Microstructural study of IF-WS2 Failure Models
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Authors
Cook, Jamie
Rhyans, Steven
Roncase, Lou
Hobson, Garth
Luhrs, Claudia C.
Subjects
WS2
shock absorbing structures
fracture mechanism
shock absorbing structures
fracture mechanism
Advisors
Date of Issue
2014
Date
Publisher
Language
Abstract
This manuscript summarizes the failure mechanisms found in inorganic fullerene-type tungsten disulfide (IF-WS2) nanoparticles treated with diverse pressure loading methods. The approaches utilized to induce failure included: the use of an ultrasonic horn, the buildup of high pressures inside a shock tube which created a shock wave that propagated and impinged in the sample, and impact with military rounds. After treatment, samples were characterized using electron microscopy, powder X-ray diffraction, energy dispersive X-ray spectroscopy, and surface area analysis. The microstructural changes observed in the IF-WS2 particulates as a consequence of the treatments could be categorized in two distinct fracture modes. The most commonly observed was the formation of a crack at the particles surface followed by a phase transformation from the 3D cage-like structures into the 2D layered polymorphs, with subsequent agglomeration of the plate-like sheets to produce larger particle sizes. The secondary mechanism identified was the incipient delamination of IF-WS2. We encountered evidence that the IF-WS2 structure collapse initiated in all cases at the edges and vertices of the polyhedral particles, which acted as stress concentrators, independent of the load application mode or its duration.
Type
Article
Description
The article of record as published may be found at http://dx.doi.org/10.3390/inorganics2030377
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Department
Mechanical and Aerospace Engineering
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Citation
Inorganics, Volume 2, pp. 377-395, 2014
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This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.