Enhancing the Reactivity of Aluminum Powder under Different Heating Rates by Nanoaluminum Powder and Fluororubber

To enhance the energy release of aluminum powder, micro-nanocomposite aluminum powder coated with varying contents of fluororubber (C@Al) was designed and prepared. The micron domain will be formed with the release of energy from the combustion of nanoaluminum powder and gas production from the decomposition of fluororubber. This study demonstrates three key effects at varying heating rates. First, the reaction delay period is shortened, and the reaction is activated. In CO₂ laser ignition tests, micro-nanocomposite aluminum powder coated by 15% fluororubber (C@Al-15%F) has the shortest ignition delay time. Meanwhile, the micro-nanocomposite aluminum powder coated with 10% fluororubber (C@Al-10%F) shows an earlier reaction moment and a lower initial activation energy in thermogravimetric differential scanning calorimetry (TG-DSC) test. Second, the Al–F reaction enhances the released energy. In hot-wire ignition tests, the combustion heat increases with the increase of the fluororubber content. C@Al-10%F shows greater radiation intensity and faster shock wave propagation speed compared to both physically mixed aluminum powder coated by 10% fluororubber (C + Al-10%F) and micrometer aluminum powder coated by 10% fluororubber (C + μAl-10%F) in the rapid heating tests. When added into cyclotrimethylene trinitramine (RDX)/Al/binder explosives, the detonation heat of C@Al-10%F increases by 207 kJ/kg relative to C + μAl-10%F. Third, gas production from fluororubber decomposition can prevent agglomeration. With the increase of the fluororubber content, the peak pressure and burning rates rise significantly. Through the structural design, the synergistic effect of nanoaluminum and fluororubber gives the C@Al-10%F comprehensive performance enhancement, including improving ignition, increasing combustion heat, and promoting product dispersion. These results demonstrate their promising application potential in explosive and related fields.