Preparation of silicon carbide/carbon fiber composites through high-temperature spark plasma sintering

This study discusses the potentials of spark plasma sintering (SPS) integrated with high temperature process that can enable sintering of SiC/Cf composites without any sintering aids. The random distribution of carbon fibers was obtained through mixing composite components in ethanol by using a shaker mill for 10 min. The corresponding sintering process was carried out at 1900 and 2200 °C with 50 MPa pressure applied at maximum temperature. The results showed that 89 ± 0.9 and 97 ± 0.8% of the theoretical density can be obtained for sintering temperatures of 1900 and 2200 °C, respectively. The densification curves were plotted to monitor sintering behavior with punch displacement changes. The appropriate bonding between SiC particles and carbon fibers was detected using FE-SEM for sample which was sintered at 2200 °C. The clear maximum in hardness (2992 ± 33 Vickers), bending strength (427 ± 26 MPa) and fracture toughness (4.2 ± 0.3 MPa m1/2) were identified for sample sintered at 2200 °C. XRD investigations supposed that SiC and carbon were the only crystalline phases in both sintered samples.