Mechanical characteristics of dual-phase medium-entropy boride/carbide ceramics synthesized through SPS

Material scientists constantly look for new compounds with exceptional properties to meet the ever-changing technology and industry needs. Hereby, the dual-phase medium-entropy ceramics have fabricated by employing high-energy ball milling (HEBM) and spark plasma sintering (SPS) techniques on commercial boride and carbide powders of IVB group metals. The boride and carbide powders have undergone 3-hour milling in a planetary ball mill, followed by SPS processing at 1800 degrees C and 2000 degrees C under 30 MPa uniaxial pressure for 10 min. The milled powders and SPS'ed ceramics have been characterized, focusing on composition, density, and microstructure using X-ray diffractometry (XRD) and scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDS). Microhardness and sliding wear tests have also been performed on the SPS'ed ceramics. The systematic analysis of the characterization results has revealed that the microstructural evolution and mechanical properties of the dual-phase ceramics have developed to a comparable level with the single-phase ceramics, regardless of the sintering temperature. In fact, the dual-phase ceramics sintered at 1800 degrees C come to the forefront due to the superior hardness and fracture toughness values (similar to 16 GPa and similar to 5.4 MPa.m1/2).