Strain softening and microstructural evolution of anorthite aggregates and quartz-anorthite layered composites deformed in torsion

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	Strain softening and microstructural evolution of anorthite aggregates and quartz-anorthite layered composites deformed in torsion
	Ji, SC ; Jiang, ZT ; Rybacki, E ; Wirth, R ; Prior, D ; Xia, B
刊名	EARTH AND PLANETARY SCIENCE LETTERS
	2004
卷号	222 期号:2 页码:377-390
关键词	anorthite quartz-anorthite composite simple shear crystallographic preferred orientation flow strength
ISSN号	0012-821X
通讯作者	sji@polymtl.ca
中文摘要	Torsion experiments of anorthite (An) aggregates and layered composites with equal volume fractions of quartz (Qtz) and An were performed in a gas-medium apparatus at a confining pressure of 400 MPa, temperatures from 1373 to 1473 K, and twist rates from 1.0 x 10(-4) to 3.0 x 10(-4) rad/s. Dense specimens were fabricated from An glass and Qtz crystalline powder using hot isostatic pressing (HIP) techniques. Both An aggregates and Qtz-An layered composites show a continuous strain weakening from a peak stress at gamma=0.2-0.3 to gamma=3.2, and steady-state flow has not reached under the experimental conditions. The weakening is even more pronounced in the layered composites than the monolithic aggregates, suggesting channeling or localization of flow into the weak material between strong layers. The sheared An specimens developed pervasively C-S-C' structures which are similar to those observed in natural ductile shear zones. TEM and electron backscattering diffraction (EBSD) fabric analyses suggest that grain boundary migration recrystallization-accommodated dislocation creep with (010)[100] as the dominant slip system was operating in the An. The strain softening may be due to the development of crystallographic preferred orientation (CPO), the operation of dynamic recrystallization and the formation of extremely fine-grained recrystallized material in the narrow C' shear bands. (C) 2004 Elsevier B.V All rights reserved.
学科主题	Geochemistry & Geophysics
收录类别	SCI
原文出处	ELSEVIER SCIENCE BV
WOS记录号	WOS:000221993700004
公开日期	2011-07-03
内容类型	期刊论文
源URL	[http://ir.scsio.ac.cn/handle/344004/4802]
专题	南海海洋研究所_中科院边缘海地质重点实验室
推荐引用方式 GB/T 7714	Ji, SC,Jiang, ZT,Rybacki, E,et al. Strain softening and microstructural evolution of anorthite aggregates and quartz-anorthite layered composites deformed in torsion[J]. EARTH AND PLANETARY SCIENCE LETTERS,2004,222(2):377-390.
APA	Ji, SC,Jiang, ZT,Rybacki, E,Wirth, R,Prior, D,&Xia, B.(2004).Strain softening and microstructural evolution of anorthite aggregates and quartz-anorthite layered composites deformed in torsion.EARTH AND PLANETARY SCIENCE LETTERS,222(2),377-390.
MLA	Ji, SC,et al."Strain softening and microstructural evolution of anorthite aggregates and quartz-anorthite layered composites deformed in torsion".EARTH AND PLANETARY SCIENCE LETTERS 222.2(2004):377-390.