Fundamental Investigation on the Micro-Explosion of Al-10Li Alloy Particle

The aluminum-lithium alloy particle (Al-Li), due to its micro-explosion during the heating and combustion processes, is deemed to be a promising substitute for conventional aluminum in enhancing the energy release of solid propellant. In this study, a series of flat flame ignition/combustion experiments and ReaxFF molecule dynamics (RMD) simulations were performed to investigate the micro-explosion behaviour of a single Al-10Li alloy particle. The relationship between micro-explosion delay time and particle diameter in different ambient temperatures was obtained from combustion experiments. It is found that smaller particle diameter and higher ambient temperature can accelerate the occurrence of micro-explosions. RMD results reveal the micro-explosion mechanism from atomic scale as the generation and growth of Li cluster are prerequisite for micro-explosion. Exothermic chemical reactions are the main energy source of increasing the particle temperature. The shrinkage stress in the outer shell of the alloy particle and the expansion stress in the internal Li cluster are competitive to the micro-explosion. Additionally, increasing the ambient temperature accelerates the heat transfer and reaction heat release between gases and the particle, thereby shortening the micro-explosion delay time. This study establishes fundamental understanding of the mechanisms governing the micro-explosion of Al-10Li alloy particles, offering potential insights for guiding practical applications of Al-Li alloy particles.