DOI: 10.1002/2017JF004335
Scopus记录号: 2-s2.0-85043698472
论文题名: The Effects of H2SO4 on the Mechanical Behavior and Microstructural Evolution of Polycrystalline Ice
作者: Hammonds K. ; Baker I.
刊名: Journal of Geophysical Research: Earth Surface
ISSN: 21699003
出版年: 2018
卷: 123, 期: 3 起始页码: 535
结束页码: 556
语种: 英语
英文关键词: glaciers
; ice
; ice sheets
; Raman spectroscopy
; rheology
; sulfuric acid
Scopus关键词: glacier
; ice sheet
; mechanical property
; microstructure
; Raman spectroscopy
; rheology
; sulfate
; sulfuric acid
英文摘要: The Earth's large continental ice sheets contain a variety of naturally occurring impurities, both soluble and insoluble. Understanding how these impurities affect the rheology, intrinsic thermodynamic properties, and fate of these ice sheets is not well understood. To investigate the effects that trace amounts of H2SO4 have on the flow and ductility of polycrystalline ice, a series of mechanical tests were conducted at −6, −10, −12.5, and −20°C using laboratory-prepared specimens of polycrystalline ice doped with 1–15 ppm of H2SO4. Parallel tests were performed on identical but undoped specimens of polycrystalline ice. Mechanical testing included constant-load tensile creep tests at an initial stress of 0.75 MPa and compression tests at constant displacement rates with initial strain rates ranging from 1 × 10−6 to 1 × 10−4 s−1. It was found that H2SO4-doped specimens of ice exhibited faster creep rates in tension and significantly lower peak stresses in compression, when compared to the undoped ice. Postmortem microstructural analyses were performed using cross-polarized light thin section imaging, X-ray computed microtomography, Raman spectroscopy, and electron backscatter diffraction. These analyses showed that H2SO4-doped specimens had a larger grain size at strains ≤15%, and an earlier onset of microcracking at lower strain rates than the undoped ice. Strain-induced grain boundary migration was found to be the predominant mechanism of recrystallization in both doped and undoped specimens. Further, an aqueous phase of H2SO4 was found to exist at the grain boundaries and triple junctions of the doped ice, which is thought to have significantly contributed toward its reduced viscosity. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114387
Appears in Collections: 气候减缓与适应
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作者单位: Department of Civil Engineering, Montana State University, Bozeman, MT, United States; Thayer School of Engineering, Dartmouth College, Hanover, NH, United States
Recommended Citation:
Hammonds K.,Baker I.. The Effects of H2SO4 on the Mechanical Behavior and Microstructural Evolution of Polycrystalline Ice[J]. Journal of Geophysical Research: Earth Surface,2018-01-01,123(3)