Effect of high temperature preoxidation treatment on the oxidation behavior of MoSi2- and WSi2–Al2O3 composites

Yakaboylu, Gunes A.; Yumak, Tuğrul; Sabolsky, Katarzyna; Sabolsky, Edward M.

doi:10.1016/j.jallcom.2019.152499

Cited by 14 publications

(5 citation statements)

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“…As a result, gradient multilayer SiC/SiBCN ceramic hybrid aerogel with excellent mechanical properties was successfully prepared. shown below [45,46]:…”

Section: Resultsmentioning

confidence: 99%

Gradient multi-layer ceramic fiber aerogel: Fabrication, anti-oxidation and thermal insulation

Zhong

Liu

et al. 2022

Preprint

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Aerogel is widely used in the field of thermal insulation. However, they exhibit brittleness and a dramatic increase in radiative heat transfer and effective thermal conductivity at high temperatures. Fiber composite aerogel achieved great progress, but the homogeneous structure hardly allowed heat convection, heat conduction, and heat radiation to be controlled simultaneously. In this paper, inspired by bamboo's multilayer and gradient structure, SiC fiber was prepared by electrostatic spinning, and TaSi2 and WSi2 particles were loaded on the fiber. Subsequently, SiC fiber was infiltrated by SiBCN ceramic precursors and then pyrolyzed to obtain gradient multilayer SiC/SiBCN ceramic fiber aerogel. The dense surface fiber reduced radiation heat transfer, and the porous structure of the aerogel decreased heat conduction and heat convection. The antioxidant particles improved the ceramic fiber aerogel's high-temperature oxidation resistance and thermal stability. The morphological structure, chemical composition, and thermal conductivity of ceramic fiber aerogel were characterized. The results showed that the gradient multilayer ceramic fiber aerogel had the comprehensive properties of ultra-low thermal conductivity, excellent infrared radiation shielding, and anti-oxidation performance. This study is expected to provide new ideas for constructing high-temperature thermal insulation ceramic aerogel.

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“…As a result, gradient multilayer SiC/SiBCN ceramic hybrid aerogel with excellent mechanical properties was successfully prepared. shown below [45,46]:…”

Section: Resultsmentioning

confidence: 99%

Gradient multi-layer ceramic fiber aerogel: Fabrication, anti-oxidation and thermal insulation

Zhong

Liu

et al. 2022

Preprint

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“…Transition metal silicides have the advantages of high hardness, high melting points, and low resistivities due to their covalent bonds and metal bonds, so they have received widespread attention in micro and nanoelectronics, aerospace systems, and thermoelectric materials [1][2][3]. MoSi 2 is a typical transition metal silicide that not only has the excellent electrical conductivity of metal and the high strength of ceramic, but also generates self-healing SiO 2 oxide films during the initial oxidation process [4][5][6] which gives MoSi 2 excellent oxidation resistance [7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Self-diffusion mechanisms based defect complexes in MoSi₂

Huang¹,

Fu²,

Xu³

et al. 2021

J. Phys.: Condens. Matter

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MoSi 2 is widely concerned due to excellent electrical conductivity, oxidation resistance as a typical transition metal silicide. The high-temperature diffusion behavior is one of the important factors for the degradation of MoSi 2 coatings. However, the diffusion mechanism in MoSi 2 is still unclear. Prior theoretical work mostly focused on defect formation energy, but these are not consistent with the self-diffusion experiments because the migration behaviors were not considered. Therefore, the purpose of this work was to investigate the microscopic diffusion mechanisms of Mo and Si atoms in MoSi 2 using density functional theory and the CI-NEB method. We confirmed that the temperature-dependent vibrational contribution has a significant impact on the defect formation free energy. The isolated point defects in MoSi 2 will tend to aggregate to form defect complexes, which participate in the atomic diffusion as mediators. The defect migration behaviors of atoms for vacancy mediated, vacancy complex mediated, and antisite assisted jumps were obtained based on electronic structures analysis. The results show that Si diffusion is mediated by intrasublattice jumps of the nearest neighbor Si vacancies. Moreover, the destroyed covalent Mo-Si bonds by Si vacancies and the non-directional weak metal bonds formed by the Mo antisites and Mo atoms could improve the mobility of the Mo atom which results in the low migration barrier. The agreement between our calculations and the reported experimental results indicates that the dominant diffusion mechanism for Mo atoms is mediated by vacancy complex mediated jumps and antisite assisted jumps. It is concluded that the Si vacancy-based defect complexes are likely the diffusion mediators for Mo atom self-diffusion in MoSi 2 . This work provides a deeper insight into the connection between the atomic mechanism and the macroscopic behavior for the diffusion in the MoSi 2 , and establishes the basis for further optimizing high-temperature coating materials.

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“…5 Molybdenum-based disilicides are regarded as the energy-storage materials because of their excellent electronic properties. 6 Tungsten disilicides show excellent thermoelectric properties, which are used in renewed thermoelectric or energy devices. 7 Among these TM disilicides, chromium-based disilicide (CrSi 2 ) attracted great attention as the ultrahigh-temperature ceramics and thermoelectric material because of its high strength, remarkable oxidation resistance, good electronic properties, and so forth.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Transition-metal (TM) disilicides are broadly applied for semiconductors, thermoelectric devices, high-temperature devices, and energy-storage systems. − Niobium-based disilicides are fascinating ultrahigh-temperature materials because they exhibit excellent high-temperature strength and good thermal stability . Molybdenum-based disilicides are regarded as the energy-storage materials because of their excellent electronic properties . Tungsten disilicides show excellent thermoelectric properties, which are used in renewed thermoelectric or energy devices …”

Section: Introductionmentioning

confidence: 99%

Structural Prediction and Overall Performances of CrSi₂ Disilicides: DFT Investigations

Pan

2020

ACS Sustainable Chem. Eng.

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Chromium-based silicides (Cr−Si) are broadly used in thermoelectric devices, semiconductors, ultrahigh-temperature devices, and energy-storage systems. However, the structural feature and related properties of CrSi 2 are not clear. Here, the structural, mechanical, and physical performances of CrSi 2 were studied from density functional theory investigations. Four phases: C40 (hexagonal)-CrSi 2 , C11 b (tetragonal)-CrSi 2 , C49 (orthorhombic)-CrSi 2 , and C54 (orthorhombic)-CrSi 2 are considered. In this work, two novel structures: C49 (orthorhombic)-CrSi 2 and C54 (orthorhombic)-CrSi 2 are first predicted. Especially, CrSi 2 with C11 b (tetragonal) has better stability compared to other CrSi 2 . Here, CrSi 2 with the C11 b (tetragonal) phase shows the strongest elastic modulus among all CrSi 2 . However, the Vickers hardness of CrSi 2 with the C49 (orthorhombic) phase is 34.9 GPa. Furthermore, the band gap of CrSi 2 with the C40 (hexagonal) phase and the C54 (orthorhombic) phase is 0.392 and 0.040 eV, respectively, indicating that they are semiconductor materials. Finally, the ultrahightemperature thermodynamic properties of CrSi 2 disilicides are determined from the lattice vibrations of Si and Si−Cr bonds.

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Effect of high temperature preoxidation treatment on the oxidation behavior of MoSi2- and WSi2–Al2O3 composites

Cited by 14 publications

References 65 publications

Gradient multi-layer ceramic fiber aerogel: Fabrication, anti-oxidation and thermal insulation

Gradient multi-layer ceramic fiber aerogel: Fabrication, anti-oxidation and thermal insulation

Self-diffusion mechanisms based defect complexes in MoSi₂

Structural Prediction and Overall Performances of CrSi₂ Disilicides: DFT Investigations

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Effect of high temperature preoxidation treatment on the oxidation behavior of MoSi2- and WSi2–Al2O3 composites

Cited by 14 publications

References 65 publications

Gradient multi-layer ceramic fiber aerogel: Fabrication, anti-oxidation and thermal insulation

Gradient multi-layer ceramic fiber aerogel: Fabrication, anti-oxidation and thermal insulation

Self-diffusion mechanisms based defect complexes in MoSi2

Structural Prediction and Overall Performances of CrSi2 Disilicides: DFT Investigations

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Product

Resources

About

Self-diffusion mechanisms based defect complexes in MoSi₂

Structural Prediction and Overall Performances of CrSi₂ Disilicides: DFT Investigations