Interfacial properties of SiC_f/SiC minicomposites with a scheelite coating

Unidirectional SiC_f/SiC minicomposite with a scheelite (CaWO₄) interphase coating was fabricated through the precursor infiltration and pyrolysis method. Fractography of the SiC_f/SiC minicomposites indicated that weak fiber/matrix bonding can be provided by the CaWO₄ interphase. Furthermore, interfacial debonding stress of SiC_f/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 SiC_f/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.