Journal of the American Ceramic Society, Vol.87, No.9, 1726-1733, 2004
Tensile and stress-rupture behavior of SiC/SiC minicomposite containing chemically vapor deposited zirconia interphase
The tensile and stress-rupture behavior of SiC/SiC minicomposite containing a chemically vapor deposited (CVD) ZrO2 interphase was evaluated. Fractographic analyses showed that in situ fiber strength and minicomposite failure loads were strongly dependent on the phase contents and microstructure of the ZrO2 interphase. When the ZrO2 interphase structure possessed a weakly bonded interface within the dense ZrO2 interphase coating layer, the interphase sufficiently protected the fiber surface from processing degradation and promoted matrix crack deflection around the fibers. With this weakly bonded interphase, the stress-rupture properties of SiC/SiC minicomposite at 950degrees and 1200degreesC appeared to be controlled by fiber rupture properties, and compared favorably to those previously measured for state-of-the-art BN fiber coatings.