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

摘要

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 △Tm =0.8～2.2 °C,apparent activation energy alter ratio(AAEAR)△Eα/△E0 =12.5%~17.8%,ignition probability due to friction sensitivity Pf=0.32～0.48 and to impact sensitivity Pi=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 400um.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.