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Title: Phase stability of {epsilon} and {gamma} HNIW (CL-20) at high-pressure and temperature

Abstract

Hexanitrohexaazaisowurtzitane (CL-20) is one of the few ingredients developed since World War II to be considered for transition to military use. Five polymorphs have been identified for CL-20 by FTIR measurements ({alpha}, {beta}, {gamma}, {epsilon}, {zeta}). As CL-20 is transitioned into munitions it will become necessary to predict its response under conditions of detonation, for performance evaluation. Such predictive modeling requires a phase diagram and basic thermodynamic properties of the various phases at high pressure and temperature. Therefore, the epsilon and gamma phases of CL-20 at static high-pressure and temperature were investigated using synchrotron angle-dispersive x-ray diffraction experiments. The samples were compressed and heated using diamond anvil cells (DAC). Pressures and temperatures achieved were around 5 GPa and 240 deg. C, respectively. The epsilon phase was stable to 6.3 GPa at ambient temperature. When heated at ambient pressure the epsilon phase was sustained to a temperature of 120 deg. C then underwent a transition to the gamma phase above 125 deg. C and then thermal decomposition occurred above 150 deg. C. Upon compression, the gamma phase underwent a phase transition at both ambient temperature and 140 deg. C. Pressure--volume data for the epsilon and gamma phase at ambient temperature andmore » the epsilon phase at 75 deg. C were fit to the Birch-Murnaghan formalism to obtain isothermal equations of state.« less

Authors:
; ;  [1]
  1. Indian Head Division-Naval Surface Warfare Center, Indian Head, MD 20640 (United States)
Publication Date:
OSTI Identifier:
21039532
Resource Type:
Journal Article
Journal Name:
AIP Conference Proceedings
Additional Journal Information:
Journal Volume: 955; Journal Issue: 1; Conference: Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter, Waikoloa, HI (United States), 24-29 Jun 2007; Other Information: DOI: 10.1063/1.2832955; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-243X
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; AMBIENT TEMPERATURE; COMPRESSION; COMPUTERIZED SIMULATION; DIAMONDS; EQUATIONS OF STATE; EVALUATION; FOURIER TRANSFORMATION; INFRARED SPECTRA; ORGANIC COMPOUNDS; PERFORMANCE; PHASE DIAGRAMS; PHASE STABILITY; PHASE TRANSFORMATIONS; PRESSURE RANGE GIGA PA; PYROLYSIS; THERMODYNAMIC PROPERTIES; X-RAY DIFFRACTION

Citation Formats

Gump, Jared C, Stoltz, Chad A, and Peiris, Suhithi M. Phase stability of {epsilon} and {gamma} HNIW (CL-20) at high-pressure and temperature. United States: N. p., 2007. Web. doi:10.1063/1.2832955.
Gump, Jared C, Stoltz, Chad A, & Peiris, Suhithi M. Phase stability of {epsilon} and {gamma} HNIW (CL-20) at high-pressure and temperature. United States. doi:10.1063/1.2832955.
Gump, Jared C, Stoltz, Chad A, and Peiris, Suhithi M. Wed . "Phase stability of {epsilon} and {gamma} HNIW (CL-20) at high-pressure and temperature". United States. doi:10.1063/1.2832955.
@article{osti_21039532,
title = {Phase stability of {epsilon} and {gamma} HNIW (CL-20) at high-pressure and temperature},
author = {Gump, Jared C and Stoltz, Chad A and Peiris, Suhithi M},
abstractNote = {Hexanitrohexaazaisowurtzitane (CL-20) is one of the few ingredients developed since World War II to be considered for transition to military use. Five polymorphs have been identified for CL-20 by FTIR measurements ({alpha}, {beta}, {gamma}, {epsilon}, {zeta}). As CL-20 is transitioned into munitions it will become necessary to predict its response under conditions of detonation, for performance evaluation. Such predictive modeling requires a phase diagram and basic thermodynamic properties of the various phases at high pressure and temperature. Therefore, the epsilon and gamma phases of CL-20 at static high-pressure and temperature were investigated using synchrotron angle-dispersive x-ray diffraction experiments. The samples were compressed and heated using diamond anvil cells (DAC). Pressures and temperatures achieved were around 5 GPa and 240 deg. C, respectively. The epsilon phase was stable to 6.3 GPa at ambient temperature. When heated at ambient pressure the epsilon phase was sustained to a temperature of 120 deg. C then underwent a transition to the gamma phase above 125 deg. C and then thermal decomposition occurred above 150 deg. C. Upon compression, the gamma phase underwent a phase transition at both ambient temperature and 140 deg. C. Pressure--volume data for the epsilon and gamma phase at ambient temperature and the epsilon phase at 75 deg. C were fit to the Birch-Murnaghan formalism to obtain isothermal equations of state.},
doi = {10.1063/1.2832955},
journal = {AIP Conference Proceedings},
issn = {0094-243X},
number = 1,
volume = 955,
place = {United States},
year = {2007},
month = {12}
}