Abstract
A SiC coating was prepared on carbon/carbon (C/C) composites by a two-step technique of pack cementation and CVD processes to prevent these composites from oxidation. SEM, EDS and XRD were applied to analyze the surface and cross-section morphologies, element distribution and phase composition of the coating, respectively. The results show that a transitional layer with gradient distribution of Si and C content is formed between the SiC coating obtained by pack cementation process and C/C substrate, and the compact coating prepared by CVD process effectively fills the pores of the coating by pack cementation. The coating made by the two-step technique exhibits excellent oxidation protective ability. The weight loss percentage of the coated C/C composites is only 2.01% after oxidation in air at 1500°C for 60 h. The weight loss of C/C composites is primarily due to the reaction of C/C and oxygen diffusing through the microcracks in the coating during the thermal cycle between 1500°C and room temperature.
| Original language | English |
|---|---|
| Pages (from-to) | 737-741 |
| Number of pages | 5 |
| Journal | Wuji Cailiao Xuebao/Journal of Inorganic Materials |
| Volume | 22 |
| Issue number | 4 |
| State | Published - Jul 2007 |
Keywords
- Carbon/carbon composites
- Chemical vapor deposition
- Coating