Improved wettability of barium–aluminium–silicate glass on carbon/carbon composites via coating modification

Abstract

In this paper, three kinds of modification coating were prepared to improve wettability of barium–aluminium–silicate glass on carbon/carbon (C/C) composites. The SiC coating was prepared by pack cementation; Cr₃C₂ and ternary Cr–Si–C coatings were prepared by evaporation reaction process. Contact angles of glass on modified C/C composites were measured at different temperatures by sessile drop technique. Microstructures and morphologies of the wetting interface were determined by scanning electron microscopy, X‐ray diffraction and energy dispersive spectroscopy. Wetting experimental results revealed that barium–aluminium–silicate glass failed to wet the surface of pure C/C composites, but wettability of molten glass on C/C composites clearly improved by surface coating modification. Cr₃C₂ and Cr–Si–C coatings have a better wettability with glass than SiC coating. Cr–Si–C coating shows the best wettability with barium–aluminium–silicate glass, and the contact angle between them can be reduced to only 10° at 1673 K. The effects of test temperatures of sessile drop, coating surface condition and coating dissolution on wettability between glass and coated C/C composites were discussed.