Evaluation of strengthening mechanisms in calcite single crystals from mollusk shells
Evaluation of strengthening mechanisms in calcite single crystals from mollusk shells
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DOI：
10.1016/j.actbio.2012.09.030
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发表时间：
2013-02-01
影响因子：
9.7
通讯作者：
Estroff, Lara A.
中科院分区：
文献类型：
--
作者：
Kunitake, Miki E.;Mangano, Lauren M.;Estroff, Lara A.
生物成因的单晶方解石经常被报道比冰洲石形式的地质方解石更硬和更坚韧。然而，生物材料优越的上级力学性能的机械起源仍然存在争议。我们调查的硬度和模量的生物方解石从棱柱层的软体动物Atrina rigida相比，纯地质方解石，冰洲石。在{001}面上，发现生物成因方解石比地质方解石硬50-70%。这个范围是由于压头尖端方位角的变化导致硬度变化近似于20%（单位：A）。而冰洲石只有7%。较高的硬度和增加的各向异性的生物方解石可以解释为硬化机制的基础上受阻位错运动，而不是裂纹偏转。(C)2012 Acts Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Biogenic single-crystal calcite is often reported to be harder and tougher than geologic calcite in the form of Iceland spar. However, the mechanistic origins of the superior mechanical properties of the biogenic materials are still debated. We investigate the hardness and modulus of biogenic calcite from the prismatic layer of the mollusk Atrina rigida compared with a pure geologic calcite, Iceland spar. On the {001} face, biogenic calcite is found to be 50-70% harder than geologic calcite. This range is due to the fact that changes in azimuthal angle of the indenter tip lead to a hardness variation of similar to 20% in A. rigida but only similar to 7% in Iceland spar. The higher hardness and increased anisotropy of biogenic calcite could be accounted for by hardening mechanisms based on hindered dislocation motion rather than crack deflection. (C) 2012 Acts Materialia Inc. Published by Elsevier Ltd. All rights reserved.