High-strength and -toughness electroconductive SiC-based composites

SiC-based electroconductive composites were obtained through addition of different amounts of MoSi2 particles (10, 30 vol%). The composite materials were fully densified by hot pressing at 1900°C and the microstructures were investigated by SEM-EDS analysis. Microstructural features and mechanical properties were compared to those of the reference SiC and MoSi2 materials. The MoSi2 particles, besides increasing the electrical conductivity of the silicon carbide matrix, also acted as reinforcement for the material. For the composition containing 30 vol% of MoSi2, the room-temperature strength was 825 MPa, the fracture toughness 4.8 MPa×m0.5 and the electrical resistivity 1.3×10-3 Ohm×cm