Processing and characterization of fine-grained monolithic SiC ceramic synthesized by spark plasma sintering

Monolithic silicon carbide (SiC) ceramic with good mechanical properties was synthesized by spark plasma sintering (SPS) technique, using granulated SiC powders. The microstructures and the mechanical properties of the ceramics sintered at different temperature were investigated. The results reveal that the SiC ceramic sintered at 1860 °C has relative density of 98.5%, micro-Vickers hardness of 28.5 GPa, bending strength of 395 MPa, and fracture toughness of 4.5 MPa m1/2. By comparison, due to the present SiC ceramic exhibits fine-grained microstructures and the granulated SiC powders was used during the sintering process, the mechanical properties of the SiC ceramic synthesized by SPS are much better than that prepared by common sintering methods.