Oxidation behavior of pack-cemented, thermal etched SiC coating with Al–B–C additions

Silicon carbide (SiC) coating with Al–B–C additions (designated ABSC2) was fabricated by pack cementation and subsequent thermal etching (argon and nitrogen atmosphere). In addition, the roles of thermal etching on the microstructures and oxidation behaviors for ABSC2 coating were examined. The ABSC2 coatings subjected to thermal etching show superior oxidation resistance to that without thermal etching. Further, the ABSC2 coating subjected to thermal etching in a nitrogen atmosphere (designated ABSC2N) shows the best oxidation resistance of −0.3% (weight gain) after 12 h at 1500 °C. This may be attributed to the elimination of bulk secondary phases and the extra oxidation of the numerous SiC whiskers.