Effects of process on microstructure and properties of translucent Dy-α-SiAlON sintered at lower temperatures

Abstract

Hot pressing (HP) at higher sintering temperature has been a traditional and prevalent technique for the fabrication of αSiAlON. In order to prepare translucent SiAlON more easily, LiF was used as a non-oxide sintering additive to lower the sintering temperature to ≤ 1650°C. As a result, all of the samples possessed a good hardness and fracture toughness. At the same time, the lower temperature sintered samples showed a higher optical transmittance in the range of 2.5-5.5 μm wavelength (0.5 mm in thickness). The maximum infrared transmission reached 68% at a wavelength of 3.3 μm. The present work shows that the sintering process has a strong effect on microstructure and property of α-SiAlON. To be exact, a lower sintering temperature and longer holding time can produce some fully-developed microstrcture, which is beneficial for the optical transmittance. © 2008 The Ceramic Society of Japan. All rights reserved.