Study On The Pressureless Sintering Of AION Transparent Ceramic

AlON transparent creramic is a new kind of materials with structural functional integration, has excellent optical and mechanical properties. It is widely used in wireless electronic technology, special equipment manufacturing and other areas, has broad developing prospect. At present, the foreign study on transparent ceramics has made some achievements, and domestic study had a late start, and the production level also has a largh gap, so studying on preparation and related issues of A10N transparent ceramic is of great significance.This paper used AlON powder as the raw material which was prepared by carbothermal reduction method, then AlON powder was added in0.5%of Y2O3as sintering additives. And after the processes of wet milling, dry forming and pressureless sintering in N2, AlON transparent ceramics could be prepared. And studied on effect rules of slab forming pressure, cooling rate, sintering temperature and holding time on ceramic phase composition, microstructure and optical performance of AlON.The results show that:The samples after sintering which were formed in50Mpa have minimum number of cracks and high transmittance value, the density is also very close to the theoretical value, and the optical performance is superior to the samples in50Mpa and100Mpa; Controlling cooling rate can be effectively reduced the sample damage of thermal stress during cooling process, cooling slowly can greatly improve transmittance of AlON transparent ceramics; the high sintering temperature and long holding time will cause excessive nitrogen behavior on AlON, and the low sintering temperature and short holding time will cause the samples’phase transformation incompletely and densification not high, these factors will affect the transmittance of the samples, the best sintering technic for high transmittance of AlON transparent ceramics:at the sintering temperature of1820℃to1880℃, and the holding time of 90min to150min.