Structure and phase formation of combustion products during the synthesis of γ-AlON in self-propagating high-temperature synthesis

Abstract

Synthesis of aluminum oxynitride (γ-AlON) in conditions of self-propagating high-temperature synthesis (SHS) gas-statting under high pressures (10–100 MPa) of gaseous nitrogen, including the mode of so-called coupled combustion reactions (chemical furnaces) is investigated. It is shown that chemical and phase compositions of combustion products, as well as their structure and morphology of powder particles, depend on the reagent ratio in Al–Al₂O₃ initial mixture, as well as on nitrogen pressure, combustion temperature of highly exothermic components of chemical furnaces, and grade of initial reagents. The structure of γ-AlON powder particles are determind and its relation with operation conditions of SHS. Optimal SHS parameters for Al₅O₆N (γ-AlON) formation are established.