Burning Velocities in Catalytically Assisted Self-Propagating High-Temperature Combustion Synthesis Systems

The current work presents an experimental study of catalytically assisted self-propagating high-temperature synthesis (SHS) of the tantalum/carbon material system. The effects of controlled amounts of two gas-phase transport agents (carbon dioxide and vaporized iodine) were examined. The gas-phase transport agents resulted in burning velocities 2 to 4 times faster than burning velocities observed in comparable catalytically assisted and unassisted Ta/C SHS systems. The gas-phase transport agents clearly augment the combustion synthesis process. The burning velocities of the catalytically assisted, non-melting SHS systems were found to be strong functions of particle size, pressure and the amount of gas-transport agent present. The results are compared with previous studies of both catalytically assisted and unassisted Ta/C SHS, and discussed in the context of proposed transport mechanisms. © 2001 by The Combustion Institut