Progress to electrical properties of diamond-SiC composites under high pressure and high temperature

Polycrystalline diamond in the presence of silicon with different sintering times was investigated under high pressure and high temperature of 5.0 GPa and 1400 °C, respectively, using a multi-anvil apparatus. In this research, phase analysis demonstrated that the content of SiC increased and the amount of Si decreased clearly with the sintering time extending by X-ray diffraction (XRD). The characterization of the sintered body demonstrated that the electrical resistance decreased as the reaction time rose. Specimens with good conductivity of 17 Ω·cm−1 sintered for 20 min at 1400 °C under 5.0 GPa were successfully obtained. The measured Vickers hardness and thermal stability of the synthesized diamond-SiC composites in the present study were >40 GPa and 1450 K, respectively. •Diamond–SiC composites were investigated by sintering different times in the range of 1–20 min at 5.0 GPa and 1400 °C.•SiC was densely packed between the diamond’s grain boundaries, preventing the contact between the oxygen and diamond.•Extending the sintering time, and the graphitization of diamond occurred in low pressure zone are gradually in process.