Two-Step Synthesis Process for High-Entropy Diboride Powders
High-entropy diboride powders were produced by a two-step synthesis process consisting of boro/carbothermal reduction followed by solid solution formation. Nominally phase-pure (Hf,Zr,Ti,Ta,Nb)B2 in a single-phase hexagonal structure had an average particle size of just over 400 nm and contained 0.3 wt% carbon and 0.3 wt% oxygen. The fine particle size was due to the use of high-energy ball milling prior to boro/carbothermal reduction, which led to a relatively low synthesis temperature of 1650°C. Oxygen and carbon contents were minimized by completion of the boro/carbothermal reduction reactions under vacuum. This is the first report of synthesis of a nominally phase pure high-entropy diboride powder from oxides using a two-step process.
L. Feng et al., "Two-Step Synthesis Process for High-Entropy Diboride Powders," Journal of the American Ceramic Society, vol. 103, no. 2, pp. 724 - 730, Blackwell Publishing Inc., Feb 2020.
The definitive version is available at https://doi.org/10.1111/jace.16801
Materials Science and Engineering
Keywords and Phrases
Boro/Carbothermal Reduction; High-Entropy Diboride; Solid Solution; Synthesis
International Standard Serial Number (ISSN)
Article - Journal
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01 Feb 2020