Effects of oxidizer and architecture on the thermochemical reactivity, laser ignition and combustion properties of nanothermite

Abstract

Energetic materials have been widely employed in both military and aerospace fields. Nanothermite has superior energy properties and better combustion performance compared with conventional organic energetic materials. In this paper, a novel nitrocellulose coated aluminum/copper ferrite (Al/CuFe2O4@NC) thermite composite with moderate energy release was assembled via electrospray. The intimate contact and uniform distribution between the fuel (Al) and oxidizer (CuFe2O4) are achieved in Al/CuFe2O4@NC microparticles. The thermochemical reactivity, laser ignition and combustion performance of Al/CuFe2O4@NC were investigated and compared with those of Al/CuO@NC, Al/Fe2O3@NC and physical mixture of Al and CuFe2O4 (PM. Al + CuFe2O4). The thermite reaction of Al/CuFe2O4@NC composite is dominated by the solid–solid reaction, which is similar to that of Al/CuO@NC and Al/Fe2O3@NC. Al/CuFe2O4@NC composite show a short ignition delay time of ∼ 4.0 ms and a moderate combustion process. The burning rates of Al/CuFe2O4@NC can be adjusted in the range of ∼ 0.39–1.77 m·s−1 by varying the content of NC in composite. In addition, the pressurization characteristics and condensed combustion products of thermite composites with different oxidizers were also investigated. The results indicate that the oxidizer and architecture have considerable effects on the thermochemical reactivity, laser ignition and combustion performance of thermite composite. The large heat release and superior ignition and combustion performance can be achieved by electrospray technology, which is an effective approach for enhancing interfacial contact.