Investigations of TaB2 on oxidation-inhibition property and mechanism of Si-based coatings in aerobic environment with broad temperature region for carbon materials

To investigate the formation mechanism of the dendrites glass-ceramics and the effect of TaB2 modifier on the oxidation-inhibition ability of Si-based coatings in aerobic environment with broad temperature region for carbon materials, the Si-based coatings modified with different TaB2 content were fabricated by the liquid phase sintering method. The fabricated coatings and its corresponding composite powders were investigated in dynamic TG aerobic environments up to 1500 degrees C. The initial oxidation temperatures of Si-based coatings modified with TaB2 powders are almost completely suppressed to 800 degrees C. With the increase of TaB2 phase content, the relative oxygen permeability of the Si-based coatings is significantly reduced, which can be interpreted as the generation of liquid boride, silicide and Ta-Si-B-O compound glass ceramics those can improve the stability of the coating. The formation mechanism of the dendrites glass-ceramics was illustrated.