【摘要】 天然生物材料的组织结构特征及其与性能间的关系研究对于材料的仿生设计有重要意义.利用压痕法压研究了贝壳材料的硬度,断裂韧性及脆性指标,并结合SEM技术研究了贝壳珍珠层压痕形貌,探讨了珍珠层的增韧机制.结果表明,无论是珍珠层和还是柱状晶生长纹对其性能影响较小,珍珠层在平行于片层方向上与垂直于片层方向的性能差别较大,珍珠层明显的各向异性主要来自于其独特的组织特征.珍珠层其成分和独特的微观结构特点决定了其在应力场中是一种能量耗散结构,裂纹在扩展过程中,裂纹偏转,有机物桥联,纤维拔出等多种增韧机制在协同作用于材料韧性.更多还原

【Abstract】 Microstructure of nacre is significant to understanding the behavior of nacre and the biomimetic designing of materials.The hardness,toughness and brittleness of nacre of bivalve shell is investigated.It is shown that the growing trace is not very significant to their properties of nacre and columnar crystal.But hardnesses of nacre in parallel and oblique directions with respect to tablet are different obviously because of its unique microstructure.The scanning election microscope observations of indentation in the nacre have been carried out.The results show several toughening mechanisms,such as crack deflection,fiber pullout,organic matrix bridging in the nacre simultaneously,attribute to its unique microstructure.更多还原