Recent Progresses on Synthesis and Evaluation of AlH3

Aluminum hydride(AlH3)has high hydrogen content capacity(mass content>10%), low molecular weight of com bustion products and relatively high thermal decomposition temperature. AlH3 can significantly improve the energy level of solid propellants by partially replacing aluminum powder, so it is considered as a very important high-energy fuel. However, there is critical dependence of the solid propellant performances on the quality of AlH3 crystals. The choice and optimization of preparation method largely determines the quality and cost of the products. It has been shown that the unstable nature of AlH3 could greatly affect the aging and storage performances. Moreover, the incompatibility between some components and AlH3 decreases the safety of corresponding solid propellants. The problems mentioned above are the key technical issues and need to be solved before large-scale application of AlH3 in solid propellant formulations. The advances in synthetic techniques for AlH3 and its application in solid propellants over the world have been introduced in this review paper. The stabilizing strategies and post evaluation of AlH3 in relevant research institutes are summarized as well, based on which the future research directions are proposed. The literature shows that the safety and quality control during scaling-up of AlH3 can be solved by using ether synthetic method. The applicability of AlH3 in solid propellant can be greatly improved by surface treatment, including coating of AlH3. © 2019, Editorial Board of Chinese Journal of Energetic Materials. All right reserved.