Improved densification and hardness of high-entropy diboride ceramics from fine powders synthesized via borothermal reduction process. Issue 9 (15th June 2020)

• Record Type: Journal Article
• Authors: Zhang, Yan; Sun, Shi-Kuan; Zhang, Wei; You, Yang; Guo, Wei-Ming; Chen, Zhi-Wei; Yuan, Jin-Hao; Lin, Hua-Tay
• Is Part Of: Ceramics international. Volume 46:Issue 9(2020)
• Page Start: 14299
• Page End: 14303
• Publication Date: 2020-06-15
• Subjects: High-entropy diboride ceramics -- Borothermal reduction -- Purity -- Densification; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2020.02.214
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: High-entropy boride ceramics of (Zr0.2 Ta0.2 Ti0.2 Nb0.2 Hf0.2 )B2 and (Zr0.2 W0.2 Ti0.2 Mo0.2 Hf0.2 )B2 were prepared by combining powder synthesis via borothermal reduction process at 1600 °C and subsequent ceramic densification by spark plasma sintering at 2000 °C in argon. High-entropy diboride powdered products exhibited ultra-fine particle size (<0.5 μm) after borothermal reduction. (Zr0.2 Ta0.2 Ti0.2 Nb0.2 Hf0.2 )B2 ceramic with the single phase was obtained after sintering. However, the minor phase with the nominal WB composition was detected in (Zr0.2 W0.2 Ti0.2 Mo0.2 Hf0.2 )B2 ceramic. (Zr0.2 W0.2 Ti0.2 Mo0.2 Hf0.2 )B2 ceramic exhibited a high relative density associated with the high hardness of 27.7 GPa, which were higher than those measured for (Zr0.2 Ta0.2 Ti0.2 Nb0.2 Hf0.2 )B2 ceramics (94.0% in relative density and 16.4 GPa in hardness) or the reported values (~92% in relative densities and 17.5–23.7 GPa in hardness) of other high-entropy boride ceramics.