Bismuth fluoride-coated boron powders as enhanced fuels

Document Type

Article

Publication Date

11-1-2020

Abstract

By double displacement reaction in aqueous media, bismuth fluoride, BiF3, was coated onto micron-sized boron particles to target two compositions with 5 and 10 wt.% of BiF3, referred to as 95B·5BiF3 and 90B·10BiF3, respectively. The actual mass fractions obtained were estimated to be 3 and 7 wt.%, respectively. The deposited BiF3 particles had narrow size distributions centered around 60 nm. For each of the two prepared powders, the coated boron particles of different sizes contained different mass fractions of BiF3, which scaled with the particle's specific surface area. Both coated samples exhibited a low-temperature oxidation starting at 450 °C, similar to B·BiF3 composite powders prepared by arrested reactive milling. The low-temperature oxidation was sufficiently rapid to sustain ignition of 90B·10BiF3 powder placed on an electrically heated wire. Single particle combustion experiments in air showed a detectable increase in the burn rate for 90B·10BiF3 powder compared to the starting boron; however, no similar increase was noted for 95B·5BiF3 sample. In constant volume explosion tests in air, combustion of 90B·10BiF3 powder generated significantly greater peak pressures and rates of pressure rise than observed for both commercial boron and fine aluminum powders. The improvements were less pronounced, but clearly detectable for 95B·5BiF3 sample.

Identifier

85088806921 (Scopus)

Publication Title

Combustion and Flame

External Full Text Location

https://doi.org/10.1016/j.combustflame.2020.07.023

e-ISSN

15562921

ISSN

00102180

First Page

1

Last Page

10

Volume

221

Grant

N00014-19-1-2048

Fund Ref

Office of Naval Research

This document is currently not available here.

Share

COinS