Synergystic properties of dual phase (Hf,Ti,Zr)B2–(Hf,Ti,Zr)C ceramics

Dual phase mid entropy carbide/ boride ceramics were produced by boro/carbothermal reduction followed by spark plasma sintering. Based on the transition metal distribution in the dual phase ceramics, individual mid entropy boride and carbide ceramics were produced. The hardness value for the dual phase ceramic was 43.5 ± 5.1 GPa at a load of 0.49 N while value calculated using a volumetric rule of mixtures was 36.2 GPa based on measured hardness values of the constituents. Thermal conductivity of the optimized dual phase ceramic was ∼15 % higher than the constituent single phases. The dual phase ceramic also had an electrical resistivity that was ∼35 % lower than the value calculated from the individual constituents. For the dual phase ceramic, the phonon contribution was approximately 44 % of the total conductivity, indicating that the mid entropy boride phase had a dominant effect on the electrical resistivity of the dual phase ceramic.

Duke Scholars

Author Stefano Curtarolo Thomas Lord Department of Mechanical Engineering and Materia ...