Effects of Microwave Sintering Temperature and Holding Time on Mechanical Properties and Microstructure of SiN/n-SiC ceramics.

The n-SiC (nanometer SiC) is added to be the additive in order to improve the mechanical performance of SiN ceramics. A microwave sintered the ceramics at different temperature and holding times. The results shows that the SiN/n-SiC ceramics (85 wt% SiN + 5 wt% n-SiC + 5 wt% AlO + 5 wt% YO) have the best mechanical properties at 1600 °C, which is beneficial to the densification and β-SiN phase formation for 10 min: the density, hardness, and fracture toughness were 97.1%, 14.44 GPa, and 7.77 MPa·m, which increased by 2.8%, 7.0%, and 13.1%, respectively, when compared with the ceramics (90 wt% SiN + 5 wt% AlO + 5 wt% YO).