Effects of Y₂O₃ and TiO₂ as sintering additive on sintering properties of β-Sialon ceramic

β-Sialon ceramic was prepared by high temperature nitriding reaction of raw material including Al metal powder, Si powder and α-Al₂O₃ fine powder. Adding different mass fractions of Y₂O₃ and TiO₂ as sintering additive, the effect of Y³⁺ and Ti⁴⁺ on the composition, lattice parameters, sintering properties and microstructure of crystalline phases was studied and compared. The crystalline phases and microstructure were determined by XRD and SEM, respectively. The lattice parameters of the crystalline phases were estimated by X'Pert Plus software. The phase composition was evaluated by semi-quantification method. The results show that the addition of Y₂O₃ and TiO₂ makes the formation temperature of β-Sialon lower obviously. Adding of Y₂O₃ and TiO₂ has a beneficial effect on the solid solubility of Al₂O₃ dissolving into Si₃N₄, the content and the lattice parameters of β-Sialon phase increase and the sintering properties are improved. Comprehensive analysis shows that Y₂O₃ and TiO₂ promote the sintering properties of β-Sialon ceramic, the formation of pressureless sintered β-Sialon ceramic is possible using low cost TiO₂ powder instead of the conventional rare earth as sintering additives.