Reactivity of Coated Boron Particles in Combustion Environments

Period of Performance: 11/19/1991 - 12/19/1993

$496K

Phase 2 SBIR

Recipient Firm

Aerochem Research Labs, Inc.
P.O. Box 12
Princeton, NJ 08542
Principal Investigator

Abstract

Thin coatings of reactive metal have been shown to enhance the reactivity of boron particles in a combustion environment. Phase I research indicated that Mg-coated, 3 pm diameter amorphous boron particles ignited at earlier times and lower temperatures and burned more quickly than identical, uncoated boron particles in a set of atmospheric pressure hydrogen/oxygen/nitrogen flames. This is the first experimental demonstration that thin reactive metal coatings enhance the reactivity of boron particles in combustion environments. With this demonstration, the concept of coating boron particles for use as practical fuels has been made credible and the need for funher work has been emphasized. The proposed Phase II work will provide quantitative validation of this enhancement in a variety of combustion environments, extending the measurements on the system studied in Phase I, and additionally exploring carbon monoxide/oxygen, nitrogen, hydrocarbon/oxygen/nitrogen and nitrous oxide/oxygen/nitrogen flames. The effects of coating material (Mg, AI), coating thickness, boron particle purity and phase, and particle size on reactivity will be determined. In addition, the pyrolysis and ignition of boron loaded solid fuel pellets will be compared using coated and uncoated boron particles. Physical and chemical mechanisms for the enhancement effect will be developed and tested using the data.