Results 131 to 140 of about 639 (160)

Propellants Reactivity Enhancement with Nanothermites

Propellants, Explosives, Pyrotechnics, 2016
AbstractPropellant grains (Vectan A1) were coated with a thin and stable layer (50 μm, 10 wt‐%) of a “green” sulfate‐based nanothermite (Na2SO4/Al). This flash composition was used herein as an internal pyrotechnic lighter to accelerate the ignition and the combustion of the propellant. The combustion of the modified propellant, which was tested in one‐
Jean‐Edouard Berthe, Marc Comet, Fabien Schnell, Yves Suma, Denis Spitzer   +4 more
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Nanothermite foams: From nanopowder to object

Chemical Engineering Journal, 2017
Abstract Nanothermites are combustible mixtures made up of a metallic oxide and a reducing metal. The high combustion velocities of nanothermite loose powders (0.1–2.5 km/s) arise from the propagation of heat through their porosity by the advection of hot gases and particles.
Marc Comet, Cédric Martin, Fabien Schnell, Denis Spitzer   +3 more
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Les nanothermites

2016
L’introduction récente de la dimension « nano » dans le domaine de la pyrotechnie a permis de développer une nouvelle famille de substances hautement réactives : les nanothermites. Celles-ci ont une composition chimique comparable à celle des thermites de granulométrie submillimétrique ou micrométrique, mais possèdent une morphologie ayant un degré d ...
Eric Lafontaine, Marc Comet
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Nanothermites for space and defence applications

SPIE Proceedings, 2009
Thermites are energetic materials which are made of a metallic oxide mixed with a reducing metal1. The reactivity of classical thermites is moderate but it can be substantially improved when micron-sized particles are replaced by nanoparticles. In this paper, three examples of nanothermites are given in order to illustrate the contribution of these
Marc Comet, Denis Spitzer, Jean-Pierre Moeglin   +2 more
openaire   +1 more source

Fast-Impulse Nanothermite Solid-Propellant Miniaturized Thrusters

Journal of Propulsion and Power, 2013
Highly reactive nanothermites prepared by mixing bismuth trioxide or cupric oxide nanoparticles with aluminum nanoparticles were evaluated as solid propellants for small-scale propulsion applications. Miniaturized engines were fabricated from steel in three-piece configurations without a converging/diverging nozzle.
Clay S. Staley, Kristofer E. Raymond, Rajagopalan Thiruvengadathan, Steven J. Apperson, Keshab Gangopadhyay, Sean M. Swaszek, Robert J. Taylor, Shubhra Gangopadhyay   +7 more
openaire   +1 more source

Combustion Features of Nanothermites in Pyrotechnic Heaters

Russian Journal of Physical Chemistry B, 2019
Several thermite systems (Al/Fe2O3 and Mg/Fe2O3) with promising applications in sealed pyrotechnic heat sources under space conditions have been reported earlier. Experiments have found excellent propagation of the combustion reaction of these thermites inside sealed steel tubes. Outer tube surfaces have been heated up to 700–1000°C.
K. A. Monogarov, D. B. Meerov, Yu. V. Frolov, A. N. Pivkina   +3 more
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Aluminum Hydride as a Fuel Supplement to Nanothermites

Journal of Propulsion and Power, 2014
PressurizationratesincreasebyafactorofabouttwowiththeadditionofAlH3,whereasburntubevelocitiesincrease by about 25%. The enhancement in pressurization rate appears to primarily be a result of the increased pressure associated with the AlH3 decomposition in the nanocomposite thermite system and an enhancement in convective heat transfer.
G. Young, K. Sullivan, N. Piekiel, M. R. Zachariah   +3 more
openaire   +1 more source

Preparation and characterization of n-Al/FeF3 nanothermite

Chemical Engineering Journal, 2018
Abstract A new type of nanothermite composed of n-Al (metal fuel) and FeF3 (oxidizer) was investigated in this paper. The thermal behavior and combustion properties of the n-Al/FeF3 nanothermite were compared with that of n-Al/Fe2O3 nanothermite by TG/DSC-MS, XRD, SEM and high-speed camera.
Pan Liu, Xiangyu Li, Long Cheng, Xuqiang Zhu, Yanchun Li, Dongming Song   +5 more
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Direct Writing of a 90 wt% Particle Loading Nanothermite

Advanced Materials, 2019
AbstractThe additive manufacturing of energetic materials has received worldwide attention. Here, an ink formulation is developed with only 10 wt% of polymers, which can bind a 90 wt% nanothermite using a simple direct‐writing approach. The key additive in the ink is a hybrid polymer of poly(vinylidene fluoride) (PVDF) and hydroxy propyl methyl ...
Haiyang Wang, Jinpeng Shen, Dylan J. Kline, Noah Eckman, Niti R. Agrawal, Tao Wu, Peng Wang, Michael R. Zachariah   +7 more
openaire   +2 more sources

Semi-Empirical Model for Reaction Progress in Nanothermite

Journal of Propulsion and Power, 2010
Calculations of thermite reaction progress were made using the Cheetah thermochemistry package. Progress was modeled by fractionally substituting reactants with an inert species with identical thermodynamic properties. The results of this model have been used to create a semi-empirical model of regression rate.
Adam Trebs, Timothy J. Foley
openaire   +1 more source