Different effects of Al on the decomposition of HATO under non-isothermal and adiabatic conditions

Explosives containing Al powder have higher detonation energy and heat. However, while pursuing detonation performances, the thermal safety of explosives with Al is equally important. To research the effect of Al on the thermal stability of dihydroxylammonium 5,5'-bistetrazole-1,1'-diolate (HATO), the thermal decomposition of HATO and mixtures of HATO with Al were studied by differential scanning calorimetry and accelerating rate calorimeter. Under non-isothermal conditions, Al has a catalytic effect on the decomposition of HATO, manifested by the lower apparent activation energies (E_a) of the three mixtures compared to that of HATO. The thermal stability for the mixtures of HATO with Al was the best when the Al content was 30%. Besides, the onset temperatures of the mixtures were jointly affected by the heating rate and Al content. Furthermore, at the adiabatic conditions, the addition of Al increased the thermal conductivity of the mixtures, resulting in faster heat dissipation of the mixtures compared to HATO. This led to the mixtures having higher values of E_a than HATO and when the Al content was 25%, the mixture had the highest E_a. Additionally, the addition of Al prolonged the reaction time of HATO.