Reactive material aluminum/nickel fluoride and its thermal reaction properties

Aluminum/nickel fluoride is a new kind of reactive material with high reactivity, high gas yield and strong stability, whose reaction properties and reaction mechanism are yet to be explored. Nano-aluminum/nickel fluoride (n-Al/NiF₂) composites were prepared by an ultrasonic mixing process, and the thermal analysis and kinetic studies were compared with those of nano-aluminum/nickel oxide (n-Al/NiO). In an Ar environment, n-Al/NiF₂ had a lower reaction temperature (530.0 °C) and gave off more heat (2196.0 J·g⁻¹) compared to n-Al/NiO (629.1 °C). In an air environment, n-Al/NiF₂ also had a lower reaction temperature (500.6 °C), but the heat release (1215.2 J·g⁻¹) was lower than that of n-Al/NiO (1466.5 J·g⁻¹). All heat effects were measured at a heating rate of 10 K·min⁻¹. With increasing temperature, n-Al/NiF₂ undergoes five stages of change in the air: low-temperature dehydration, decomposition of metal fluoride, reaction of n-Al with fluorine, reaction of n-Al with oxygen, and high-temperature sublimation of AlF₃. The XRD analysis shows no pre-ignition reaction occurred during the reaction. The reaction activation energy of n-Al/NiF₂ was compared and analyzed with that of n-Al/NiO and other aluminum/fluorides. The investigation of the thermal response properties of n-Al/NiF₂ will contribute to the understanding of the thermal response mechanism of aluminum/fluorides and provide a basis for the development of new reactive materials.