Phase Formation and Densification Peculiarities of Hf–C–N Solid Solution Ceramics during Reactive Spark Plasma Sintering.

Herein, phase formation and sintering of hafnium carbonitride ceramics from a 4HfC–3HfN powder mixture using reactive spark plasma sintering are studied. X‐ray diffraction (XRD) data show that the mutual heterodiffusion of carbon C and nitrogen N increases with sintering temperature within the studied temperature range 1500–2100 °C. 4HfC–3HfN powder sintering at 1900 °C for 5 min under 60 MPa pressure yields 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%. [ABSTRACT FROM AUTHOR]