黑色鳃金龟鞘翅微结构及其纳米力学性能

Micro structures and nano mechanical properties of beetle Sophrops elytra

利用扫描电镜观测了黑色鳃金龟鞘翅的微结构,借助纳米压痕仪测试并分析了鞘翅材料的纳米力学性能.SEM表明:黑色鳃金龟鞘翅采用了由背壁层、中空芯层和腹壁层构成的中空夹芯层复合结构,在满足鞘翅强度的同时保证了鞘翅对轻质的要求;微观尺度下鞘翅表面呈现非光滑表面织构.纳米压痕试验测得鞘翅外表皮的硬度为0.48 GPa,弹性模量为8.81 GPa,鞘翅的比刚度和比模量分别为600 MPa.(g.cm-3)-1和1.1×104MPa.(g.cm-3)-1.鞘翅接触刚度为(2.28±0.16)×104N.m-1,表明鞘翅有很好的抵抗变形的能力.鞘翅纳米力学性能呈现各向异性,靠近鞘翅对接缝处最大,鞘翅外边缘区域最小,且由鞘翅头部至鞘翅尾部区域有逐渐减小的趋势.

The micro structures of elytra were observed by scanning electron microscopy （SEM）, and the nano mechanical properties of elytra were determined and analyzed by nano indentation machine. The SEM images show that the elytra of Sophrops has empty laminate structure with dorsum, lumen and abdomen, which guarantees the light-weight characteristic of elytra with enough strength. On microscopic scale, the elytra shows non-smooth surface texture. The hardness and the modulus of elytra exocuticle by nano indentation tests are H of 0.48 GPa and Er of 5.51 GPa, respectively. The specific stiffness and the specific modulus are 600 MPa ·（g·cm^-3）^-1 and 1.1 × 10^4 MPa ·（g·cm^-3）^-1, respectively. The contact stiffness （K） of （2.28 ±0.16） ×10^4 N ·m^-1 indicates excellent capability of deforming resis- tance. The nano mechanical properties of elytra are anisotropic with the maximum near sutual edge and the minimum at verge zone. The mechanical properties decrease gradually from cephalosome zone to erapennage zone of elytra.