Performance of Ammonia Borane Compared to Aluminum in Thermobaric Explosives

ABSTRACT This paper examines experimentally and theoretically the possibility of using ammonia borane (AB, H 3 BNH 3 ) as an additional fuel in thermobaric explosives. The TBX compositions that were compared consisted of 60% RDX passivated with wax (RDXwax), 20% ammonium perchlorate (AP), and 20% aluminum (Al) powder or H 3 BNH 3 (AB). For each explosive composition, the overpressure histories in a 150 L explosion chamber filled with nitrogen or air at an initial pressure of 0.1 MPa were measured after detonation of 53 g charges. In addition, pressed charges of the explosive compositions with a mass of 500 g were detonated in a 40 m 3 volume bunker. The detonation velocity was measured, and the overpressure waveforms were recorded within 40 ms of detonation. Under explosion chamber conditions, H 3 BNH 3 appears to be a more reactive additional fuel than Al. From a comparison of the blast wave parameters in the bunker, replacing Al with AB was shown, most importantly, to improve the total impulse. The AB‐containing formulation shows, on average, 22% higher values for the TNT equivalents than those determined under identical conditions for the reference composition containing Al instead of AB. The disadvantages of AB as a component of thermobaric explosives include its low density (0.78 g/cm 3 ) and negative influence on the sensitivity of the TBX composition to mechanical and thermal stimuli.