结果表明，在不同染色速率下硬度的变化与搪瓷中有机基质的蠕变行为有关。并且测得的人类牙釉质的压痕蠕变速率敏感性为0.062。此外，搪瓷的弹性模量取决于应变率。这种速率依赖性源自对应变速率敏感的有机基质。这种行为对于解释天然牙齿结构的出色韧性和能量吸收能力可能很重要。