Microstructure and Mechanical Properties of β-SiAlON Ceramics Fabricated Using Self-Propagating High-Temperature Synthesized β-SiAlON Powder

-SiAlON, based on its high fracture toughness, good strength and low abrasion resistance, has been adopted in several industrial fields such as bearings, turbine blades and non-ferrous metal refractories. In general, -SiAlON is fabricated by reactive sintering using expensive Si 3 N 4 and AlN as starting materials. On the other hand, in this study, a cheaper -SiAlON starting powder synthesized by SHS was employed to improve price competitiveness compared to that of the reactive sintering process. -SiAlON ceramics with various content of the sintering additive Y 2 O 3 up to 7 wt% were fabricated by conventional pressureless sintering at 1800C for 2 to 8 h under N 2 pressure of 0.1 MPa. The specimen with 3 wt% Y 2 O 3 exhibited the best mechanical properties: hardness of 14 GPa, biaxial strength of 830 MPa, fracture toughness of 5 MPam 1/2 and wear rate of about 3 10 -6 mm 3 /Nm.