Mechanical Properties and Ignition Performance of Rare Earth Reactive Materials under Impact Loading

Aluminum (Al), a commonly used reactive metals, is widely applied in reactive material systems. However, its relatively low reactivity restricts the energy release of systems. To improve the reactivity of aluminum, we introduced aluminum-cerium Al-Ce alloy containing the highly reactive rare earth element cerium into the system. The present study investigated the mechanical properties and ignition performance of four reactive material systems involving Al2Ce/PTFE, Al/PTFE, Al2Ce/ammonium perchlorate (AP), and Al/AP were investigated under shock overload. A split Hopkinson pressure bar (SHPB) system was used to reveal the dynamic stress-strain behavior, ignition delay, and combustion duration of the prepared samples. Thermal analysis was conducted to assess the influence of the reactive metal content on the thermal decomposition of AP. The results showed there are three distinct shock-induced ignition modes: non-ignition, combustion, and combustion (deflagration). Both Al2Ce/PTFE and Al/PTFE exhibited substandard ignition performance. The Al2Ce/AP system demonstrates higher ultimate strength and critical failure strain, achieving deflagration upon impact with significantly shorter ignition delay and combustion duration compared to Al/AP. The incorporation of the cerium accelerates AP decomposition and substantially increased the enthalpy of the Al2Ce/AP system, resulting in more concentrated energy release. Ce effectively enhances the reactivity of aluminum, and its high reactivity accelerates the reaction kinetics of the reactive system. Furthermore, it significantly intensifies energy release under impact loading. In conclusion, the rare earth aluminum alloy materials exhibit a high reactivity, which demonstrates significant potential for the development of aluminum-based impact reaction materials.