Impact Response Test and Ignition Characteristics of HMX/Al Energetic Composites Based on the Force–Electric Coupling Method under a Drop Hammer

HMX/Al is an energetic composite formed during the manufacturing and processing of mixed explosives, and its safety has been explored under the action of force and electrostatic field. In order to investigate the impact response and ignition characteristics of HMX/Al energetic composites based on the force-electric coupling method, a self-designed force-electric coupling impact test device was adopted to carry out the impact sensitivity test of composite explosives under the influence of different factors. The model of HMX/Al energetic composites was established under the effect of force-electric coupling, and the critical ignition voltage and the response ignition mechanism were obtained under the conditions of the force-electric coupling test. The results show that under the condition of fixed drop height, the critical ignition voltage of the impact response of HMX/Al first decreases and then gradually increases with the increase of Al powder content; when fixing the content of Al powder, the greater the strength of the applied electric field, the more intense the impact ignition response of HMX/Al energetic composites; the greater the strength of the restraining shell, the more significant the degree of the ignition response of the HMX/Al energetic composites. The F₂₆₀₂ binder used for coating HMX has an inhibitory effect on the ignition response of explosives under the force-electric coupling test; the critical ignition voltage of composite powder is smaller than that of the pressed tablets with the same formula. Under the influence of external impact loads, hot spots form inside the explosives. Simultaneously, the Joule heating effect generated by an external power source continuously heats, causing heat accumulation and ultimately leading to an explosion. Therefore, HMX/Al energetic composites are more dangerous under force-electricity coupling, and the results of the study have a certain reference significance for the safety assessment of energetic materials under compound stimulations.