Study On Application Of Nano-Aluminum Powder In Solid Propellant

In this paper, the methods of enhancing the available aluminum content of nano-aluminum powders have been analyzed, the properties of nano-aluminum powders which were made by evaporation-condensation(EC) and electrical exploding wires(EEW) have been characterized. The storage stability of nano-aluminum powders in different environment has been studied. The dispersion technique of nano-aluminum powders in propellant has been researched. The propellant of nano-aluminum powder has been made and the properties of combustion, energy and mechanics have also been studied.The results show that it can enhance the available aluminum content of the nano-aluminum powders by choosing right nano-aluminum particle size, using organic coated, a high degree of spherical nano-aluminum powder and reasonable packaging.The available aluminum content of nano-aluminum powders can be more accurately measured by redox titration. The available aluminum content of nano-aluminum powders prepared by EEW have reached 85%, and the combustion heat is close to ordinary aluminum. The obvious oxidation peak of nano-aluminum powders is about 500～650℃.The active aluminum content of nano-aluminum powders were affected by atmosphere, humidity and temperature. As to 80nmAl, the most remarkable influence is humidity, the second is temperature, and the least is atmosphere. The vacuum dry condition is the best method for storage. The storage life of 200nmAl is 468 days at 25℃by decreasing 10% content of active aluminum.TEM can characterize the dispersion condition of nano-aluminum powders in the HTPB system preferably. The effect of ultrasonic dispersion is better than ball milling and high-speed mixing. COF plays an important role in the nano-aluminum powders dispersion process. The ultrasonic dispersion of solution and slurry make the average size of nano-aluminum powders reach to 100nm, the effect of solution ultrasound are slightly better than slurry ultrasound.Nano-aluminum powder and other components of propellant have a good compatibility, and the pore-free compact propellant was made successfully. The joining of highly active aluminum powders increased the propellant energy, the more content, the higher energy and burning rate, the smaller pressure exponent; the smaller diameter, the higher burning rate. The smaller particle can improve the mechanical properties of the propellant and enhance the tensile strength. The smaller particle size, the greater elongation, when the content of nano-aluminum powders is up to 5%, the elongation of propellant is significantly higher than the foundation formula.