A microstructural approach to the chemical reactions during the spark plasma sintering of novel TiC–BN ceramics

In this work, the monolithic TiC and h-BN doped ceramics were spark plasma sintered at 1900 °C for 10 min under 40 MPa pressure. The sinterability and physical-mechanical qualifications of as-produced specimens were studied to assess the impacts of the h-BN additive on TiC-based composites. Adding h-BN did not have any evident effect on the relative density so that both series of specimens achieved the same values around 95%. The X-ray diffraction (XRD) and microstructural evaluations proved the in-situ generation of TiB, TiB₂, TiC and C phases. Although the monolithic TiC samples reached an average hardness of 3128 HV_{100 g}, this value decreased by ~7% when h-BN was added to TiC. Finally, the monolithic sample showed a higher flexural strength (504 MPa) compared with the doped sample (429 MPa).