Optimization of the optical properties of alpha-SiAlON through a decrease in starting powder size

In the present work, the effects of initial powder size on the sintering behavior and optical properties of Dy-alpha-SiAlON ceramics produced by the SPS technique are investigated. The powders were prepared using high energy and conventional milling processes to make comparisons. The powders, prepared by conventional processes, were used as a standard. After sintering, the infrared transmittance behavior of the SiAlON ceramics was investigated in a wavenumber range of between 7000 and 1000 cm(-1) using an FTIR. The microstructure and phase characterization of the samples were carried out using an SEM and the XRD method, respectively. It was observed that the secondary crystalline phases, the sizes of grains and the distribution of the glassy phase around the grains were the main factors that affected the transmittance of the samples. As a result, it was shown that the starting particle size of raw materials had a significant effect on the microstructure and optical properties of the samples. (C) 2015 Elsevier Ltd. All rights reserved.