Characteristics of SiC _f /SiC hybrid composites fabricated by hot pressing and spark plasma sintering

SiC fibre reinforced SiC–matrix ceramic composites were fabricated by electrophoretic deposition (EPD) combined with ultrasonication. Fine β-SiC powder and Tyranno-SA fabrics were used as the matrix and fibre for reinforcement, respectively. Different amounts of fine Al2O3–Y2O3 were added for liquid phase assisted sintering. For EPD, highly dispersed slurry was prepared by adjusting the zeta potentials of the constituent particles to ⩾+40 mV for homogeneous deposition. The composite properties were compared after using two different consolidation methods: hot pressing for 2 h at 20 MPa and spark plasma sintering (SPS) for 3 min at 45 MPa at 1750°C to minimise the damage to the SiC fibre. The maximum flexural strength and density for the 45 vol.-% fibre content composites were 482 MPa and 98% after hot pressing, respectively, whereas those for SPS were 561 MPa and 99·5%, indicating the effectiveness of SPS.