Pressureless sintering of highly transparent AlON ceramics with CaCO3 doping

Abstract Employing CaCO 3 as sintering additive, highly transparent aluminum oxynitride (AlON) ceramics were pressurelessly fabricated from AlON powder at 1870 °C during150 min. The transmittance of the AlON doped with 0.3–0.4 wt% CaCO 3 is up to 83–85% at ~3700 nm for 2 mm thickness samples, and their transmittances are consistently higher than that of the AlON doped with the ideal amount of Y 2 O 3 at wavelength ranging from 200 nm to 6000 nm. The AlON doped with CaCO 3 exhibits the transmittance of 71% at 4800 nm (typical band for infrared targeting), which is higher by 6% than that of the doped Y 2 O 3 .