388224 Flame Propagation of Al/PTFE Mechanically Activated Composites

Thursday, November 20, 2014: 1:58 PM
211 (Hilton Atlanta)
Travis R. Sippel and Liyun Feng, Department of Mechanical Engineering, Iowa State University, Ames, IA

The confined propagation velocity of nanoscale aluminum (nAl) and polytetrafluoroethylene (PTFE) metastable intermolecular composites (nAl/PTFE MICs) can be high due to convective heating that can occur at the reaction interface of discrete fuel/oxidizer particles. Unlike MICs, preheating of reactions in mechanically activated micron-sized Al/PTFE composites can occur through both inter-particle convection and intra-particle conduction. Preheating can be further dependent upon equivalence ratio, as for some ratios, reaction products are condensed-phase. The goal of this work is to determine the individual influences of conduction and convection on confined, mechanically activated Al/PTFE flame propagation by varying equivalence ratio, particle size, and intra-particle mixing (e.g. milling treatment). Instrumented tube combustion experiments are conducted in which optical and pressure wave propagation in mechanically activated Al/PTFE composites is observed using photodiodes and piezoelectric pressure transducers, respectively. Using similar packing densities while varying particle size, intra-particle mixing, and equivalence ratio, the effects of conduction and convection can be isolated.

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See more of this Session: Nano-Energetic Materials II
See more of this Group/Topical: Particle Technology Forum