Pressureless sintering of transparent AlON ceramic with assimilable γ‐Al2O3 as sintering promoting additives.

Transparent aluminum oxynitride (AlON) ceramic was successfully fabricated without doping sintering additive by the pressureless sintering method. Γ‐Al2O3 nano‐powder that can be assimilated by the AlON matrix was used for promoting the densification of AlON during the sintering. The sintering behavior of AlON and the effects of γ‐Al2O3 nano‐powder on the phase, hardness, and transmittance of AlON have been investigated in detail. The mechanisms of γ‐Al2O3 nano‐powder on the AlON green body modifying and the sintering promoting are revealed. The transmittance of the AlON ceramic is dramatically enhanced by doping γ‐Al2O3 nano‐powder and the 2 mm thick sample doped with 2.5 wt% γ‐Al2O3 nano‐powder shows an inline transmittance above 81% at 1500 nm. [ABSTRACT FROM AUTHOR]