High Hardness and Ductile Mosaic <scp> <scp>SiC</scp> </scp> / <scp> <scp>SiO</scp> </scp> ₂ Composite by Spark Plasma Sintering

Abstract

SiC powder was coated with SiO 2 layer by chemical vapor deposition, and the SiC (core)/ SiO 2 (shell) composite powder was consolidated to a SiC / SiO 2 composite with a mosaic microstructure by spark plasma sintering ( SPS ) at 1923 K for 1.8 ks. The SiC (core)/ SiO 2 (shell) powder with a 80–100 nm thick SiO 2 layer resulted in a SiC / SiO 2 composite with a relative density of 97% and hardness and fracture toughness of 17.1 GPa and 8.4 MPa m 1/2 , respectively.