Mechanical properties and atomistic deformation mechanism of gamma-Y(2)Si(2)O(7) from first-principles investigations

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	Mechanical properties and atomistic deformation mechanism of gamma-Y(2)Si(2)O(7) from first-principles investigations
	J. Y. Wang; Y. C. Zhou; Z. J. Lin
	2007
发表期刊	Acta Materialia
ISSN	1359-6454
卷号	55 期号:17 页码:6019-6026
摘要	The theoretical mechanical properties and atomistic shear deformation mechanisms Of gamma-Y(2)Si(2)O(7), one of the most refractory silicates and potentially useful as a high-temperature structural ceramic, were investigated using first-principles calculations. The material shows low shear moduli to bulk modulus ratios, as well as a low ideal shear strength to tensile strength ratio. The unusual low shear deformation resistance of gamma-Y(2)Si(2)O(7) originates from the inhomogeneous strength of its chemical bonds. The Y-O bond is weaker and readily stretches and shrinks; and Si-O bond is stronger and more rigid. The relative softer YO(6) octahedron positively accommodates shear deformation by structural distortion, while the Si(2)O(7) pyrosilicate unit is more resistant to deformation. The reported shear-load-bearing mechanism is quite similar to those found in the "quasi-ductile" LaPO(4) monazite and ternary layered carbides (the so-called MAX phases), and can endow gamma-Y(2)Si(2)O(7) with quasi-ductility and damage tolerance. (C) 2007 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
部门归属	chinese acad sci, met res inst, shenyang natl lab mat sci, shenyang 110016, peoples r china. natl inst mat sci, int ctr young scientists icys, tsukuba, ibaraki 3050044, japan. chinese acad sci, grad sch, beijing 100039, peoples r china.;wang, jy (reprint author), chinese acad sci, met res inst, shenyang natl lab mat sci, shenyang 110016, peoples r china;jywang@imr.ac.cn
关键词	Ceramics Elastic Behaviour Quasi-ductility First-principles Calculation Pressed Silicon-nitride Ternary Carbides Strength Disilicate Ceramics Behavior Diamond
URL	查看原文
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/33866
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	J. Y. Wang,Y. C. Zhou,Z. J. Lin. Mechanical properties and atomistic deformation mechanism of gamma-Y(2)Si(2)O(7) from first-principles investigations[J]. Acta Materialia,2007,55(17):6019-6026.
APA	J. Y. Wang,Y. C. Zhou,&Z. J. Lin.(2007).Mechanical properties and atomistic deformation mechanism of gamma-Y(2)Si(2)O(7) from first-principles investigations.Acta Materialia,55(17),6019-6026.
MLA	J. Y. Wang,et al."Mechanical properties and atomistic deformation mechanism of gamma-Y(2)Si(2)O(7) from first-principles investigations".Acta Materialia 55.17(2007):6019-6026.