Ignition and combustion properties of NGO coated AlH3

AlH₃ is a highly promising additive for energetic materials and has gained considerable attention as a substitute fuel for aluminum in solid propellants. In order to improve its compatibility with energetic materials and oxidants, carbon coating materials are often used. Nitrated graphene oxide (NGO) was prepared and used as a surface modifier of α-AlH₃ in our study. Various analytical techniques were utilized to examine its structure and morphology, including Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), particle size distribution (PSD) and X-ray diffraction (XRD). The oxidization, ignition characteristics, flame propagation behavior and heat of combustion of AlH₃ and AlH₃/NGO powder were investigated using differential thermal analysis (DTA), a laser igniter, a high-speed camera and an oxygen bomb calorimetry. Results show that NGO coating agent catalyzes the thermal decomposition and hydrogenation process of AlH₃, and accelerates the oxidation process of AlH₃. The addition of 4 % NGO decreases the oxidation activation energy of AlH₃ by about 8.94 %. The laser ignition energy of AlH₃/NGO is much lower than that of AlH₃, and the ignition energy decreases linearly as NGO is added from 1 % to 10 %. The flame development process supports the good thermal conductivity assistance effect of an appropriate amount of NGO in the combustion process of AlH₃ in air, which is consistent with the result of oxygen bomb test, indicating that the addition of NGO leads to an improvement in the combustion efficiency of AlH₃.This may provide valuable insights for the development of new high-energy solid propellants.