Gas desorption properties of TiC/C compositionally graded coatings on doped graphite

To mitigate carbon contamination from doped graphite (1% B, 2.5% Si, 7.5% Ti) by irradiation of plasma, TiC/C compositionally graded coatings (CGCs) were prepared by chemical vapor deposition. Scanning electron microscopy (SEM) results indicated that the TiC/C CGCs were characterized by avoidances of cracks and loosely bonded particles. Gas desorption results suggested that out gas amount increased with the increase of temperatures. However, it was much lower than that of pure TiC coatings after irradiation for 300 s.