Environmentally Sustainable Gasless Delay Compositions for Fuzes, Mn/MnO_2 and W/MnO_2 Pyrotechnic Delay Studies

摘要

Pyrotechnic delay compositions are used by the U.S. Military in a variety of munitions, especially infuzes for hand grenades. Thousands of these items are expended on training ranges every year, creatinga significant risk of range contamination. The replacement of hazardous delay compositions with benignalternatives is therefore of great importance to the Department of Defense. We have studied thethermodynamics and kinetics of the Mn/MnO_2 and W/MnO_2 thermitic systems, which show great promiseas candidate replacement compositions for use in M201A1 and M213/M228 hand grenade fuzes.Equations 1‐6 represent plausible pyrotechnic reaction pathways for Mn/MnO_2 and W/MnO_2mixtures. In the Mn/MnO_2 system, X‐ray diffraction experiments revealed that MnO and Mn_3O_4 areproduced by fuel‐lean compositions whereas MnO and excess Mn are present in the residues producedby fuel‐rich compositions. Interestingly, Mn2O3 was not detected. The W/MnO_2 system produces mostlyMnWO_4, but also some Mn3WO6 and Mn3O4 in amounts that depend on the fuel/oxidizer ratio. Here, MnOwas not found. However, the manganese tungstate compounds may be thought of as combinations ofMnO and WO_3 (equations 7, 8).