Boron suboxides measured during ignition and combustion of boron in shocked Ar/F/O2 and Ar/N2/O2 mixtures

This paper presents results from an experimental study of crystalline boron particle ignition in a shock tube in pure oxygen and in oxygen/fluorine atmospheres, created by the dissociation of SF6 in Ar and O2, at pressures of about 8.5 atm and at temperatures of about 2600 K. Data are also presented from boron particle combustion experiments in atmospheres containing about 70 percent Ar (by mole fraction) with the balance made up of F and O2 in mole fraction ratios from 0 to 2.0. Additional experiments show the effect of N2 on boron combustion when added to Ar/O2 environments. Small particles, 5-10 microns, are used to ensure that main particle combustion occurs during the relatively short test times (about 1-2 ms) of the shock tube. The results of boron particle combustion tests in these atmospheres are used as a basis of comparison for computer models. (AIAA)