Multiple zirconia interphase for SiC/SiCf composites

A multiple zirconium dioxide interphase for SiC/SiCf composites was developed using the sol–gel approach. The morphology, elemental composition, topography, and tensile strength of ZrO2 coated Nicalon™ CG fibers were examined using scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS), atomic force microscopy (AFM), and single filament tensile strength analysis as a function of the number of coats. The interfacial frictional stress values of the SiC/SiCf and SiC/(ZrO2)n/SiCf minicomposites were evaluated using micro indentation tests. shown that the presence of multiple ZrO2 coating on Nicalon™ CG promotes decoupling of the fibers from the matrix and frictional pullout, with the fiber sliding pressure decreases as a number of coats increase. Due to strong bonding at the fiber/coating and the matrix/coating boundaries, on the one hand, and weak bonding between interfacial layers, on the other hand, debonding and sliding occur within the interphase. the fiber/matrix decoupling in SiC/(ZrO2)n/SiCf minicomposites can be regulated by designing the multiple ZrO2 interphase.