Experimental Study of PTFE Powder Size Impact to Mg/PTFE Pyrotechnic Composition

To discover the polytetrafluoroethylene (PTFE) powder size impact to Mg/PTFE pyrotechnic composition, hot compatibility of various particle sizes of PTFE powder with spherical superfine Mg powder was studied. Safety performance of Mg/PTFE pyrotechnic composition was also researched by parameters of friction and impact sensitivity. Burning temperature and velocity were recorded and analysed. The result shows that the Mg/PTFE exothermic temperature peak floats =0.8~2.2°C, apparent activation energy alter ratio (AAEAR) =12.5%~17.8%, ignition probability due to friction sensitivity =0.32~0.48 and to impact sensitivity =0. It indicates that PTFE powder size will not inflect the safety of Mg/PTFE composition, which burns more stable with PTFE size great than 400μm. Once mass combustion velocity 2.09~3.87 g•cm-2•s-1 and linearcombustion velocity 5.02~8.13 mm•s-1, the combustion velocity will increase much by following with PTFE particle sizes decrease.