Interfacial properties of SiCf/SiC minicomposites with a scheelite coating

Abstract

Unidirectional SiCf/SiC minicomposite with a scheelite (CaWO4) interphase coating was fabricated through the precursor infiltration and pyrolysis method. Fractography of the SiCf/SiC minicomposites indicated that weak fiber/matrix bonding can be provided by the CaWO4 interphase. Furthermore, interfacial debonding stress of SiCf/CaWO4/SiC minicomposite was evaluated through the fiber push-out test, and estimated to be 80.7 ± 4.6 MPa. In-situ tensile SEM observation of SiCf/CaWO4/SiC minicomposite after oxidation at 1000–1100 °C was carried out, and thermal compatibility between CaWO4 interphase coating and SiC fiber or matrix after heat treatment at 1300 °C was investigated.