@article{9854e7d9a5e04019a68aa4f116ce750c,
title = "4D micro-scale, phase-contrast X-ray imaging and computed tomography of HMX-based polymer-bonded explosives during thermal runaway",
abstract = "High-resolution synchrotron x-ray radiography with computed tomography is used to observe the evolution of porosity created by thermal exposure in two HMX-based polymer-bonded explosive compositions; LX-04 and BX-63. The measurements were made in situ, over an extended period of time, during which the samples were heated on a slow-rate thermal trajectory. The tests ended with thermal-runaway to ignition after which the samples were consumed by combustion. The primary means of damage appears to be from mechanical debonding of the HMX-binder interface with secondary contribution from chemical decomposition. Confinement and binder properties affect the amount of porosity and permeability that develops. Additionally, observations were made describing the emergence and structure of an internal ignition volume, the formation and transport of a pre-ignition melt layer, and how the early stages of combustion were affected by material morphology, mechanical confinement and melt. The contact angle between molten HMX and the fluoropolymer, Viton A, is also presented. For the first time we have time-resolved x-ray images of ignition in sufficient detail to verify the mechanism of cookoff in polymer-bonded explosive compositions.",
keywords = "Auto-ignition, Convective burn, Damage, Explosive behavior, Porosity, Radiography",
author = "Gary Parker and David Eastwood and Malte Storm and Kalpani Vitharana and Heatwole, \{Eric M.\} and Ian Lopez-Pulliam and Broilo, \{Robert M.\} and Dickson, \{Peter M.\} and Anna Martinez and Christoph Rau and Bourne, \{Neil K.\}",
note = "Funding Information: The authors thank Diamond Light Source for the award of beamtime (proposals MT15068, MT16650 and MT18198) and the staff of the Diamond Manchester beamline I13. We gratefully acknowledge additional funding from our sponsors and colleagues in the DOE Science Programs and the LANL NSR\&D Program. Specifically, thanks to Dana Dattelbaum, Scott Jackson, Tommy Morris, Paul Peterson, Tammy Diaz and Dan Borovina for their continuing support. Bryce Tappan provided helpful discussion and TGA data for binder decomposition; his chemistry expertise and willingness to help is appreciated. Explosive samples packaging and transport was arranged by colleagues at the UK Atomic Weapons Establishment; we thank Peter Bolton, Annette Glauser, Adam Hazelwood, Paul Ryan, Steve James and Steve Goveas for this important contribution. This work was performed under the auspices of the U.S. Department of Energy's National Nuclear Security Administration, at Los Alamos National Laboratory, managed by Triad, LLC. under contract 89233218CNA000001. Funding Information: The authors thank Diamond Light Source for the award of beamtime (proposals MT15068, MT16650 and MT18198) and the staff of the Diamond Manchester beamline I13. We gratefully acknowledge additional funding from our sponsors and colleagues in the DOE Science Programs and the LANL NSR\&D Program. Specifically, thanks to Dana Dattelbaum, Scott Jackson, Tommy Morris, Paul Peterson, Tammy Diaz and Dan Borovina for their continuing support. Bryce Tappan provided helpful discussion and TGA data for binder decomposition; his chemistry expertise and willingness to help is appreciated. Explosive samples packaging and transport was arranged by colleagues at the UK Atomic Weapons Establishment; we thank Peter Bolton, Annette Glauser, Adam Hazelwood, Paul Ryan, Steve James and Steve Goveas for this important contribution. This work was performed under the auspices of the U.S. Department of Energy{\textquoteright}s National Nuclear Security Administration, at Los Alamos National Laboratory, managed by Triad, LLC. under contract 89233218CNA000001. Publisher Copyright: {\textcopyright} 2020",
year = "2021",
month = jan,
day = "6",
doi = "10.1016/j.combustflame.2020.12.025",
language = "English",
volume = "226",
pages = "478--489",
journal = "Combustion and Flame",
issn = "0010-2180",
publisher = "Elsevier BV",
}