Library Subscription: Guest
Begell Digital Portal Begell Digital Library eBooks Journals References & Proceedings Research Collections
International Journal of Energetic Materials and Chemical Propulsion
ESCI SJR: 0.28 SNIP: 0.421 CiteScore™: 0.9

ISSN Print: 2150-766X
ISSN Online: 2150-7678

International Journal of Energetic Materials and Chemical Propulsion

DOI: 10.1615/IntJEnergeticMaterialsChemProp.v2.i1-6.110
pages 211-217

A SIMPLE MODEL OF THE OXIDATION KINETICS OF BORON IN A MEDIUM CONTAINING WATER VAPOR

R. Sontgen
DLR-Institute for Chemical Propulsion and Engineering, D-7101 Hardthausen a.K., Germany
A. Friedrich
DLR-Institute for Chemical Propulsion and Engineering, D-7101 Hardthausen a.K., Germany

ABSTRACT

The oxidation behavior of elementary boron in humid atmospheres is studied in the temperature range between 973 and 1373 К by thermoanalytical methods. In the absence of water vapor, boron forms protective surface layers of B2O3 following a parabolic rate law. In pure oxygen at temperatures above the melting point of B2O3, after an induction period of about 8 min a spontaneous ignition is observed. In air as in a pure oxygen atmosphere, the oxidator is oxygen.
Water vapor changes the reaction mechanism. The oxidator oxygen is substituted by gaseous H2O at temperatures above 810 K, consuming the whole boron by formation of boron oxide and hydrogen. The reaction rate depends only slightly upon the water content of the surrounding atmosphere. Hydrogen is detected by gaschromatography in the exhaust gas. In addition, the oxide layer is diminished due to an enhanced evaporation of metaboric acid formed at the outer sphere of the coated boron grain.


Articles with similar content:

A Mathematical Model of Surface-Reaction Diffusion
International Journal of Fluid Mechanics Research, Vol.27, 2000, issue 2-4
A. O. Ivanov, Yu. A. Elfimov
Role of CO2 in the Soot Formation and Reduction Mechanisms in CH4 Flat Flame Doped with Toluene under O2/CO2 Environments
International Heat Transfer Conference 15, Vol.7, 2014, issue
Shunsuke Sugai, Ken Okazaki, Hirotatsu Watanabe
FORMATION OF HARD AND WEAR-RESISTANT NIOBIUM CARBIDE COATINGS ON HARD-ALLOY TOOLS BY A VACUUM–ARC METHOD
High Temperature Material Processes: An International Quarterly of High-Technology Plasma Processes, Vol.23, 2019, issue 2
Andrej K. Kuleshov, V. M. Anishchik, I. A. Sakovich, D. P. Rusalski, Alexander A. Malashevich, Vladimir V. Uglov, V. A. Firago
REACTIONS OF POWDERED ALUMINUM WITH EXPLOSIVES THAT SELECTIVELY FORM CARBON DIOXIDE OR WATER AS OXIDIZERS
International Journal of Energetic Materials and Chemical Propulsion, Vol.15, 2016, issue 4
Larry G. Hill, V. Eric Sanders, Carl Johnson, Bryce C. Tappan, Steve J. Pemberton, Virginia W. Manner, Mark A. Lieber
WHY AND HOW TYPE OF PASSIVATION LAYER AFFECTS THE PROPERTIES OF ALUMINUM NANOPOWDERS FOR ENERGETIC APPLICATIONS
International Journal of Energetic Materials and Chemical Propulsion, Vol.6, 2007, issue 2
Alexander Gromov, Ulrich Forter-Barth, Ulrich Teipel