Improved densification and hardness of high-entropy diboride ceramics from fine powders synthesized via borothermal reduction process

Zhang, Yan; Sun, Shi‐Kuan; Zhang, Wei; You, Yang; Guo, Wei‐Ming; Chen, Zhiwei; Yuan, Jinhao; Lin, Hua‐Tay

doi:10.1016/j.ceramint.2020.02.214

Cited by 67 publications

(34 citation statements)

References 29 publications

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“…For the AlB 2 structure‐type solid solutions, the solid solution of (Ti,W,Cr)B 2 was previously reported 42 . In the case of high‐entropy diboride ceramics, solid solutions containing Ti, Mo, and W could be formed 43,44 . On the other hand, ternary phases containing Ti, Mo, and W were not observed by careful examination of XRD patterns.…”

Section: Resultsmentioning

confidence: 96%

Dense and core‐rim structured B₄C‐TiB₂ ceramics with Mo‐Co‐WC additive

et al. 2021

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B4C‐TiB2 ceramics (TiB2 ranging 5~70 vol%) with Mo‐Co‐WC as the sintering additive were prepared by spark plasma sintering. In comparison with B4C‐TiB2 without additive, the enhanced densification was evident in the sintered specimen with Mo‐Co‐WC additive. Core‐rim structured grain was observed around TiB2 grains. The interface of the rim between TiB2 and B4C phases demonstrated different feature: the inner borderline of the rim exhibited a smooth feature, whereas a sharp curved grain boundary was observed between the rim and the B4C grain. The formation mechanism is discussed: the epitaxial growth of (Ti,Mo,W)B2 rim around the TiB2 core may occur as a result of the solid solution and dissolution‐precipitation between TiB2 phase and the sintering additive. It was revealed that the fracture toughness increased as the content of TiB2 content increased, alongside the decreased hardness. B4C‐30 vol% TiB2 specimen demonstrated the optimal combination of mechanical properties, reaching Vickers hardness of 24.3 GPa and fracture toughness of 3.33 MPa·m1/2.

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Section: Resultsmentioning

confidence: 96%

Dense and core‐rim structured B₄C‐TiB₂ ceramics with Mo‐Co‐WC additive

et al. 2021

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“…To achieve such a goal, various methods have been used to synthesize ultrafine high-entropy carbide and boride powders. Moskovskikh et al [ [130,[135][136][137].…”

Section: Powdersmentioning

confidence: 99%

High-entropy ceramics: Present status, challenges, and a look forward

et al. 2021

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High-entropy ceramics (HECs) are solid solutions of inorganic compounds with one or more Wyckoff sites shared by equal or near-equal atomic ratios of multi-principal elements. Although in the infant stage, the emerging of this new family of materials has brought new opportunities for material design and property tailoring. Distinct from metals, the diversity in crystal structure and electronic structure of ceramics provides huge space for properties tuning through band structure engineering and phonon engineering. Aside from strengthening, hardening, and low thermal conductivity that have already been found in high-entropy alloys, new properties like colossal dielectric constant, super ionic conductivity, severe anisotropic thermal expansion coefficient, strong electromagnetic wave absorption, etc., have been discovered in HECs. As a response to the rapid development in this nascent field, this article gives a comprehensive review on the structure features, theoretical methods for stability and property prediction, processing routes, novel properties, and prospective applications of HECs. The challenges on processing, characterization, and property predictions are also emphasized. Finally, future directions for new material exploration, novel processing, fundamental understanding, in-depth characterization, and database assessments are given.

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“…Wei et al [15] [16]. A series of studies have demonstrated that highentropy ceramic powders prepared by using the boro/carbothermal reduction approach exhibited better sintering behavior than the commercial powders [17][18][19]. Huo et al showed that a (Ti,Zr)B 2 -(Zr,Ti)C composite fabricated by reactive hot pressing can re ne the grain size and improve the mechanical properties [20,21].…”

Section: Introductionmentioning

confidence: 99%