Effect of the carbon fiber volume fraction on the mechanical properties of SiC matrix composites prepared by spark plasma sintering

In this study, the effect of carbon fiber volume fraction on the microstructure, mechanical, and physical properties of the C_f/SiC composites was investigated. For this purpose, carbon fiber reinforced SiC matrix composites with fiber volume fractions from 0 to 20% and initial SiC powder were produced by the SPS method. The microstructure of sintered samples demonstrates that SiC grains kept its equiaxed shape and carbon fibers degraded through the sintering process. The flexural strength and hardness of the composites decreased continuously by increasing the carbon fiber. However, the maximum fracture toughness of 4.5 MPa.m^1/2 was achieved in the composite with 10 vol % carbon fiber due to the toughening mechanism like crack deflection and bridging.