Metal-fluorocarbon pyrolants. XIII: High performance infrared decoy flare compositions based on MgB2 and Mg2Si and Polytetrafluoroethylene/Viton®

In the presented work two experimental pyrolants for use in blackbody infrared decoy flares showing higher performance than baseline magnesium/polytetrafluoroethylene/Viton (R) (MTV) were investigated. These pyrolants are based on fuels hitherto unknown to pyrotechnics: magnesium diboride, MgB2, and dimagnesium silicide, Mg2Si. Both fuels were formulated with polytetrafluoroethylene, PTFE and a fluorocarbon binder Viton (R) (designated MbTV and MsTV). MsTV yields higher radiance, L? (W?cm-2?sr-1) in the mid infrared range (25 mu m) than MTV at same stoichiometry. The volumetric spectral efficiency E? (J?cm-3?sr-1) of MbTV is also superior to MTV. MbTV thus allows for size reduction of black body countermeasure flares and thereby has potential to enhance the survivability of aircraft in hostile environments. Due to its very high burning rate MsTV qualifies for first fire and igniter applications

Study of Basic Oxidation and Combustion Characteristics of Aluminum Nanoparticles under Enginelike Conditions

[EN] The prominent aim of this investigation was the examination of the in-principle easibility of aluminum combustion under internal combustion engine (ICE)-like conditions. This study was performed in the framework of recent consideration of metallic nanoparticles as alternative fuels for ICE engines. Aluminum nanoparticles of different morphologies and sizes were studied with respect to their fundamental oxidation characteristics via thermogravimetric analysis under various nitrogen−oxygen environments and by spark-ignition of Al nanopowder strips under controlled airflow at ambient pressure. The ICE-like tests included measurements performed in two different arrangements; namely, a shock-tube setup and a constantvolume combustion vessel. A set of engine tests was also performed in a single-cylinder compression-ignition engine with a customized, single-shot aerosol injection system. Burned powder samples were, in all cases, examined via in situ and ex situ techniques for the identification of products and their morphologies. The results largely verified that combustion of aluminum particles in an engine environment is indeed feasible. Nonetheless, prominent differences, in terms of the products formed and their morphologies/structures, were identified among the various oxidation/combustion techniques employed.We thank the European Commission for partially funding of this work through the Project "COMETNANO" (FP7-NMP4-SL-2009-229063).Mandilas, C.; Karagiannakis, G.; Konstandopoulos, A.; Beatrice, C.; Lazzaro, M.; Di Blasio, G.; Molina, S.... (2014). Study of Basic Oxidation and Combustion Characteristics of Aluminum Nanoparticles under Enginelike Conditions. Energy and Fuels. 28(5):3430-3441. https://doi.org/10.1021/ef5001369S3430344128