Mechanical and physical behavior of spark plasma sintered ZrC–ZrB2–SiC composites

The effects of compositions on mechanical, thermal and electrical properties of ZrC–ZrB2–SiC composites were examined. The composites were consolidated by spark plasma sintering. The elastic moduli of the composites were measured using the longitudinal and transverse soundwave velocities measured, whereas the hardness and fracture toughness of the composites were determined using an indentation measurement. The results indicated that the shear modulus was in the range 180–225 GPa and the Young's modulus is in the range 435–517 GPa. The ranges of hardness and fracture toughness values were measured to be 18.8–21.5 GPa, and 4.6–6.1 MPa m1/2, respectively. On the other hand, the thermal and electrical conductivities of the ZrC–ZrB2–SiC composites were measured at room temperature by a nanoflash technique and a current–voltage method, respectively. The thermal conductivities for the composites were in the range 38.25–92.85 W m−1 K−1. The electrical conductivities of the composites were in the range 0.916–4.521 × 104 (Ω cm)−1.