Effects of Microwave Sintering Temperature and Holding Time on Mechanical Properties and Microstructure of Si3N4-SiC ceramics

摘要

The n-SiC (nanometer SiC) is added to be the additive in order to improve the mechanical performance of Si N ceramics. A microwave sintered the ceramics at different temperature and holding times. The results shows that the Si N -SiC ceramics (85 wt% Si N + 5 wt% n-SiC + 5 wt% Al O + 5 wt% Y O ) have the best mechanical properties at 1600 °C, which is beneficial to the densification and β-Si N 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% Si N + 5 wt% Al O + 5 wt% Y O ).