Phase formation and densification peculiarities of Hf–C–N solid solution ceramics during reactive SPS

This paper studies phase formation and sintering of hafnium carbonitride ceramics from a 4 HfC–3 HfN powder mixture using reactive spark plasma sintering. XRD data show the mutual hetero‐diffusion of carbon C and nitrogen N increases with sintering temperature within the studied temperature range 1500‐2100 °C. 4 HfC–3 HfN powder sintering at 1900 °C for 5 min under 60 MPa pressure yields in HfCxN1‐x solid solution ceramics. The ceramic sample prepared under optimal conditions (2100 °C, 5 min, 60 MPa) is characterized by an average grain size of 10 μm, microhardness of 19.6–22.5 GPa and relative density above ∽97%.