Study on Indium (III) Oxide/Aluminum Thermite Energetic Composites

Thermites or composite energetic materials are mixtures made of fuel and oxidizer particles at micron-scale. Thermite reactions are characterized by high adiabatic flame temperatures (>1000 °C) and high heats of reaction (>kJ/cm3), sometimes combined with gas generation. These properties strongly depend on the chemical nature of the couple of components implemented. The present work focuses on the use of indium (III) oxide nanoparticles as oxidizer in the elaboration of nanothermites. Mixed with an aluminum nanopowder, heat of reaction of the resulting Al/In2O3 energetic nanocomposite was calculated and its reactive performance (sensitivity thresholds regarding different stimuli (impact, friction, and electrostatic discharge) and combustion velocity examined. The Al/In2O3 nanothermite, whose heat of reaction was determined of about 11.75 kJ/cm3, was defined as insensitive and moderately sensitive to impact and friction stimuli and extreme sensitive to spark with values >100 N, 324 N, and 0.31 mJ, respectively. The spark sensitivity was decreased by increasing In2O3 oxidizer (27.71 mJ). The combustion speed in confined geometries experiments was established near 500 m/s. The nature of the oxidizer implemented herein within a thermite formulation is reported for the first time.

SPECTRAL STUDIES OF THE PROCESSES OF ALUMINUM NANOPOWDER FORMATION EXPOSING BY SHORT SERIES OF TWIN LASER PULSES IN THE AIR ATMOSPHERE

Проведено исследование процессов образования оксидированных нанопорошков Al в зависимости от количества импульсов при воздействии сдвоенных лазерных импульсов энергией 52 мДж и меж-импульсным интервалом 10 мкс на алюминиевую мишень, помещенную в закрытую стеклянную прямоугольную кювету. Установлено, что наибольшая интенсивность линий ионов Al(III) наблюдается при малом, порядка 15 импульсов, количестве последовательных сдвоенных импульсов в серии. Размер первичных частиц, оцененный с помощью электронной микроскопии высокого разрешения, преимущественно составил 50 - 60 нм, частицы собраны в агломераты. The processes of formation of oxidized nanopowders depending on the number of pulses were studied when double laser pulses with an energy of 52 mJ and an interpulse interval of 10 microseconds were applied to an aluminum target placed in a closed rectangular glass cuvette. It was found that the highest intensity of the Al III ion lines is observed at a small, about 15 pulses, consecutive double pulses in a series. The size of primary particles estimated by high-resolution electron microscopy was mainly 50 - 60 nm, and the particles were collected in agglomerates.