Influence of uniaxial strains on the mechanical properties of transition metal borides X2B, XB and XB2 (X = Cr, Mo, W)

Zhu, Haiyan; Shi, Lei; Li, Shuaiqi; Duan, Yufeng; Xia, Wangsuo; Wang, Ying

doi:10.1016/j.physb.2018.09.008

Cited by 8 publications

(5 citation statements)

References 41 publications

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“…The optimized lattice constants a = 5.128 Å and c = 4.287 Å are in good agreement with the previously reported results a = 5.125 Å and c = 4.276 Å. [ 18,19 ] The cohesive energy ( E coh ) and formation enthalpy ( E eff ) are given by

E_{coh} = \frac{1}{x + y} (E_{total} - x E_{Cr}^{atom} - y E_{normalB}^{atom})

E_{eff} = \frac{1}{x + y} (E_{total} - x E_{Cr}^{normalg} - y E_{normalB}^{normalg})

…”

Section: Resultssupporting

confidence: 89%

“…[ 20 ] Table 1 shows the calculated elastic constants C ij , bulk modulus( B ), shear modulus ( G ), Young's modulus ( E ), and Poisson's ratio ( σ ) at 0 GPa of Cr 2 B, which are in consistent with the available calculations. [ 19 ] Figure 2 shows the pressure dependences of elastic constants of Cr 2 B. As shown, the larger values of C 11 than C 33 under pressures indicate this structure is more easily compressible along the [001] direction than along the [100] direction.…”

Section: Resultsmentioning

confidence: 99%

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Physical Properties and Electronic Structure of Cr₂B Under Pressure

Zhang

Liu

Zhao

et al. 2020

Physica Status Solidi (b)

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The physical properties of Cr2B with I4/m symmetry under pressure are investigated by the first‐principles method. With the increase in pressure, the hardness decreases first and then slightly increases, whereas the bulk modulus, shear modulus, Young's modulus, fracture toughness, minimum thermal conductivity, and Debye temperature monotonically increase. Pressure induces the transition from brittleness to toughness at ≈30 GPa. When P > 30 GPa, the hardness and toughness increase simultaneously with pressure. The analysis of electronic structure indicates that the variation of BB covalent bonds may be responsible for the abnormous increase in hardness when P > 30 GPa.

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E_{coh} = \frac{1}{x + y} (E_{total} - x E_{Cr}^{atom} - y E_{normalB}^{atom})

E_{eff} = \frac{1}{x + y} (E_{total} - x E_{Cr}^{normalg} - y E_{normalB}^{normalg})

…”

Section: Resultssupporting

confidence: 89%

Section: Resultsmentioning

confidence: 99%

Physical Properties and Electronic Structure of Cr₂B Under Pressure

Zhang

Liu

Zhao

et al. 2020

Physica Status Solidi (b)

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“…Generally, due to solid-solution strengthening, the hardness of the high-entropy ceramic is usually slightly higher than the estimated one calculated by rule-of-mixture law. Moreover, a minor amount of P6 3 /mmc (194)-WB 2 grains with high-hardness (26.8 GPa) [36] were precipitated in the as-sintered MeB 2 -SiC ceramic, which may also increase the hardness of the ceramic. However, in the current study, the measured hardness (19.74 ± 0.8 GPa) is slightly lower than the estimated one (21.26 GPa).…”

Section: Mechanical and Oxidation Properties Of The Meb 2 -Sic Ceramicmentioning

confidence: 99%

A Novel Preparation Method of (Ti,Zr,Nb,Mo,W)B2-SiC Composite Ceramic Based on Reactive Sintering of Pre-Alloyed Metals

Zu,

Wang,

Tian

et al. 2023

Crystals

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High-entropy diboride-based (MeB2-based) ceramics are promising high-temperature structural materials because of their excellent mechanical properties, high-temperature stability, and oxidation resistance. In order to achieve low-temperature sintering of the high-entropy ceramics, a novel preparation method of high-entropy (Ti,Zr,Nb,Mo,W)B2-SiC ceramics based on reactive sintering of pre-alloyed solid-solution metals and nonmetals of Si, C, B4C was conducted in the current work. Mechanical alloying behavior of the mixed metal powders, as well as the phase composition, microstructure, mechanical properties, and oxidation behavior of the as-sintered MeB2-SiC ceramic were investigated. The XRD, SEM, and EPMA results indicated that the primary MeB2 solid-solution and SiC phases could be successfully formed during reactive sintering at a relatively low temperature of 1650 °C. The as-sintered MeB2-SiC ceramics had a high relative density of 97.8% and high mechanical properties (hardness of 19.74 ± 0.8 GPa, flexure strength of 533 ± 38 MPa, and fracture toughness of 6.01 ± 0.77 MPa·m1/2). Combining the oxidation behavior and microstructure evolution of the oxidation layer, a continuous and relatively dense MeOx-SiO2 oxidation layer was gradually formed and covered on the external surface, leading to decelerating oxidation behavior after an oxidation exposure time of 10 min.

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“…Compounds consisting of transition metals (TMs) and light elements such as B, C, and N have been identified as potential new type of superhard materials due to their excellent physical properties, such as electrical conductivity, high incompressibility, high shear strength, and exceptionally high hardness 1–3 . Among them, transition metal borides (TMBs), which can be synthesized at ambient pressure and therefore generally reduce the production costs, have attracted much attention 4–7 . In recent years, efforts have been made on transition metal diboride (TMB 2 ) (TM = Re, Os, Ru, W, etc.)…”

Section: Introductionmentioning

confidence: 99%

“…[1][2][3] Among them, transition metal borides (TMBs), which can be synthesized at ambient pressure and therefore generally reduce the production costs, have attracted much attention. [4][5][6][7] In recent years, efforts have been made on transition metal diboride (TMB 2 ) (TM = Re, Os, Ru, W, etc.) materials, which have been proven to have high hardness both theoretically and experimentally.…”

Section: Introductionmentioning

confidence: 99%

Thermal stability of ReB₂‐type transition metal diborides

Liang

Lin

2023

J Am Ceram Soc.

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The thermal stability of metastable ReB2‐type transition metal diborides (TMB2), which are considered as new type of superhard material, is of vital importance to obtain bulk samples. In the present work, thermal stability of four kinds of ReB2‐type TMB2 powders, ReB2, OsB2, Os1–xRexB2, and Os1‐xWxB2, were synthesized with varied transition metal (TM)‐to‐B molar ratio by mechanochemical methods and the subsequent annealing was compared. The as‐synthesized powders were then consolidated using a pressureless sintering technique. The results showed that the B content required to obtain the pure hexagonal ReB2‐type Os1–x(TM)xB2 phase varied, which indicated different thermal stabilities, such as OsB2 < Os0.1W0.1B2 < Os0.9Re0.1B2 < Os0.8W0.2B2 < ReB2 < Os0.6W0.4B2 and Os0.5W0.5B2. Among them, Os0.6W0.4B2 and Os0.5W0.5B2 were found to be relatively thermally stable and could be synthesized with a stoichiometric molar ratio of (Os + W):B = 1:2. It was also found that the thermal stability of TMB2 with a hexagonal ReB2 structure could be mainly governed by the length of lattice constant c. The results have guiding significance for the design and preparation of new type of TM borides. In addition, the hardness of TMB2 can be increased by tailoring the B content in the raw materials more precisely.

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Influence of uniaxial strains on the mechanical properties of transition metal borides X2B, XB and XB2 (X = Cr, Mo, W)

Cited by 8 publications

References 41 publications

Physical Properties and Electronic Structure of Cr₂B Under Pressure

Physical Properties and Electronic Structure of Cr₂B Under Pressure

A Novel Preparation Method of (Ti,Zr,Nb,Mo,W)B2-SiC Composite Ceramic Based on Reactive Sintering of Pre-Alloyed Metals

Thermal stability of ReB₂‐type transition metal diborides

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Influence of uniaxial strains on the mechanical properties of transition metal borides X2B, XB and XB2 (X = Cr, Mo, W)

Cited by 8 publications

References 41 publications

Physical Properties and Electronic Structure of Cr2B Under Pressure

Physical Properties and Electronic Structure of Cr2B Under Pressure

A Novel Preparation Method of (Ti,Zr,Nb,Mo,W)B2-SiC Composite Ceramic Based on Reactive Sintering of Pre-Alloyed Metals

Thermal stability of ReB2‐type transition metal diborides

Contact Info

Product

Resources

About

Influence of uniaxial strains on the mechanical properties of transition metal borides X2B, XB and XB2 (X = Cr, Mo, W)

Physical Properties and Electronic Structure of Cr₂B Under Pressure

Physical Properties and Electronic Structure of Cr₂B Under Pressure

Thermal stability of ReB₂‐type transition metal diborides