Changed oxidation behavior of ZrB2–SiC ceramics with the addition of ZrC.

Oxidation behavior of ZrB 2 –SiC ceramics containing 0, 10 and 20 vol% ZrC was studied at 1600 °C in stagnant air. The structures of oxide scales depended on ZrC content. The thickness of the SiO 2 -rich glass layer on the outermost surface decreased steeply with the addition of ZrC. One “ZrC-corroded layer”, containing ZrC x O y , SiC and ZrB 2 , was observed in ZrB 2 –SiC–ZrC. The oxidation kinetics was converted from parabolic to linear for the ceramics with 20 vol% ZrC. [ABSTRACT FROM AUTHOR]