SiC-MoSi₂-(Ti_0.8Mo_0.2)Si₂ multi-composition coating for carbon/carbon composites

To protect carbon/carbon (C/C) composites from oxidation, a new type of oxidation protective coating has been produced by a pack cementation technique in an argon atmosphere. XRD and SEM analysis showed that the phases of the composite coating were composed of SiC, MoSi₂, and (Ti_0.8Mo_0.2)Si₂. Oxidation test discovered that the weight loss of the SiC coated C/C was up to 11.26% after 5 h oxidation in air at 1773 K and the weight loss of the SiC-MoSi₂-(Ti_0.8Mo_0.2)Si₂ coated C/C composites characterized by excellent thermal shock resistance was only 2.18% in the same condition for 49 h. The oxidation of the coated C/C composites was primarily due to the reaction of the C/C matrix and oxygen diffusing through the penetrable cracks in the coating.