Advertisement

Journal of Materials Science

, Volume 41, Issue 15, pp 4921–4927 | Cite as

Role of boron carbide in carbothermic formation of hexagonal boron nitride

  • H. E. Çamurlu
  • N. Sevinç
  • Y. Topkaya
Article

Abstract

Formation of hexagonal boron nitride by carbothermic reduction of boric oxide under nitrogen atmosphere at 1500 °C was investigated. Experiments were performed for durations in the range of 15 min to 3 h. Reaction products were subjected to powder X-ray diffraction analysis, chemical analysis and were examined by scanning electron microscope. Formation of hexagonal boron nitride was found to be complete in 3 h with most forming in the initial 2 h. Boron carbide was found to exist in the reaction products of the experiments in which hexagonal boron nitride formation was not complete. The aim of this study was to investigate the role of boron carbide in the carbothermic production of hexagonal boron nitride. For this purpose, conversion reaction of boron carbide into hexagonal boron nitride was studied. Boron carbide used in these experiments was produced in the same conditions that hexagonal boron nitride was formed, but under argon atmosphere. It was found that formation of hexagonal boron nitride from boron carbide—boric oxide mixtures was slower than activated carbon—boric oxide mixtures. It was concluded that boron carbide is not a necessary intermediate product in the carbothermic production of hexagonal boron nitride.

Keywords

Boron Activate Carbon B2O3 Boron Nitride Boron Carbide 

Notes

Acknowledgements

This project was supported by the State Planning Organization of the Turkish Government through the Academic Human Resources Program and by Middle East Technical University grants.

References

  1. 1.
    Haubner R, Wilhelm M, Weissenbacher R, Lux B (2002) Boron nitrides – properties, synthesis and applications. Springer-Verlag, Berlin Heidelberg, p 14Google Scholar
  2. 2.
    The Economy of Boron (2002) Roskill information services, London, p 250Google Scholar
  3. 3.
    Bartnitskaya TS, Ya Kosolapova T, Kurdyumov AV, Oleinik GS, Bilyankevich AN (1986) J Less-Common Met 117:253CrossRefGoogle Scholar
  4. 4.
    Yoon SJ, Jha A (1996) J Mater Sci 31:2265CrossRefGoogle Scholar
  5. 5.
    Pikalov SN (1988) Powder Metall Met C+ 27:404Google Scholar
  6. 6.
    Aydoğdu A, Sevinç N (2003) J Eur Ceram Soc 23:3153CrossRefGoogle Scholar
  7. 7.
    Cullity BD, Stock SR (2001) Elements of X-ray diffraction. Prentice Hall, New Jersey, p 169Google Scholar
  8. 8.
    Sinha A, Mahata T, Sharma BP (2002) J Nucl Mater 301:165CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2006

Authors and Affiliations

  1. 1.Department of Metallurgical and Materials EngineeringMiddle East Technical UniversityAnkaraTurkey

Personalised recommendations