Oxidation of SiC and decomposition of SiO2 at low partial pressure of oxygen in He-O2 system

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 109 KB
• Volume: 234
• Category: Article
• ISSN: 0029-5493
• DOI: 10.1016/j.nucengdes.2004.08.001

✦ Synopsis

The critical temperature of passive oxidation for SiC and the critical temperature of decomposition for SiO 2 are very important for the application of SiC and SiC/SiO 2 coatings. Through thermodynamic analysis, it is found that the influence factor controlling the critical temperature of passive oxidation for SiC in He-O 2 is the partial pressure of oxygen, and the critical temperature increases with the partial pressure of oxygen. The critical temperature of decomposition for SiO 2 in He-O 2 is influenced by the partial pressure of oxygen and the amount of oxygen per mole SiO 2 , and this critical temperature increases with the partial pressure of oxygen, while it decreases with the amount of oxygen. SiC/SiO 2 coating is more suitable than SiC coating for the improvement of the oxidation resistance of graphite at low partial pressure of oxygen in He-O 2 system.