Exothermic reactions in Al–CuO nanocomposites

Formation of Cu layer on Al nanoparticles during thermite reaction in Al/CuO nanoparticle composites: Investigation of off-stoichiometry ratio of Al and CuO nanoparticles for maximum pressure change

“…We detected Al x Cu y alloys, Al 2 Cu and Al 4 Cu 9 , in XRD patterns. Although the stoichiometric thermite reaction does not involve the formation of such alloys, it has been reported that Al x Cu y may form via solid-state diffusion of Al and Cu at a temperature ranging between 550 and 1000 K [21] and at an elevated temperature in the case of Al/CuO composites [6,7]. Despite these observations, the effect of Al x Cu y alloys on thermite reaction has been underexplored.…”

“…Among several types of energetic materials for the thermite reaction, Al-CuO nanothermites have been most intensively investigated, as the combination appears to yield exothermic metallic gas generation [6]. The stoichiometric reaction of Al-CuO composites for ideal combustion is 2Al + 3CuO → Al 2 O 3 + 3Cu, hence the theoretical Al:CuO molar ratio for complete combustion is 2:3.…”

Exothermic characteristics of aluminum based nanomaterials

“…Due to the synergistic effects of the constituent alloying materials, the physiochemical properties of the alloys can be improved by chemical reordering and spatial redistribution of the atoms [8]. In addition, the alloying increases the surface area of the particles that will increase the rate of reaction and improve the reaction mechanism [9][10][11], which in turn shall improve the rate of heat release and the performance of propellants and thermites [12]. Many studies have been conducted in the last a few decades to investigate the thermo-mechanical and chemical activities of aluminum based alloys.…”

The effect of Si–Bi2O3 on the ignition of the Al–CuO thermite

“…In fact, Moore et al [24] showed that even a partial substitution ( 20 wt %) of micron-sized fuel in the Al + MoO 3 thermite is sufficient to reduce the ignition delay times by up to two orders of magnitude and to dramatically increase the combustion velocity. This communication explores further sensitization of the Al + CuO thermite reaction [25] by the fastburning Si + Bi 2 O 3 pyrotechnic composition [26,27]. DTA ignition studies are used to show that the ignition temperature can be reduced significantly even when micron-sized aluminium fuel is retained.…”