Laser Ignition of Different Aluminum Nanopowders for Solid Rocket Propulsion

Abstract

Aluminum nanopowders (nAl) coated with oleic acid (nAl@OA), perfluorotetradecanoic acid (nAl@PA) and nickel acetylacetonate (nAl@NA) were prepared. The ignition and combustion characteristics of different aluminum nanopowders were studied using the laser ignition system. And the combustion characteristics of hydroxyl-terminated polybutadiene (HTPB)-based composite solid propellants containing different coated aluminum nanopowders were also investigated. The results show that there is a critical power of laser heat flux density in the ignition process of the coated aluminum nanopowders. The ignition delay time of nAl@NA is shorter than that of nAl@PA and nAl@OA, because of the combustion catalysis of nickel acetylacetonate. The burning rate of the propellant sample containing nAl@NA is the highest among all the formulations at different pressure ranges, and the maximum burning rate is up to 26.13 mm·s−1 at 15 MPa. The burning rates of propellant samples containing nAl@OA and nAl@PA are almost the same at different pressures and higher than that of the propellant samples containing untreated aluminum nanopowders only at the pressure range of 10–15 MPa. The flame intensity of different propellants at different pressure is not the same. Moreover, the surface coated aluminum nanopowder has a little effect on the combustion flame temperature of solid propellant. The burning surface temperature of propellant increases with an increase in pressure.