Sintering temperature study of hot-pressed Y-SiAlON ceramics

In order to investigate the effect of sintering temperature on the microstructure and densification process of Y-SiAlON ceramics, by hot pressing at 1750°, 1800°, 1850° and 1900°C for 1 h, respectively, Y-α-SiAlON (m=1.2, n=1.2 according to formula M_m/3Si _12-(m+n)Al_m+nO_nN_16-n) was fabricated from α-Si₃N₄, AlN, Al₂O₃ and Y₂O₃ starting powers. The results showed that α-SiAlON phase is formed in all sintered specimens, and during Y-SiAlON sintering, all the samples begin to quickly shrink at 1550°C, and the shrinkage is finished at 1750°C, which indicate that 1550 - 1750°C is very important for the densification process of Y-α-SiAlON ceramics, and 1750°C is necessary for the Y-SiAlON densification. Higher sintering temperature contributes to α-SiAlON grain development and the SiAlON ceramics densification.