Abstract:
The β-Sialon ceramics were fabricated by spark plasma sintering, using 10% Y
2O
3‒Al
2O
3‒ZrO
2 composites (mass fraction) as sintering additives. The effects of sintering temperature on the phase composition, microstructure, mechanical and tribological properties of the ceramics were investigated. The results show that the relative density, Vickers hardness, and fracture toughness of the β-Sialon ceramics firstly increase and then decrease from
1300 ℃ to
1800 ℃, reaching the maximum at
1700 ℃. The ZrN impurity phases are observed in the samples sintered at
1500 ℃,
1600 ℃, and
1800 ℃ with the relatively low relative density; only the β-Sialon phases are observed in the samples sintered at
1700 ℃ with the uniform grain distribution and few small pores. The best overall performance is obtained at
1700 ℃ with the relative density of 98%, Vickers hardness of 15.15 GPa, fracture toughness of 5.55 MPa·m
1/2, and wear rate of 3.75×10
–6 mm
3·(Nm)
‒1.