摘要:
以龟壳为对象,对其力学性能和显微结构进行了研究。不同的取样部位和加载方式,对抗弯强度有很大影响。抗弯强度最大值为165.1MPa,断裂韧性高达36.4MPa√m,龟壳由密质层和松质层组成。密质层的基本结构单元是Havevsian系统,在Havevsian系统的中央为Volkmann管,棒状羟磷灰石晶体沿Volkmann定向分布。而在松质层,长径比较大的棒状晶体聚集成束,呈无规则分布。棒状晶之间均由有机质膜相连。龟壳基板之间的接缝处,则是由大块片状羟磷灰石晶体组成,结构松散。
Abstract:
In the present paper,the mechanical properties and microstructure of a tortoise shell are studied.The flexural strength in the specimen varies with different parts and loading directions.The maximum flexural strength is 165.1MPa,and fracture toughness is 36.4MPa√m.The shell is comprised of base plates in a rectangle shape.The base plate includes a dense part and loose part.In the dense part,Harversian system is the basic structural unit.There exists Volkmann vessel at its center.The elongated Ca5(PO4)3(OH) crystals are orientationally arranged around the Volkmann vessel.In the loose part,several elongated crystals assemble together and disperse at random,of which the aspect ratio is greater than that in the dense part.There is an organic film between the crystals.The excellent toughness of the shell is attributed to the organic film between crystals and to the organic fibers in the volkmann vessel.
百度学术
下载:
