Comparative Study on Combustion Behavior of Aluminum-Based Alloy Fuels and Aluminum Powder in Solid Propellants

In order to reduce the ignition temperature and improve the combustion efficiency of aluminum powder, three aluminum-based alloy fuels, Al–Mg, Al–Zn, and Al–Si–Mg, were prepared by the atomization method. The oxidation, ignition, and combustion performance of alloy fuels were investigated, and the results showed that, using pure aluminum powder as a reference, the weight gain of alloy fuels increased from 10% to 84%, the reaction activation energy decreased from 582 kJ·mol⁻¹ to 208 kJ·mol⁻¹, the alloy fuels containing Mg had good ignition response, and aluminum-based alloy fuels showed high calorific value and efficient combustion as a whole. In order to investigate the combustion behavior of alloy fuels in the solid propellant, tests were conducted on the mechanics, safety, process, and combustion properties of propellant according to the national standard, and the test results showed that, compared with the propellant made of aluminum powder with same quality, the propellant made of alloy has better mechanical properties, higher frictional sensitivity, lower electrostatic sensitivity, comparable process performance, and increased combustion calorific value and combustion speed. Engine test results confirmed that Al–Zn and Al–Si–Mg alloy fuels could effectively improve the specific impulse efficiency of the solid propellant and reduced the residual rate of the engine.