A Si-SiC oxidation-resistant coating for carbon/carbon composites by hot-pressing reaction technique

A Si-SiC coating was prepared by hot-pressing reactive sintering (HPRS) technique for protecting carbon/carbon (C/C) composites against oxidation. The Si-SiC coating has a dense and crack-free structure with a thickness of 70-90 μm. The Si-SiC coating by HPRS has a higher SiC content and lower Si content than the coating by pressure-less reactive sintering (PRS). It also exhibits better oxidation-protective ability than that prepared by PRS. With hot-pressing, the flexural strength of the Si-SiC coated C/C composites decreases from 121 MPa to 99 MPa, and the interface bonding strength increases from 6 MPa to 10 MPa.