Effects of Al+Fe2O3 nanothermite on kinetic triplets and characteristics of RDX: Experiment and simulation methods

Abstract

The main goal of this work is to replace lead azide with Al+Fe₂O₃+RDX nanocomposite in surface detonator owing to the high sensitivity of the lead azide. To this end, Fe₂O₃ nanorods are synthesized by the hydrothermal method and applied as a nanocatalyst in the thermal decomposition of RDX, as well as an oxidant in an Al-based nanothermite. The successful synthesis of Fe₂O₃ nanorods is confirmed through X-ray diffraction, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy results. Subsequently, the effects of Al+Fe₂O₃ nanothermite on RDX properties were studied using experiments, molecular dynamic simulations, and numerical methods. The kinetic triplets of the samples’ reaction were estimated from the isoconversional method, and the most suitable reaction models of the samples’ reaction were investigated by the Coats−Redfern and master-plot methods. The results indicated that the mechanism function of the pure RDX was changed by adding the Al+Fe₂O₃ nanothermite. It was demonstrated that the activation energy for the thermal decomposition of the Al+Fe₂O₃+RDX nanocomposite was lower than that of pure RDX, validated by molecular dynamic simulation. Moreover, the effect of self-heating on the course of dα/dt and α vs. T curves was investigated. The Al+Fe₂O₃+RDX nanocomposite used in the surface detonator indicates considerable potential for initiating the Nonel tubes due to its high heat release and low detonation velocity. Furthermore, the Jones-Wilkins-Lee parameters of the samples are estimated by optimization algorithms.