Laser ignition and combustion properties of composite propellant containing nanometal powders

Abstract

The effect of nanometal powders (nano-grain-size aluminum powders and nanograin size nickel powders) on the ignition delay time of ammonium perchlorate composite propellants has been examined in detail within a carbon dioxide laser ignition system. A comparison of different experimental techniques for combustion-related properties evaluation, including burning rates, deflagration heat, and ignition temperatures of the ammonium perchlorate propellants containing nanometal powders is presented. A thermogravimetric analyzer is employed to investigate the thermal behavior of nano-grain-size and general-grain-size aluminum powders heated in air. The content of active aluminum in the combustion residue was measured by means of the titration. The results show that, with the cooperating effect of nanonickel powders, the addition of nanoaluminum powders in propellants can greatly increase the burning rate, shorten the ignition delay time, and improve the combustion efficiency of aluminum in the combustion of propellant. The individual application of nanometal powders (nanoaluminum or -nickel powders) displayed an intermediate effect, whereas the general-grain-size nickel powders had the least effect. The effect of nano-grain-size Al is determined to be on the solid-phase ignition of the propellant. The effect of nano-grain-size Ni is determined to be on the gas-phase ignition of propellant initially and the solid-phase ignition subsequently.