Microstructure and mechanical properties of high entropy (MoTaTiVW)C5 ceramics toughened with silicon carbide whisker

High entropy carbide ceramics have attracted much attention because of their high hardness and chemical inertness, but the relatively low fracture toughness limits their actual industrial applications. In this work, high entropy (MoTaTiVW)C5 ceramics reinforced with silicon carbide whisker (SiCw) were fabricated with spark plasma sintering. The effects of SiCw contents and sintering temperatures on the microstructure and mechanical properties of (MoTaTiVW)C5 have been studied. The outcomes show that by optimizing the sintering temperature, a dense microstructure with intact SiCw were obtained which could fully utilize the toughening effect of the SiCw and thus exhibits an enhanced mechanical property. Additionally, the presence of solid solution oxide particles in the sintered bulks is also beneficial for the improved toughness. The sample with 5 wt% SiCw sintered at 1700 °C exhibited higher hardness of 19.63 GPa and fracture toughness of 6.26 MPa m1/2, which is attributed to the combined toughening effects (crack deflection, crack bridging, and whisker/particle extraction) of SiCw and oxide particles. The findings contribute to the development of advanced ceramic materials with improved mechanical properties for various applications.