Ignition and combustion characteristics of single gas-atomized Al–Mg alloy particles in oxidizing gas flow

Abstract

Ignition and combustion characteristics of single gas-atomized Al–Mg alloy particles (Al:Mg = 1:1, 20–210 μm) have been studied in the context of improving the ignition and combustion performance of metal additives in composite solid propellants. In this study, a series of experimental conditions with different oxygen contents and temperatures was designed to examine their effects on the ignition and combustion times of single-alloy particles. The particle sizes, ignition delay times, combustion times, and total times of single-alloy particles were measured synchronously using a two-camera system. Experimental results indicate that the time parameters of single-alloy particles are linearly increased with particle diameters in each experimental condition. Blocked by the oxide film, the alloy particles have a relatively long ignition delay time when they are ignited in high-oxygen-content environments. However, the combustion time of alloy particles decreases as the environmental oxygen content increases. High ambient temperature can remarkably shorten the ignition delay time and total time, but its influence on the combustion time is limited. Microexplosion is also monitored during the ignition and combustion processes. Because of this phenomenon, the combustion times and total times of alloy particles are much shorter than those of same-sized aluminum particles.