Preparation of Boron Suboxide Nanoparticles and Their Processing

Abstract

Crystalline boron suboxide B₆O particles with size in the range of 1.5 µm – 2 µm and crystallite size in the range of 32 nm – 40 nm were prepared by calcination at 1400 °C for one or two hours of precursors obtained by mixing X-ray amorphous boron with water solution of B₂O₃ followed by evaporation and drying. Decrease of molar ratio B/B₂O₃ from 16 to 14 in the precursor mixture reduced nonstoichiometry of prepared B₆O although simultaneously it increased admixture of B₂O₃. Particulate composites of B₆O with TiN or Ni nanoparticles were prepared by mechanical mixing. The spark plasma sintering process intensified the densification of prepared boron suboxide nanoparticles at 1900 °C and allowed manufacturing of fully dense bodies (98 %) during five minutes. Additives of TiN or Ni nanoparticles reduced sintering temperature to 1700 °C and their promoted formation of Ti or Ni borides.

DOI: http://dx.doi.org/10.5755/j01.ms.18.1.1345