Combustion behavior of composite solid propellant reinforced with Al-based alloy fuel

• Spherical Al-based alloys are applied to replace Al in solid composite propellants. • Microexplosion promotes the combustion of Al. • Al-Mg and Al-Zn propellants show higher flame temperature and less product agglomeration. To reduce the combustion agglomeration of Al particles, Al-based alloys including Al-Mg, Al-Zn, Al-Si, are applied to replace Al in the solid propellant specimen. Combustion behaviors of these propellants are recorded using a high-speed camera and an infrared thermometer. Combustion products were collected and the particle morphology and phase makeup were analyzed using electron microscopy and X-ray diffraction. Results reveal that the propellants containing Al-Mg and Al-Zn have much stronger flame and higher temperature than that of Al or Al-Si, since the microexplosion caused by the low-boiling point Mg and Zn promotes the combustion of Al. Propellant product analysis shows that Al-Mg and Al-Zn powders produce fewer agglomerates compared with Al and Al-Si. This work provides a deeper understanding towards further applications of Al-based alloy in solid propellants.