Synthesis and properties of conductive B4C ceramic composites with TiB2 grain network

High electrical resistance and low fracture toughness of B4C ceramics are 2 of the primary challenges for further machining of B4C ceramics. This report illustrates that these 2 challenges can be overcome simultaneously using core‐shell B4C‐TiB2&TiC powder composites, which were prepared by molten‐salt method using B4C (10 ± 0.6 μm) and Ti powders as raw materials without co‐ball milling. Finally, the near completely dense (98%) B4C‐TiB2 interlayer ceramic composites were successfully fabricated by subsequent pulsed electric current sintering (PECS). The uniform conductive coating on the surface of B4C particles improved the mass transport by electro‐migration in PECS and thus enhanced the sinterability of the composites at a comparatively low temperature of 1700°C. The mechanical, electrical and thermal properties of the ceramic composites were investigated. The interconnected conductive TiB2 phase at the grain boundary of B4C significantly improved the properties of B4C‐TiB2 ceramic composites: in the case of B4C‐29.8 vol% TiB2 composite, the fracture toughness of 4.38 MPa·m1/2, the electrical conductivity of 4.06 × 105 S/m, and a high thermal conductivity of 33 W/mK were achieved.