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

Aluminum (Al), one of commonly used reactive metals, is widely appliedin reactive material systems. However, its relatively low reactivity restricts the energy release of systems. To improve the reactivity of Al, we introduced aluminum-cerium alloy (Al-Ce alloy) which include the rare-earth cerium with high reactivity into the system. This study investigated the mechanical properties and ignition performance of four reactive material systems under shock overload—Al₂Ce/PTFE, Al/PTFE, Al₂Ce/ammonium perchlorate (AP), and Al/AP. A split Hopkinson pressure bar (SHPB) system was used to study the dynamic stress-strain behavior, ignition delay, and combustion duration of the prepared samples. Thermal analysis was conducted to assess the influence of reactive metal content on the thermal decomposition of AP. Results showed there are three distinct shock-induced ignition modes: non-ignition, combustion, and combustion (deflagration). Both Al₂Ce/PTFE and Al/PTFE exhibited poor 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 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. Besides, it significantly intensifies energy release under impact loading. In conclusion, rare earth aluminum alloy materials, due to their high reactivity advantage, are of great significance for the development of new aluminum-based impact reaction materials.