Fabrication of Transparent AlON Ceramics by Solid-state Reaction Sintering

Transparent AlON ceramic which exhibit excellent optical and mechanical properties is a potential alternative to sapphire for the application of IR windows and armor. In this work, transparent AlON ceramics were successfully prepared by solid-state reaction sintering. The effects of sintering aids and holding time on densification of AlON ceramics were investigated. The phase composition and microstructure of the ceramics were characterized by XRD and SEM, respectively. In-line transmittance of the ceramics was measured by spectrophotometer. The results show that co-doping of MgO and Y2O3 as sintering aid is more effective to enhance densification of AlON ceramics than the doping of MgO or Y2O3. With doping level of 0.08wt%Y2O3, the transmission of ceramics increases with the increase of MgO content. Co-doped with 0.08 wt% Y2O3 and 1 wt% MgO, the ceramics (1mm thick) sintered at 1950 degrees C for 12h in N-2 atmosphere have an in-line transmission of 60% (at 600nm).