Experimental Study of Emptying A-Ⅸ-Ⅱ Explosive Using Submerged Cavitation Water Jet

To explore the process and safety of emptying ammunition charge by submerged cavitation water jet, relative experiment al research was carried out with A-Ⅸ-Ⅱ explosive as the experimental object. The split Hopkinson pressure bar (SHPB) device was applied to obtain stress-strain mechanical properties of A-Ⅸ-Ⅱ. The emptying experimental system was set up to investigate the impact crushing effect and mechanism of cavitation water jet on A-IX-II. Scanning electron microscope (SEM) was used to characterize the morphology of broken particles and gain the mesoscopic breakup mode of A-Ⅸ-Ⅱ. The internal temperature of A-Ⅸ-Ⅱ during the impact process of cavitation water jet was measured with a self-designed thermocouple temperature measurement device, and the experimental safety was discussed by combining the results of differential scanning calorimetry (DSC) of A-Ⅸ-Ⅱ. The results show that stress-strain curves of A-Ⅸ-Ⅱ include three stages: brittle-elastic stage, nonlinear elastoplastic stage and strain softening stage, and the damage under dynamic loading shows strain rate effect. It is greatly available to use cavitation water jet to empty A-Ⅸ-Ⅱ explosive in fifteen minutes and the maximum particle size of the collected A-Ⅸ-Ⅱ explosive is no more than 3 cm. The damage of A-Ⅸ-Ⅱ is mainly caused by the strong impact of micro-jet and shock wave when the cavitation bubble collapses. The mesoscopic breakup mode is mainly the inter crystalline separation of crystals from binder and aluminum powder, accompanied by a small amount of trans granular phenomenon, and no crystal breakup is found. It is safe to empty A-Ⅸ-Ⅱ explosive by using submerged cavitation water jet as the highest temperature in the experiment is 50 ℃, which is lower than the temperature required for thermal initiation (160 ℃). © 2020, Editorial Board of Chinese Journal of Energetic Materials. All right reserved.