High-temperature reactive spark plasma consolidation of TiB2–NbC ceramic composites

The TiB2–NbC ceramic system was consolidated by reactive spark plasma sintering (SPS). Densification, phase relations, microstructure evolution, and their effect on the properties of SPS-consolidated TiB2–NbC bodies were examined. The densification of TiB2 was enhanced by the addition of NbC, with 10 wt% NbC being the most effective. The phases that developed during reaction-driven consolidation of the NbC–TiB2 system at 2000 °C were (Nb,Ti) carbide and (Ti,Nb) diboride solid solutions and 1–2 µm TiB2 grains. The best balance between hardness (24 GPa) and fracture toughness (6.8 MPa m−2) was found in 30 wt% NbC–TiB2 composites consolidated at 2000 °C for 5 min.