Reaction characteristics and iron aluminides products analysis of planar interfacial Al/α-Fe2O3 nanolaminate

Abstract

Compared with organic-counterpart or micro-counterpart, nanothermites have attracted substantial interests owing to their exhibited outstanding properties. A common goal of a great amount of studies in nanothermite-based energetic materials is to enhance the reaction properties. Thermite planar geometry structural systems have been the promising structures because they are very tunable to control the alternating layered geometry and thickness of fuel and oxidizer. In this article, the planar interfacial contact Al/Fe2O3 nanolaminate thermite systems were studied to explore the effects of variations in preheating temperature, preheating rate and the initial distance between participating fuel and oxidizer on reaction properties and products characterizations by using the classic molecular dynamics simulations. According to the results, ignition delay and reaction time decrease with increasing the preheating temperature. The ignition delay and reaction time decrease from hundreds of picoseconds to a few tens of picoseconds. Additionally, higher heating rate results in higher energized structure, and much more energy was absorbed during heating period leading to a much shorter ignition delay. Reaction will start when the initial distance among reactants is shorter than a certain distance after passing through the ignition delay. Analyses also show the majority number of triangular structure for Fe2Al clusters and a small amount of tetrahedral structure for Fe3Al clusters during thermite reaction.