Fundamental investigation on the micro-explosion of aluminum-lithium alloy particle

YT Zhou and Q Mao and NGS Ing and QZ Chu and LJ Liao and BL Shi, COMBUSTION AND FLAME, 274, 113983 (2025).

DOI: 10.1016/j.combustflame.2025.113983

The aluminum-lithium (Al-Li) alloy particle is considered to be a promising alternative for conventional aluminum particles to enhance energy release in solid propellants, owing to its tendency to undergo micro- explosions during combustion processes. In this study, both laser-induced ignition/combustion experiments and reactive molecular dynamics (RMD) simulations were performed to comprehensively capture the complete micro-explosion sequence of Al-Li alloy particles under a high- pressure oxygen condition. In combustion experiments, higher heating rates and Li concentrations effectively increase the probability of micro-explosions and shorten both the ignition delay time and the combustion time of Al-Li alloy particles. Meanwhile, RMD results reveal the micro-explosion mechanism from atomic scale, highlighting that the aggregation, melting, boiling and growth of Li cluster are the prerequisites for micro-explosion. The competition of stresses in the outer shell and inner Li cluster determine the micro-explosion phenomenon. In addition, influences of heating rates and Li concentrations on the micro-explosion were well clarified and their dependence was summarized. A high heating rate provides more energy to atoms within the Al-Li alloy particle through reactions and collisions, thereby shortening the duration of the atomic diffusion stage before micro-explosion. Furthermore, a high Li concentration enhances the expansion stress of the Li cluster to shorten the cluster growth stage. This systematic study establishes a fundamental understanding of the intricate mechanisms governing the micro-explosion of Al-Li alloy particles, offering potential insights for guiding practical applications.

Return to Publications page