Aluminum oxynitride by SHS under high pressure of nitrogen gas

Abstract

Aluminum oxynitride (γ-AlON) powders were prepared from low-caloric Al–Al₂O₃ mixtures by SHS under high pressure of nitrogen gas in the presence of heat-generating agent, Mg(ClO₄)₂, as a booster. The preparation procedure was characterized and optimized with respect to Al/Al₂O₃ ratio, amount of heatgenerating additive, and nitrogen gas pressure. The morphology of synthesized γ-AlON powders was found to depend on Al powder brand. Compared to γ-AlON powders obtained in chemical furnace, we managed to prepare less sintered arenaceous cakes that could be easily disintegrated into target γ-AlON powder. SHSproduced powders may find their application in production of optical ceramics.