A new class of high-entropy M3B4 borides

• 作者: Mingde QIN Qizhang YAN Yi LIU Jian LUO
• 来源期刊: 先进陶瓷（英文版）
• 年，卷（期）: 2021,（1）
• 所属期刊栏目: Research Article
• 页码范围: 166-172
• 页数: 7页
• 语种: 英文

摘要

A new class of high-entropy M3B4 borides of the Ta3B4-prototyped orthorhombic structure has been synthesized in the bulk form for the first time. Specimens with compositions of (V0.2Cr0.2Nb0.2Mo0.2Ta0.2)3B4 and (V0.2Cr0.2Nb0.2Ta0.2W0.2)3B4 were fabricated via reactive spark plasma sintering of high-energy-ball-milled elemental boron and metal precursors. The sintered specimens were ～98.7％ in relative densities with virtually no oxide contamination, albeit the presence of minor (4–5 vol％) secondary high-entropy M5B6 phases. Despite that Mo3B4 or W3B4 are not stable phase, 20％ of Mo3B4 and W3B4 can be stabilized into the high-entropy M3B4 borides. Vickers hardness was measured to be 18.6 and 19.8 GPa at a standard load of 9.8 N. This work has further expanded the family of different structures of high-entropy ceramics reported to date.