The influence of particle size of AP and AL on the performance of underwater explosives

This paper describes formulations for underwater explosives and there properties. Beside traditional components like Al, RDX and AP the energetic binder system based on glycidyl azide polymer (GAP) was used for all compositions. The influence of variations in contents of Al (25/ 30 %), RDX (27/ 52 %) and AP (0/ 25/ 30 %) was studied whereas the binder content has been retained unchanged at 18 %. Compositions were also developed to investigate the influence of particle size of AP and Al. The different explosives were characterized in terms of sensitivity, stability and performance. As expected AP increased obviously the impact- and friction sensitivity. Similar results showed the Fast-Cook-Off Test. Increasing AP content reduced the event temperature but the sharpness of reaction did not increase and did not run into detonation. In detonation velocity testing the AP containing explosives showed reduced velocities. The underwater performance was measured by charge weights of 1 and 9 kg and compared to the TNT-based German underwater explosive SSMTR 8870. All formulations outperformed the traditional German underwater explosive SSMTR 8870 in terms of shock wave energies and bubble energies. Especially the explosives with AP showed good performances.