Sinterability studies of monolithic chromium diboride (CrB2) by spark plasma sintering

• Three different stages were observed during the densification of CrB2 by spark plasma sintering route.
• CrB2 of relative density close to 95%ρth was obtained in just 1 min of operation at 1900 °C under a mechanical pressure of 70 MPa.
• Applied mechanical pressure effects dominate at lower sintering temperatures than at higher processing temperatures.

Spark plasma sintering (SPS) experiments were conducted to investigate the effect of the processing parameters such as temperature, mechanical pressure and dwell time on densification behavior of monolithic chromium diboride. The sintering experiments were performed at different temperatures ranging from 1100 °C to 1900 °C under the mechanical pressure of 30 MPa–70 MPa for 1 min–15 min duration. The onset temperature for the densification of CrB2 is observed to be 1300 °C at 50 MPa. High dense chromium diboride (98.4%ρth) compact was obtained when processed at 1900 °C under a mechanical pressure of 70 MPa for 15 min duration. Hardness and fracture toughness of high density monolithic CrB2 (98.4%ρth) sample were measured to be 15.89 ± 1.3 GPa and 1.8 ± 0.14 MPa·m1/2 respectively.