Journal Home > Volume 10 , Issue 1

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.


menu
Abstract
Full text
Outline
About this article

A new class of high-entropy M3B4 borides

Show Author's information Mingde QINQizhang YANYi LIUJian LUO( )
Department of NanoEngineering, Program of Materials Science and Engineering, University of California, San Diego, La Jolla, CA, 92093, USA

Abstract

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.

Keywords: high-entropy ceramics, high-entropy borides, reactive sintering, spark plasma sintering, Ta3B4-prototyped orthorhombic structure

References(40)

[1]
JW Yeh, SJ Lin, TS Chin, et al. Formation of simple crystal structures in Cu-Co-Ni-Cr-Al-Fe-Ti-V alloys with multiprincipal metallic elements. Metall Mat Trans A 2004, 35: 2533-2536.
[2]
B Cantor, ITH Chang, P Knight, et al. Microstructural development in equiatomic multicomponent alloys. Mater Sci Eng: A 2004, 375-377: 213-218.
[3]
DB Miracle, ON Senkov. A critical review of high entropy alloys and related concepts. Acta Mater 2017, 122: 448-511.
[4]
SC Jiang, T Hu, J Gild, et al. A new class of high-entropy perovskite oxides. Scripta Mater 2018, 142: 116-120.
[5]
J Gild, M Samiee, JL Braun, et al. High-entropy fluorite oxides. J Eur Ceram Soc 2018, 38: 3578-3584.
[6]
AJ Wright, QY Wang, ST Ko, et al. Size disorder as a descriptor for predicting reduced thermal conductivity in medium- and high-entropy pyrochlore oxides. Scripta Mater 2020, 181: 76-81.
[7]
CM Rost, E Sachet, T Borman, et al. Entropy-stabilized oxides. Nat Commun 2015, 6: 8485.
[8]
J Gild, YY Zhang, T Harrington, et al. High-entropy metal diborides: A new class of high-entropy materials and a new type of ultrahigh temperature ceramics. Sci Rep 2016, 6: 37946.
[9]
MD Qin, QZ Yan, HR Wang, et al. High-entropy monoborides: Towards superhard materials. Scripta Mater 2020, 189: 101-105.
[10]
PB Zhao, JP Zhu, YL Zhang, et al. A novel high-entropy monoboride (Mo0.2Ta0.2Ni0.2Cr0.2W0.2)B with superhardness and low thermal conductivity. Ceram Int 2020, 46: 26626-26631.
[11]
P Sarker, T Harrington, C Toher, et al. High-entropy high-hardness metal carbides discovered by entropy descriptors. Nat Commun 2018, 9: 4980.
[12]
TJ Harrington, J Gild, P Sarker, et al. Phase stability and mechanical properties of novel high entropy transition metal carbides. Acta Mater 2019, 166: 271-280.
[13]
XL Yan, L Constantin, YF Lu, et al. (Hf0.2Zr0.2Ta0.2Nb0.2Ti0.2)C high-entropy ceramics with low thermal conductivity. J Am Ceram Soc 2018, 101: 4486-4491.
[14]
J Gild, J Braun, K Kaufmann, et al. A high-entropy silicide: (Mo0.2Nb0.2Ta0.2Ti0.2W0.2)Si2. J Materiomics 2019, 5: 337-343.
[15]
Y Qin, JX Liu, F Li, et al. A high entropy silicide by reactive spark plasma sintering. J Adv Ceram 2019, 8: 148-152.
[16]
XQ Chen, YQ Wu. High-entropy transparent fluoride laser ceramics. J Am Ceram Soc 2020, 103: 750-756.
[17]
AJ Wright, QY Wang, CY Huang, et al. From high-entropy ceramics to compositionally-complex ceramics: A case study of fluorite oxides. J Eur Ceram Soc 2020, 40: 2120-2129.
[18]
AJ Wright, J Luo. A step forward from high-entropy ceramics to compositionally complex ceramics: A new perspective. J Mater Sci 2020, 55: 9812-9827.
[19]
Y Zhang, ZB Jiang, SK Sun, et al. Microstructure and mechanical properties of high-entropy borides derived from boro/carbothermal reduction. J Eur Ceram Soc 2019, 39: 3920-3924.
[20]
JF Gu, J Zou, SK Sun, et al. Dense and pure high-entropy metal diboride ceramics sintered from self-synthesized powders via boro/carbothermal reduction approach. Sci China Mater 2019, 62: 1898-1909.
[21]
J Gild, A Wright, K Quiambao-Tomko, et al. Thermal conductivity and hardness of three single-phase high-entropy metal diborides fabricated by borocarbothermal reduction and spark plasma sintering. Ceram Int 2020, 46: 6906-9613.
[22]
G Tallarita, R Licheri, S Garroni, et al. Novel processing route for the fabrication of bulk high-entropy metal diborides. Scripta Mater 2019, 158: 100-104.
[23]
G Tallarita, R Licheri, S Garroni, et al. High-entropy transition metal diborides by reactive and non-reactive spark plasma sintering: A comparative investigation. J Eur Ceram Soc 2020, 40: 942-952.
[24]
MD Qin, J Gild, HR Wang, et al. Dissolving and stabilizing soft WB2 and MoB2 phases into high-entropy borides via boron-metals reactive sintering to attain higher hardness. J Eur Ceram Soc 2020, 40: 4348-4353.
[25]
H Chen, ZF Zhao, HM Xiang, et al. Effect of reaction routes on the porosity and permeability of porous high entropy (Y0.2Yb0.2Sm0.2Nd0.2Eu0.2)B6 for transpiration cooling. J Mater Sci Technol 2020, 38: 80-85.
[26]
G Akopov, MT Yeung, RB Kaner. Rediscovering the crystal chemistry of borides. Adv Mater 2017, 29: 1604506.
[27]
E Rudy, S Windisch. Ternary Phase Equilibria in Transition Metal-Boron-Carbon-Silicon Systems, Part I. Related Binary Systems. Volume X. System V-B, Nb-B, and Ta-B. Air Force Materials Laboratory, Wright-Patterson Air Force Base, OH, 1966.
DOI
[28]
TK Yao, YC Wang, H Li, et al. A universal trend of structural, mechanical and electronic properties in transition metal (M=V, Nb, and Ta) borides: First-principle calculations. Comput Mater Sci 2012, 65: 302-308.
[29]
H Bolmgren, T Lundström, LE Tergenius, et al. The crystal structure of Ta5B6. J Less Common Met 1990, 161: 341-345.
[30]
KE Spear, PK Liao, JF Smith. The B-V (boron-vanadium) system. J Phase Equilibria 1987, 8: 447-454.
[31]
KE Spear, PW Gilles. Phase and structure relationships in the vanadium-boron system. High Temp Sci 1969, 1: 86-97.
[32]
S Okada, T Atoda, I Higashi. Structural investigation of Cr2B3, Cr3B4, and CrB by single-crystal diffractometry. J Solid State Chem 1987, 68: 61-67.
[33]
S Okada, K Hamano, T Lundström, et al. Crystal growth of the new compound Nb2B3, and the borides NbB, Nb5B6, Nb3B4, and NbB2, using the copper-flux method. AIP Conf Proc 1991, 231: 456-459.
[34]
S Okada, K Kudou, I Higashi, et al. Single crystals of TaB, Ta5B6, Ta3B4 and TAB2, as obtained from high-temperature metal solutions, and their properties. J Cryst Growth 1993, 128: 1120-1124.
[35]
E Rudy, S Windisch. Ternary Phase Equilibria in Transition Metal-Boron-Carbon-Silicon Systems. Part I. Related Binary Systems. Volume III. Systems Mo-B and W-B. Air Force Materials Laboratory, Wright-Patterson Air Force Base, OH, 1966.
DOI
[36]
J Schmidt, M Boehling, U Burkhardt, et al. Preparation of titanium diboride TiB2 by spark plasma sintering at slow heating rate. Sci Technol Adv Mater 2007, 8: 376-382.
[37]
SL Ran, L Zhang, O van der Biest, et al. Pulsed electric current, in situ synthesis and sintering of textured TiB2 ceramics. J Eur Ceram Soc 2010, 30: 1043-1047.
[38]
AA Ivankov. Handbook of Hardness Data. Kiev: Naukova Dumka, 1968.
[39]
MD Qin, J Gild, CZ Hu, et al. Dual-phase high-entropy ultra-high temperature ceramics. J Eur Ceram Soc 2020, 40: 5037-5050.
[40]
JX Liu, XQ Shen, Y Wu, et al. Mechanical properties of hot-pressed high-entropy diboride-based ceramics. J Adv Ceram 2020, 9: 503-510.
Publication history
Copyright
Acknowledgements
Rights and permissions

Publication history

Received: 18 September 2020
Revised: 29 October 2020
Accepted: 09 November 2020
Published: 08 December 2020
Issue date: February 2021

Copyright

© The Author(s) 2020

Acknowledgements

This work is partially supported by an office of Naval Research MURI Program (Grant No. N00014-15-1-2863). Qizhang YAN and Jian LUO also acknowledge partial support from the Air Force Office of Scientific Research (Grant No. FA9550-19-1-01327) for the microscopy work.

Rights and permissions

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.

The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.

Return