Utilization of Industrial Waste Alloy as An Alternative to Micron-Al in Energetic Applications

Abstract

Aluminum-enhanced solid propellant is one of the most commonly used propellants people have ever developed. It is cost-effective, simple to store and handle, and energetic for thrust production due to the extremely high burning temperature of aluminum (Al) particles. However, a large-scale manufacturing of micro-sized aluminum powders with a narrow size distribution and high purification is still challenging, while the spontaneously formed oxidation layer on the surface of Al particles significantly reduce their reactive content. Here, we report on the feasibility of using AlSi10Mg micron particle, an industrial waste alloy from additive manufacturing with a median diameter of 13 μm, as a promising alternative for aluminum microparticles in propulsion applications. Compared to Al micron particles with a similar diameter, AlSi10Mg showed the comparable reaction temperature and activation energy. However, AlSi10Mg produced a much higher energy release, indicating its more complete oxidization as an alloy than Al particles with the inert Al2O3 shell. DSC-TGA results of the mixtures of those two micro-sized powders with CuO nanoparticles exhibited a similar reaction kinetics which indicates the involvement of gaseous oxygen. In combustion tests, the AlSi10Mg/CuO mixture showed a much shorter ignition delay compared to pure Al/CuO mixture, revealing its enhanced reactivity. The combustion rate of AlSi10Mg/CuO was found to be much higher than Al/CuO, and the thrust generation of AlSi10Mg/CuO was also more than 30% higher than Al/CuO in an atmospheric environment. Combustion of AlSi10Mg/CuO and Al/CuO in a low-pressure environment was also investigated. All these results indicated that micro-sized alloy particles recycled from the advanced manufacturing can replace Al micron particles for propulsion and energy production.