Effect of SiC on densification, microstructure and mechanical properties of high entropy diboride (Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)B2

• DOI: 10.1016/j.jeurceramsoc.2023.12.072
• Publication Date: 2023-12-24T06:41:51Z
• Authors: Vasanthakumar Kom...; Hakan Ünsal; Zdeněk Chlup; Monika Tatarková; Alexandra Kovalčí...; Inga Zhukova; Naser Hosseini; Michal Hičák; Ivo Dlouhý; Peter Tatarko

Highly dense high entropy diboride (Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)B2-SiC composites with different β-SiC content (5, 10, 15, 20 and 25 vol.%) were synthesized using ball milling followed by Spark Plasma Sintering (SPS) at 1900°C. High-purity (HEB) powder was boro/carbothermal reduction of oxide precursors 1800°C. X-ray diffraction patterns the powders sintered compacts HEB showed a single solid solution hexagonal AlB2 structure without any residual impurities. energy dispersive Spectroscopy (EDS) mapping results indicated uniform elemental distribution transition metals in phase. The addition SiC improved densification HEB-SiC composites. composite vol.% exhibited unique combination mechanical properties, such as superior Vickers hardness (22.28 ± 0.25 GPa), flexural strength (750. 21 43.23 MPa), indentation fracture toughness (4.12 0.2 MPa.m1/2), Young's modulus (495.3 0.3 GPa) dynamic oxidation resistance (0.02 mg.cm-2.s-1).