Surface denitration structure on dynamic combustion performance and muzzle flame of mixed nitrate gun propellant

The gun propellant is an inaccessible energy and fuel for projectile to achieve destructive capability in a weapon system. Nitrocellulose/nitroglycerine/triethylene glycol dinitrate(NC/NG/TEGDN) based gun propellant with higher energy level than single-based gun propellant can meet the demands of modern warfare. Currently, deterring strategy is commonly used to improve the combustion progressivity of NC/NG/TEGDN based gun propellant, together with aggravating the harmful emission phenomena such as muzzle smoke and flame. Therefore, it is essential to design and fabricate NC/NG/TEGDN based gun propellant with both good combustion progressivity and low characteristic signal. In this work, a gradiently denitrated NC/NG/TEGDN based gun propellant was successfully prepared by denitration strategy, whose structure was confirmed by FT-IR, Raman and SEM. Here, closed bomb vessel test and interior ballistic test were conducted. The results showed that the gradiently denitrated NC/NG/TEGDN based gun propellant exhibited better combustion progressivity and interior ballistic performance than raw gun propellant, and these properties can be controlled by modulating the degree of denitration. Meanwhile, the change laws of the muzzle smoke and flame of the gradiently denitrated NC/NG/TEGDN based gun propellant were investigated by the smoke box method and high-speed photography. Furthermore, a lower characteristic signal for the gradiently denitrated NC/NG/TEGDN based gun propellant was found compared to the deterred gun propellant by theoretical calculations. This work provides a new idea for preparing and applying a gun propellant with excellent comprehensive performance, including high energy, good combustion progressivity and low characteristic signal.