Callaghan Innovation Research Papers

Back to Research Papers

TitleInfluence of nitrogen overpressure on the nitridation, densification and formation of β-SiAlONs produced by silicothermal reduction
Publication TypeJournal Article
Year of Publication2013
AuthorsRouquié, Y., Jones M.I., Brown I.W.M., and White G.V.
JournalJournal of the European Ceramic Society
Pagination859 - 867
Date Published2013
ISSN09552219 (ISSN)
Keywordsatmospheric pressure, Crystalline phase, nitridation, Nitrided, nitrogen, Nitrogen pressure, Over-pressures, Overpressure, Reaction rates, Reaction sequences, Sialon phase, Sialons
Abstractβ-SiAlON materials (with z=1) with 2mol% DyAG have been synthesised by silicothermal reduction under different nitrogen pressures. The possibility of rapidly nitriding silicon and forming the SiAlON phase has been investigated through its reaction sequence of formation under different pressures. β-SiAlONs were fully nitrided (degree of nitridation greater than 93%) and formed after a 1-h hold at 1400°C, or after a straight ramp to 1500°C under 0.7MPa of nitrogen. This was not achievable under static nitrogen at atmospheric pressure where the degree of nitridation was only 43% and β-SiAlON phase represented only about 60% of the crystalline phase assemblage at the same temperature. The formation of β-SiAlON depended on the formation of Si3N4 whose reaction rate was enhanced by nitrogen overpressures. © 2012 Elsevier Ltd.

Back to top