Influence of SiC Whisker on Formation and Oxidation Resistance of Coating for C/C Composite

To protect carbon/carbon (C/C) composite against oxidation, a SiC/Si/MoSi2 anti-oxidation coating was preparated on C/C composite by embedding with the powder mixture of Si, C and MoSi2 at 1600 degrees C in argon atmosphere. In order to investigate the effection of SiC whisker on formation and oxidation resistance of coating, SiC whisker was introduced to coatings by pyrolysis of hydrogen silicone oil (H-PSO) at 1600 degrees C before embedding treatment. Oxidation experiment was carried out in the static air at 1400 degrees C for 2h, and thermal cycling between 1400 degrees C and room temperature for 5 times. Morphology and phase structure of the coating were analyzed by XRD and SEM with EDS. The anti-oxidative mechanism of coating was investigated by comparing the diversity of morphology and phase structure before and after oxidation. The research indicates that the introduction of SiC whiskers improves the performance of the coating effectively. It can effectively decrease the cracking of the coating in the oxidation process, and avoid the excessive penetration of silicon to protect the matrix from being excessively corrosion.