Experimental investigation on the enhancing effect of reactive materials on explosion fireballs and shock waves of composite charges

This study is aimed at investigating the mechanism by which a reactive material enhances the energy output of a composite charge consisting of an inner explosive, an intermediate non-detonating layer, and an outer explosive, which are widely used in tunable ammunition. Explosion experiments are conducted in two initiation modes. Using reactive Al/rubber significantly increases the fireball growth, shock wave velocity, and shock wave overpressure of the composite charge compared to using inert LiF/rubber. For simultaneous initiation, the increase is more obvious owing to the continuous exothermic reaction of the reactive layer. A composite charge with 40% (vol.) Al shows the highest difference in peak overpressure under the two initiation modes: 41.4%. A charge with 60% (vol.) Al ensures even lower shock wave and fireball velocities and peak overpressure than those of the 40% (vol.) Al charge, indicating that the excessive reactive Al content in the non-detonating layer inhibits the blast of the composite charge.