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

0585151 - ÚFM 2025 RIV GB eng J - Journal Article
Kombamuthu, V. - Ünsal, H. - Chlup, Zdeněk - Tatarková, M. - Kovalčíková, A. - Zhukova, I. - Hosseini, N. - Hičák, M. - Dlouhý, Ivo - Tatarko, P.
Effect of SiC on densification, microstructure and mechanical properties of high entropy diboride (Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)B2.
Journal of the European Ceramic Society. Roč. 44, č. 9 (2024), s. 5358-5369. ISSN 0955-2219. E-ISSN 1873-619X
Institutional support: RVO:68081723
Keywords : Boro/carbothermal reduction * High-entropy diborides * Mechanical properties * Silicon carbide * Spark plasma sintering
OECD category: Ceramics
Impact factor: 5.7, year: 2022
Method of publishing: Open access
https://www.sciencedirect.com/science/article/pii/S0955221923010877?via%3Dihub

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 prepared by Spark Plasma Sintering (SPS) at 1900 °C. High-purity high entropy diboride (HEB) powder was synthesized using boro/carbothermal reduction of oxide precursors at 1800 °C. X-ray diffraction patterns of the synthesized powders and sintered compacts of HEB showed a single solid solution with hexagonal AlB2 structure without any residual oxide impurities. Energy Dispersive X-ray Spectroscopy (EDS) mapping results indicated the uniform elemental distribution of transition metals in the HEB phase. The addition of SiC improved the densification of HEB-SiC composites. The composite with 20 vol% SiC exhibited a unique combination of 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) and dynamic oxidation resistance (0.02 mg.cm−2.s−1).
Permanent Link: https://hdl.handle.net/11104/0352904