Non-stoichiometry of (TiZrHfVNbTa)C  and its significance to the microstructure and mechanical properties

Zhang, Wen; Chen, Lei; Lu, Wenyu; Huo, Sijia; Wei, Boxin; Wang, Yujin; Zhang, Yu

doi:10.1016/j.jeurceramsoc.2022.07.007

Cited by 23 publications

(25 citation statements)

References 43 publications

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“…Moreover, X-ray photoelectron spectroscopy (XPS) characterizations in Ref. [19] illustrate that the Ta binding energy decreases with the decline in the carbon stoichiometry, indicating the decrease in valence of cations, which confirms the generation of the carbon vacancies for (TiZrHfVNbTa)C 0.6 .…”

Section: Resultsmentioning

confidence: 83%

“…) where x is chosen as 0.5, 0.6, 0.68, 0.74, 0.81, 0.87, 0.94, and 1.0. According to the previous results of carbon and oxygen contents for all compositions [19], the calculated chemical formulas are (TiZrHfVNbTa)C 0.60 , (TiZrHfVNbTa)C 0.71 , (TiZrHfVNbTa)C 0.79 , (TiZrHf-VNbTa)C 0.84 , (TiZrHfVNbTa)C 0.91 , (TiZrHfVNbTa)C 0.95 , (TiZrHfVNbTa)C 0.98 , and (TiZrHfVNbTa)C 1.00 , respectively. Hence, (TiZrHfVNbTa)C 0.6 is chosen as the target system for subsequent study due to the highest carbon vacancy concentration among all systems.…”

Section: Introduction mentioning

confidence: 76%

“…The detailed processing methods including carbothermal reduction reaction (1500 ℃ for 1 h) and pressureless sintering (2100-2400 ℃) are similar to those reported in Ref. [19]. For simplification, (TiZrHfVNbTa)C 0.60 @2150 represents that this composition is pressureless-sintered at 2150 ℃ for 1 h.…”

Section: Introduction mentioning

confidence: 87%

“…It has been reported that senary (TiZrHfVNbTa)C x exhibit fine microstructure and excellent comprehensive mechanical properties [18]. Moreover, the mechanical properties of (TiZrHfVNbTa)C x can be continuously adjusted by tailoring the carbon stoichiometry [19]. Thus, in the present work, the thermal properties of (TiZrHfVNbTa)C x (x = 0.6-1) were studied in detail, and the influence of the carbon vacancy on the thermal conductivity was emphatically discussed.…”

Section: Introduction mentioning

confidence: 90%

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Low thermal conductivity of dense (TiZrHfVNbTa)C_xhigh-entropy carbides by tailoring carbon stoichiometry

Chen¹,

Zhou²,

Lu³

et al. 2023

Journal of Advanced Ceramics

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Transition metal carbides are promising candidates for thermal protection materials due to their high melting points and excellent mechanical properties. However, the relatively high thermal conductivity is still a major obstacle to its application in an ultra-high-temperature insulation system. In this work, the low thermal conductivity of dense (TiZrHfVNbTa)C x (x = 0.6-1) high-entropy carbides has been realized by adjusting the carbon stoichiometry. The thermal conductivity gradually decreases from 10.6 W•m −1 •K −1 at room temperature to 6.4 W•m −1 •K −1 with carbon vacancies increasing. Due to enhanced scattering of phonons and electrons by the carbon vacancies, nearly full-dense (97.9%) (TiZrHfVNbTa)C 0.6 possesses low thermal conductivity of 6.4 W•m −1 •K −1 , thermal diffusivity of 2.3 mm 2 •s −1 , as well as electrical resistivity of 165.5 μΩ•cm. The thermal conductivity of (TiZrHfVNbTa)C 0.6 is lower than that of other quaternary and quinary high-entropy carbide ceramics, even if taking the difference of porosity into account in some cases, which is mainly attributed to compositional complexity and carbon vacancies. This provides a promising route to reduce the thermal conductivity of high-entropy carbides by increasing the number of metallic elements and carbon vacancies.

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Section: Resultsmentioning

confidence: 83%

Section: Introduction mentioning

confidence: 76%

Section: Introduction mentioning

confidence: 87%

Section: Introduction mentioning

confidence: 90%

See 2 more Smart Citations

Low thermal conductivity of dense (TiZrHfVNbTa)C_xhigh-entropy carbides by tailoring carbon stoichiometry

Chen¹,

Zhou²,

Lu³

et al. 2023

Journal of Advanced Ceramics

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“…Accordingly, the Vickers indentation fracture toughness of HECN0.8 ceramic is 8.72±0.69 MPa•m 1/2 (higher than the SENB one), which may be due to the Vickers indentation method only represents the fracture toughness of the local region of a ceramic material, and the obtained data are relatively discrete, leading to larger test results, while the SENB method can better reflect the fracture toughness of a ceramic material as a whole. To better demonstrate the outstanding mechanical properties of the HECN0.8 ceramic, the comparison of mechanical performance including flexural strength and fracture toughness (SENB) among other HE ceramics [12], [14], [47][48][49][50][51][52][53][54] published recently is depicted in Fig. 10(a).…”

Section: Mechanical Properties Of Hecn08 Ceramicmentioning

confidence: 99%

Fabrication of multi-anionic high-entropy carbonitride ultra-high-temperature ceramics by a green and low-cost process with excellent mechanical properties

Xia¹,

Dong²,

Xin³

et al. 2023

Journal of Advanced Ceramics

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As a new category of ultra-high temperature ceramics (UHTCs), multi-anionic highentropy (HE) carbonitride UHTCs are expected to have better comprehensive performances than conventional UHTCs. However, how to realize the green and low-cost synthesis of high-quality multi-anionic HE carbonitride UHTC powders and prepare bulk ceramics with excellent mechanical properties still faces great challenges. In this work, a green, low-cost and controllable preparation process of (Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)CxN1-x powders is achieved by a sol-gel combined with carbothermal reduction/nitridation method for the first time. The as-synthesized (Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)CxN1-x powders possess high compositional uniformity and controllable particle size. In addition, the obtained bulk ceramics prepared at 1800 ℃ exhibit a superior fracture toughness of 5.39±0.16 MPa•m 1/2 , high nanohardness of 35.75±1.23 GPa, elastic modulus of 566.70±8.68 GPa and flexural strength of 487±41 MPa. This study provides a feasible strategy for preparing high-performance HE carbonitride ceramics in a more environmentally friendly and economical manner.

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Role of carbon vacancies in determining the structural, mechanical, and thermodynamic properties of (HfTaZrNb)C1-x high entropy carbides: a first-principles study

Bai,

Liang,

et al. 2024

J Mater Sci

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Non-stoichiometry of (TiZrHfVNbTa)C and its significance to the microstructure and mechanical properties

Cited by 23 publications

References 43 publications

Low thermal conductivity of dense (TiZrHfVNbTa)C_xhigh-entropy carbides by tailoring carbon stoichiometry

Low thermal conductivity of dense (TiZrHfVNbTa)C_xhigh-entropy carbides by tailoring carbon stoichiometry

Fabrication of multi-anionic high-entropy carbonitride ultra-high-temperature ceramics by a green and low-cost process with excellent mechanical properties

Role of carbon vacancies in determining the structural, mechanical, and thermodynamic properties of (HfTaZrNb)C1-x high entropy carbides: a first-principles study

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Non-stoichiometry of (TiZrHfVNbTa)C and its significance to the microstructure and mechanical properties

Cited by 23 publications

References 43 publications

Low thermal conductivity of dense (TiZrHfVNbTa)Cxhigh-entropy carbides by tailoring carbon stoichiometry

Low thermal conductivity of dense (TiZrHfVNbTa)Cxhigh-entropy carbides by tailoring carbon stoichiometry

Fabrication of multi-anionic high-entropy carbonitride ultra-high-temperature ceramics by a green and low-cost process with excellent mechanical properties

Role of carbon vacancies in determining the structural, mechanical, and thermodynamic properties of (HfTaZrNb)C1-x high entropy carbides: a first-principles study

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Low thermal conductivity of dense (TiZrHfVNbTa)C_xhigh-entropy carbides by tailoring carbon stoichiometry

Low thermal conductivity of dense (TiZrHfVNbTa)C_xhigh-entropy carbides by tailoring carbon stoichiometry