Effects of aluminum on combustion characteristic of HTPE propellants

The surface morphology of four kinds of aluminum powders with different particle sizes was observed by scanning electron microscope (SEM), and the effects of four different particle sizes of aluminum powder on the combustion performance of HTPE propellant were studied by means of underwater acoustic emission method, differential sanning calorimetry and high-speed photography. The results show that the smaller the particle diameters of aluminum powder, the higher the burning rate pressure index of HTPE propellant, and its pressure index will increase from 0.26 to 0.48 in the pressure range of 5-11MPa. And as the particle size of aluminum powder decreases, the combustion activation energy shows a decreasing trend. When the pressure increases from 2MPa to 4MPa, as the particle size of the aluminum powder decreases, its specific surface area increases, the reaction activity becomes higher, and the aluminum powder combustion performance becomes more intense and sufficient, the maximum combustion flame temperature of the propellant increased from 2375°C∼2403°C to 2425 °C ∼2482 °C, respectively, and the overall flame temperature fluctuation range was relatively small.