Co-dopants effect on translucent SiAlON ceramics production

SiAlON is a ceramic alloy (solid solution of Si3N4-Al2O3) which is discovered in the early 1970s. Since then, SiAlON ceramics have been used for structural applications due to its excellent fracture toughness and strength, outstanding chemical stability, and wear resistance. However, this material has also an enormous potential for functional applications. In this study, the effects of co-dopants on the IR transmittance of alpha-SiAlON ceramics were investigated. Compositions were designed by using two different cation combinations (Dy3+-La3+) and (Y3+-La3+). Starting powder mixtures were sintered by means of spark plasma sintering (SPS) technique. Microstructure and phase characterization of the samples was carried out by scanning electron microscope (SEM) and X-ray diffraction (XRD), respectively. The infrared transmission of alpha-SiAlON ceramics was measured by Fourier transform infrared spectroscopy (FTIR) in the range of 2000-7000 cm(-1). The results were discussed according to the relationship between density, phase composition, microstructure, and optical properties.