Abstract
Si-M(Ti, Zr)-C-O fiber/SiC composites with a thin carbon layer between the fibers and matrix provide good strength and fracture properties. These properties deteriorate in a high-temperature oxidizing atmosphere due to the oxidation of the carbon layer. Such deterioration could be prevented by stopping oxygen penetrating from the outside through pores and cracks in the matrix.
We fabricated Si-M-C-O fiber/SiC composites containing traces of glass which was expected to seal cracks as it softened under high temperatures. We evaluated the oxidation characteristics and creep properties of this glass-containing composite in comparison with a composite having no glass added.
The addition of SiO2-Al2O3-BaO effectively sealed cracks at high temperatures thereby inhibiting oxidation of the carbon layer and silicate formation near the fiber surface. We also confirmed that the addition of SiO2-Al2O3-BaO reduced creep strain rate and significantly increased creep lifetime.
