Effect of ammonium nitrate and combustible binder on the ignition characteristics of high-energetic materials containing aluminum borides

This paper presents results of an experimental study of the processes of thermal decomposition and ignition of high-energy materials (HEMs) containing an oxidizing agent, a combustible agent, and dispersed additives of aluminum, aluminum borides $(\mathrm{Al}\mathrm{B}_2$ and $\mathrm{Al}\mathrm{B}_{12})$, and amorphous boron. A Netzsch STA 449 F3 Jupiter thermal analyzer and an experimental testbench, which includes a continuous-wave $\mathrm{CO}_2$ laser, are used to investigate the response and ignition characteristics of two basic HEM compositions based on AP/SKDM/Me and PCA/AN/MPVT/Me at different heating rates. It has been established that ammonium nitrate at low heat flux densities ($q<130$ W/cm$^2$) decomposes and melts, forming a liquid layer on the reaction surface and increasing the delay time of the emergence of a HEM flame containing $\mathrm{Al}$, $\mathrm{Al}\mathrm{B}_2$, and $\mathrm{Al}\mathrm{B}_{12}$. With an increase in the heat flux density, the effect of the liquid layer on the reaction surface of the sample decreases due to the rising surface temperature, the outflow rate of gaseous decomposition products, and the layer evaporation.