Studies on the Characteristics of UFAL Containing Composite Propellant

摘要

The addition of 15～23wt.% of 5～60μm aluminum powder in the conventional high-energy composite propellants is a common practice. Incorporation of aluminum powder in propellant results in performance enhancement is quite obvious, however, it has only limited influence on propellant burning rate. In this research, it is interested to note that if H-30(～30μm) aluminum powder is gradually replaced by 0.2μm UFAL(ultra fine aluminum) powder in low to high burning-rate propellants, the burning rate increased with the UFAL content, but with a diminished effect. When 18% aluminum is totally replaced by UFAL, the burning rate increased by 1.6 times. However, in the case of a very high burning rate propellant, the burning rate enhancement effect is less pronounced. High-speed videotape clearly shows most UFAL particles are ignited and burned in condensed phase. This phenomenon is attributed to the superior reactivity of UFAL particles, which causing higher subsurface temperature and consequently enhances burning rate. In addition, QPCB data confirms smaller agglomerated residues of UFAL containing propellants. The unique characteristics of UFAL render it not only suitable for propellant application but also good for pyrotechnics, gas generators, and even for airbag inflator.