Investigating the Interaction Mechanisms of Aluminum Particles in Laser‐Induced Ignition Experiments

ABSTRACT Aluminum (Al) particles are integral to aerospace and defense technologies, yet the mechanisms governing their interactions are not fully elucidated. This research examines the influence of interparticle distance on the ignition and combustion characteristics of Al particle clusters under laser irradiation. By employing ultrasonic dispersion sample preparation and continuous laser irradiation, we isolated the effects of interparticle distance from other variables. As the ratio of interparticle distance to particle diameter escalates from 4 to 9, a concomitant decrease in ignition delay of Al particle clusters is observed, whereas the combustion intensity may experience an increment. Theoretical analyses indicate that interparticle distance significantly modulates the efficacy of laser heat absorption and convective heat transfer during the ignition phase. Consequently, it is inferred that the ignition of Al particle clusters deviates from being governed by the traditional diffusion‐controlled paradigm, which, instead, appears to dictate the combustion process of these clusters. A novel finding from our experiments is the robust correlation between AlO molecular emissions and laser signals, which is attributed to the decomposition of Al 2 O 3 under conditions of extreme energy input. These findings can provide crucial scientific insights for the aluminized solid propellants and explosives.