Metal deficient AlB$_{2}$-type (Ti$_{0.2}$Zr$_{0.2}$Hf$_{0.2}$Nb$_{0.2}$Ta$_{0.2}$)$_{1-δ}$B$_{2}$ high-entropy diborides with high hardness

Wuzhang Yang; Qinqing Zhu; Guorui Xiao; Zhi Ren

doi:10.1016/j.ceramint.2022.11.100

paper

Metal deficient AlB $_{2}$ -type (Ti $_{0.2}$ Zr $_{0.2}$ Hf $_{0.2}$ Nb $_{0.2}$ Ta $_{0.2}$ ) $_{1 - δ}$ B $_{2}$ high-entropy diborides with high hardness

arXiv:2302.07418 · doi:10.1016/j.ceramint.2022.11.100

Abstract

We report the synthesis and characterization of metal deficient (Ti $_{0.2}$ Zr $_{0.2}$ Hf $_{0.2}$ Nb $_{0.2}$ Ta $_{0.2}$ ) $_{1 - δ}$ B $_{2}$ high-entropy diborides (HEBs). A single homogeneous AlB $_{2}$ -type phase is successfully obtained over the $δ$ range of 0.03 $\leq$ $δ$ $\leq$ 0.18. With increasing $δ$ , the unit-cell volume exhibits a nonmonotonic variation with a maximum at $δ$ = 0.07. These metal-deficient HEBs possess high Vickers hardness of 16.6-18.9 GPa at a load of 9.8 N and their phase stability is attributed to the increased mixing entropy. Our results not only present the first series of metal-deficient AlB $_{2}$ -type HEBs, but also suggest the existence of similar multicomponent diborides.

arXiv comment7 pages, 4 figures

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Metal deficient AlB2​-type (Ti0.2​Zr0.2​Hf0.2​Nb0.2​Ta0.2​)1−δ​B2​ high-entropy diborides with high hardness

Abstract

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Cited by in corpus (1)

Metal deficient AlB $_{2}$ -type (Ti $_{0.2}$ Zr $_{0.2}$ Hf $_{0.2}$ Nb $_{0.2}$ Ta $_{0.2}$ ) $_{1 - δ}$ B $_{2}$ high-entropy diborides with high hardness