要約

This paper presents the combustion behavior of a solid propellant formulation with 15% ultra-fine aluminum powder called Alex whose grain size is around 50 to 200 nm. To evaluate the propellant burning results, a second comparable solid propellant was produced, containing 15% conventional aluminum YX 76 (Pechiney) with a grain size in the order of 10 to 100 μm. Both aluminum powders are compatible with the propellant formulation. REM examinations show that the shape of Alex is spherical whereas YX 76 has the aspect of flakes. The combustion experiments are performed in a high-pressure closed vessel at loading densities corresponding to pressures up to 280 MPa. These experiments allow to determine the constants of the Abel equation of state (co-volume and force), the dynamic vivacity and the burning rate. Although both propellant grains have the same geometry (flakes), the burning behavior is quite different. For a given pressure, the burning rate of the Alex propellant is always higher than that of the YX 76 propellant. For each propellant, a VIEILLE burning law is given. The burning rate pressure exponent of the Alex propellant is very low, as compared to that of the YX 76 propellant. The Alex propellant can be useful for applications in the high-pressure rocket propulsion as an igniter or as a booster, and also for projectiles as an additional accelerator.