Intermetallic Compounds as Fuels for Composite Rocket Propellants

Aluminized composite propellants have long suffered from efficiency and thermal challenges related to production of condensed phase slag droplets during operation. In an effort to mitigate the production of large droplets, a mechanically activated intermetallic forming nickel-aluminum compound was substituted for a portion of a propellant’s aluminum fuel. The resulting agglomerate size and burning rate of this propellant was compared to a standard aluminized AP/HTPB propellant. Addition of mechanically activated fuel particles increased the burning rate exponent of the propellant, while simultaneously decreasing condensed phase agglomerate size from 235 µm (for the control propellant) to 90 µ m( for the propellant containing 75 wt.% Ni-Al fuel). As such, intermetallic forming fuels may provide a route for increasing efficiency in solid rocket motors by simultaneously reducing the need for burning rate catalysts and minimizing two-phase nozzle flow losses.