Flame propagation in Al/MoO3 thermites is measured as a function of bulk density and initial sample temperature. The composites are composed of nano-scale reactant particles mixed and pressure molded to between 49 and 73% of the theoretical maximum density. A relationship between cylindrical die pressure and final pellet density is derived. Experiments are also performed by initially pre-heating samples to a uniform temperature ranging from 20 to 200°C. Ignition sensitivity was determined by measuring the ignition delay time and temperature using a 50-W CO2 laser and thermocouples, respectively. Combustion wave speeds were measured using high-speed imaging diagnostics. Results allow comparison of combustion behaviors associated with nano- vs. micron-scale particle composites. The nano-scale particle composites are extremely sensitive to ignition, especially when initially preheated. Combustion wave speeds for the compressed nano-composites were found to double when compared to the micron-scale composites.
|Number of pages||6|
|Journal||Materials Research Society Symposium - Proceedings|
|State||Published - 2003|
|Event||Synthesis, Characterization and Properties of Energetic/Reactive Nanomaterials - Boston, MA., United States|
Duration: Dec 1 2003 → Dec 4 2003