Preceramic Paper-Derived SiC_f/SiC_p Composites Obtained by Spark Plasma Sintering: Processing, Microstructure and Mechanical Properties

Ceramic matrix composites (CMCs) based on silicon carbide (SiC) are promising materials for applications as structural components used under high irradiation flux and high temperature conditions. The addition of SiC fibers (SiC_f) may improve both the physical and mechanical properties of CMCs and lead to an increase in their tolerance to failure. This work describes the fabrication and characterization of novel preceramic paper-derived SiC_f/SiC_p composites fabricated by spark plasma sintering (SPS). The sintering temperature and pressure were 2100 °C and 20-60 MPa, respectively. The content of fibers in the composites was approx. 10 wt.%. The matrix densification and fiber distribution were examined by X-ray computed tomography and scanning electron microscopy. Short processing time avoided the destruction of SiC fibers during SPS. The flexural strength of the fabricated SiC_f/SiC_p composites at room temperature varies between 300 and 430 MPa depending on the processing parameters and microstructure of the fabricated composites. A quasi-ductile fracture behavior of the fabricated composites was observed.