Effects of different fillers on thermal reaction and impact ignition of aluminum/epoxy energetic materials

Abstract

In order to regulate the thermal/impact sensitivity of aluminum/epoxy (Al/Ep)-based reactive materials, a four-component aluminum/epoxy/potassium permanganate/titanium dihydride (Al/Ep/KMnO4/TiH2) reactive materials was proposed. Thermogravimetry-Differential Scanning Calorimetry (TG-DSC) and impact-anvil experiments were performed to study the effect of the mass ratio on the thermal/impact sensitivity of Al/Ep/KMnO4/TiH2 reactive materials combined with Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and x-ray Diffraction (XRD) characterization. The thermal/impact reaction mechanism of the specimens was revealed, and a chemical equation considering the reaction sequence under thermal conditions was established. The results indicate that, in terms of thermal sensitivity, the materials added with KMnO4 exhibit sharp exothermic peaks in the temperature range of 25–800 °C, indicating that KMnO4 can accelerate the reaction rate of the material. In terms of impact sensitivity, there was no ignition reaction in specimens without KMnO4 at a speed of 17.7 m/s, while ignition reaction occurred in specimens with KMnO4. The characteristic drop hammer height of six types was determined to be 45, 37, 41, 62, 42, and 43 cm, respectively. The characteristic drop height H50 of Al/Ep/KMnO4 reactive materials with KMnO4 mass content of 25% was the smallest. Under thermal conditions, Al reacts with manganese dioxide (MnO2) and titanium dioxide (TiO2) to form alloys; however, no alloy formation was observed during the impact process. The addition of KMnO4 lowers the temperature reaction threshold of the Al/Ep-based reactive materials, making it more likely for reactions to be triggered when subjected to external thermal or impact loads. Meanwhile, the incorporation of TiH2 enhances the energy release efficiency.