title: Microstructure and self-sharpening of the magnetite cap in chiton tooth.
abstract: The magnetite cap of chiton tooth (Acanthochiton rubrolineatus) was studied with SEM. Three microstructurally distinct regions were recognized: Region I, close to the anterior surface of the cusp and composed of thick rod microstructure units; Region III, close to the posterior surface and composed of fine fibers; and Region II, sandwiched between Regions I and II and composed of thin sheets. The microstructure units in the three regions constitute a continuous and integrated architecture component. The hardness of Regions I and II was measured to be Hv270 and Hv490, respectively. Based on these microstructure observation and hardness data, the abrasive behavior and microstructural mechanism of self-sharpening of the chiton tooth were discussed in the paper. The self-sharpening was attributed to the combined effect of the hardness and the texture orientation of the microstructure units in Regions I and II.
authors.affiliation: Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China.
authors.forename: C
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Aeronautics and Astronautics, Zhejiang University, Hangzhou 310027, China.
authors.forename: Q Y
authors.initials: QY
authors.lastname: Li
authors.affiliation: Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China.
authors.forename: S N
authors.initials: SN
authors.lastname: Wang
authors.affiliation: Department of Aeronautics and Astronautics, Zhejiang University, Hangzhou 310027, China.
authors.forename: S X
authors.initials: SX
authors.lastname: Qu
authors.affiliation: Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China. Electronic address: msewangxx@zju.edu.cn.
authors.forename: X X
authors.initials: XX
authors.lastname: Wang
mesh_terms: D000818:Animals; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D006244:Hardness; D008855:Microscopy, Electron, Scanning; D049916:Polyplacophora / Q000737:chemistry* / Q000378:metabolism; D014070:Tooth / Q000737:chemistry*
chemical_list: D052203:Ferrosoferric Oxide
keywords: Biomineral; Chiton; Magnetite; Self-sharpening; Tooth