Effect of SiC on densification, microstructure and mechanical properties of high entropy diboride (Ti<sub>0.2</sub>Zr<sub>0.2</sub>Hf<sub>0.2</sub>Nb<sub>0.2</sub>Ta<sub>0.2</sub>)B<sub>2</sub>
Creators
- 1. Slovak Acad Sci, CEMEA Ctr Adv Mat Applicat, Dubravska Cesta 9, Bratislava 84511, Slovakia
- 2. Slovak Acad Sci, Inst Inorgan Chem, Dubravska Cesta 9, Bratislava 84536, Slovakia
- 3. Inst Phys Mat, Czech Acad Sci, Zizkova 22, Brno 61600, Czech Republic
- 4. Inst Mat Res, Slovak Acad Sci, Watsonova 47, Kosice 04001, Slovakia
Description
Highly dense high entropy diboride (Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)B-2-SiC composites with different beta-SiC content (5, 10, 15, 20 and 25 vol%) were prepared by Spark Plasma Sintering (SPS) at 1900 degrees C. High-purity high entropy diboride (HEB) powder was synthesized using boro/carbothermal reduction of oxide precursors at 1800 degrees 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.m(1/2)), Young's modulus (495.3 +/- 0.3 GPa) and dynamic oxidation resistance (0.02 mg.cm(-2).s(-1)).
Files
bib-740093f4-cb34-4dc2-9a78-5e1392d583fe.txt
Files
(395 Bytes)
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