THERMOCHEMICAL PROPERTIES AND LASER-IGNITION PERFORMANCE OF Al/CuMoO4, Al/CuO/MoO3, Al/CuO AND Al/MoO3 NANOTHERMITES

Nanothermites represent materials of high energy density and reaction rate which also exhibit sensitivity to friction initiation and electrostatic discharge (ESD). New nanothermite materials based on the perovskite CuMoO4 have been produced by resonant acoustic mixing and compared to the corresponding nanothermites containing MoO3 and CuO oxidants. Three fuels have been used in the study, containing oxide (O-Al) passivation or palmitic acid (L-Al) and Viton (V-Al) coatings. Whilst the materials show intermediate friction and ESD sensitivity between molybdenum and copper nanothermites, a friction sensitivity of 96 N and ESD minimum ignition of > 0.156 J is achieved using V-Al fuels, which is markedly improved relative to MoO3-based nanothermites. All three CuMoO4-based nanothermite fuels reacted rapidly under thermochemical conditions in argon at ≤ 500°C. Reactions are complete over a few degrees of the heating cycle, rather than a few hundred degrees for the MoO3 and CuO nanothermites. Contrary to the reaction under thermochemical conditions (ignition by constant heating), the low power laser initiated (ignition by hot-spot) perovskite thermite had shown less reactivity when compared to the other nanothermites. The most reactive nanothermite to laser ignition was found to be the Al/CuO/MoO3 nanothermite. Therefore, both the binary oxide and perovskite should be considered as a distinct nanothermite system, with properties that are different than individual MoO3 and CuO systems.