Effects of Microwave Sintering Temperature and Holding Time on Mechanical Properties and Microstructure of Si<sub>3</sub>N<sub>4</sub>/n-SiC ceramics

oleh: Li Qiao, Zhenhua Wang, Taiyi Lu, Juntang Yuan

Format: Article
Diterbitkan: MDPI AG 2019-11-01

Deskripsi

The n-SiC (nanometer SiC) is added to be the additive in order to improve the mechanical performance of Si<sub>3</sub>N<sub>4</sub> ceramics. A microwave sintered the ceramics at different temperature and holding times. The results shows that the Si<sub>3</sub>N<sub>4</sub>/n-SiC ceramics (85 wt% Si<sub>3</sub>N<sub>4</sub> + 5 wt% n-SiC + 5 wt% Al<sub>2</sub>O<sub>3</sub> + 5 wt% Y<sub>2</sub>O<sub>3</sub>) have the best mechanical properties at 1600 &#176;C, which is beneficial to the densification and &#946;-Si<sub>3</sub>N<sub>4</sub> phase formation for 10 min: the density, hardness, and fracture toughness were 97.1%, 14.44 GPa, and 7.77 MPa&#183;m<sup>1/2</sup>, which increased by 2.8%, 7.0%, and 13.1%, respectively, when compared with the ceramics (90 wt% Si<sub>3</sub>N<sub>4</sub> + 5 wt% Al<sub>2</sub>O<sub>3</sub> + 5 wt% Y<sub>2</sub>O<sub>3</sub>).