Effect of Zr doping on the high-temperature stability of SiO2 glass

Cheng, Chunyu; Li, Hejun; Fu, Qiangang; Guo, Liping; Sun, Jia; Yin, Xiaowei

doi:10.1016/j.commatsci.2018.01.051

Cited by 34 publications

(9 citation statements)

References 19 publications

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“…To further understand the effect of Me atom on the c‐SiO 2 , Me atom was doped into c‐SiO 2 . Since naturally 4‐valent oxides TiO 2 , ZrO 2 , and HfO 2 similar to SiO 2 , the Ti, Zr, and Hf atoms are considered to substitute the host Si atom, 14 as shown in Figure 6A. After geometry optimization, the solution energies of the c‐SiO 2 doped with Ti, Zr, and Hf are −7.74, −8.05, 14 and −10.41 eV, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…Since naturally 4‐valent oxides TiO 2 , ZrO 2 , and HfO 2 similar to SiO 2 , the Ti, Zr, and Hf atoms are considered to substitute the host Si atom, 14 as shown in Figure 6A. After geometry optimization, the solution energies of the c‐SiO 2 doped with Ti, Zr, and Hf are −7.74, −8.05, 14 and −10.41 eV, respectively. The negative solution energies indicate that the doped c‐SiO 2 structures are stable.…”

Section: Resultsmentioning

confidence: 99%

“…Wang et al 12,13 reported that the addition of W and Nb improved the oxidation resistance of SiC coating by enhancing the stability of the protective liquid/glassy SiO 2 scale. Our previous experiment work 14 showed that the addition of Zr increased the high‐temperature stability of SiO 2 glass, which was explained by first‐principle calculation. However, the data about the effect of series of transition metal additives on the high‐temperature characteristic of SiO 2 glass at 1700°C in different works are not directly comparable due to various compositions, oxidation conditions, and sample size.…”

Section: Introductionmentioning

confidence: 85%

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Evaporation behavior of SiO₂ glass doped with various transition metal oxides

Cheng

Xie

et al. 2021

J. Am. Ceram. Soc.

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To investigate the effect of transition metal oxides on the evaporation characteristic of SiO 2 glass at 1700°C, nine transition metal oxides were added to SiO 2 glass. The results show that V 2 O 5 , MoO 3 , and WO 3 have little effect on the high-temperature stability of SiO 2 glass due to their evaporation at 1500-1700°C. Besides, Nb 2 O 5 and Ta 2 O 5 reduce the evaporation of SiO 2 by covering the surface of the sample. Moreover, by improving the content of cristobalite, the evaporation of the SiO 2 -Cr 2 O 3 sample decreases. Meanwhile, TiO 2 , ZrO 2 , and HfO 2 are beneficial to decreasing the evaporation of SiO 2 glass because Ti, Zr, and Hf diffuse into c-SiO 2 . Meanwhile, the SiO 2 -HfO 2 sample possesses the least evaporation.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 85%

See 1 more Smart Citation

Evaporation behavior of SiO₂ glass doped with various transition metal oxides

Cheng

Xie

et al. 2021

J. Am. Ceram. Soc.

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“…In turn, an increase in viscosity decreases the rate of oxygen diffusion through the oxide film according to the Stokes-Einstein relation. Another potential advantage of increased viscosity along with an increased liquidus temperature is a slight decrease in the vapor pressure of heterogeneous borosilicate films as compared to homogeneous borosilicate glass [35,36]. However, it should be taken into account that the catalytic activity of heterogeneous silicate systems will be higher than that of similar homogeneous ones [13,37].…”

Section: Selection Of the Experimental Coating Compositionmentioning

confidence: 99%

“…(а) (b) It is known [9,13,36] that with an increase in the operating temperatures of boride-silicide coatings, including those containing Si and/or SiC, above Tw = 1730-1750 °C, a sharp intensification of the processes of sublimation of the borosilicate glass phase occurs as a result of the formation of volatile oxides SiO and BOx, the vapor pressure of which increases with increasing temperature and decreasing external pressure. This, in turn, leads to disruption of the continuity of the oxide film and to additional heating as a result of an increase in catalyticity with respect to the reactions of heterogeneous recombination of atoms and ions of the air plasma at active centers of the surface.…”

Section: Coating Behavior Under Conditions Of Heating By a High-speed Air Plasma Flowmentioning

confidence: 99%

Oxidation Resistance of a Si–TiSi2–MoSi2–TiB2–CaSi2 Coating on a Cf/C–SiC Substrate in High-Speed High-Enthalpy Air Plasma Flows

2021

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The results of a study on the development and testing of a heat-resistant coating in a Si–TiSi2–MoSi2–TiB2–CaSi2 system to protect Cf/C–SiC composites from oxidation and erosional entrainment in high-speed flows are presented here. The coating was formed using firing fusion technology on the powder composition. Oxidation resistance tests were carried out under static conditions in air at 1650 °C and under conditions of interaction with high-speed air plasma flows, with Mach numbers M = 5.5–6.0 and enthalpy 40–50 MJ/kg. The effectiveness of the protective action of the coating was confirmed at surface temperatures of Tw = 1810–1820 °C for at least 920–930 s, at Tw = 1850–1860 °C for not less than 510–520 s, at Tw = 1900–1920 °C for not less than 280–290 s, and at Tw = 1940–1960 °C for not less than 100–110 s. The values of the rate of loss of the coating mass and the rate constant of heterogeneous recombination of atoms and ions of air plasma on its surface were estimated. The performance of the coating was ensured by the structural-phase state of its main layer, and the formation and evolution on its surface during operation of a passivating heterogeneous oxide film. This film, in turn, is composed of borosilicate glass with titanium and calcium liquation inhomogeneities, reinforcing TiO2 microneedles and in situ Si2ON2 fibers. It was shown that at Tw≥ 1850–1860 °C, the generation of volatile silicon monoxide was observed at the “oxide layer–coating” interface, followed by the effects of boiling and breakdown degradation of the oxide film, which significantly reduced the lifespan of the protective action of the coating.

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Improved Thermal Stability and Oxygen‐Barrier Performance of SiO₂ Thin Films by Modifying Amorphous Network Structure

Xiong,

Yang,

Chen

et al. 2024

Physica Rapid Research Ltrs

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Due to low refractive‐index and grain‐boundary‐free features, amorphous SiO2 thin films possess inherent advantages in serving as antireflective and protective layers against atmosphere. However, under high‐temperature or/and oxidation harsh environment, the thermodynamic instability of Si‐O bonds and ‘depolymerization’ process among tetrahedral units [SiO4] would result in their insufficient thermal stability and oxygen‐barrier failure. By taking amorphous network former, small element electronegativity and high oxide dissociation energy into considerations, we introduce low‐level Zr dopant to induce short‐ and medium‐range structural modification in amorphous SiO2 thin films, aiming to shorten Si‐O bond length and enhance network connectivity, respectively. As expected, the fabricated SiZrO thin films exhibit superior thermal stability and oxygen‐barrier performance without sacrificing their low‐index attribute. The Zr doping significantly elevates the oxygen‐inward‐diffusion activation energy from 0.94 eV to 1.95 eV in SiO2 network. Further, utilizing as protective layer for W‐SiO2 cermet, the SiZrO can effectively prevent the oxidation of W nanoparticles caused by oxygen inward diffusion. Undoubtedly, the exploration of amorphous SiZrO thin films offers exciting prospects for the application of functional coatings and devices under extreme conditions.This article is protected by copyright. All rights reserved.

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Effect of Zr doping on the high-temperature stability of SiO2 glass

Cited by 34 publications

References 19 publications

Evaporation behavior of SiO₂ glass doped with various transition metal oxides

Evaporation behavior of SiO₂ glass doped with various transition metal oxides

Oxidation Resistance of a Si–TiSi2–MoSi2–TiB2–CaSi2 Coating on a Cf/C–SiC Substrate in High-Speed High-Enthalpy Air Plasma Flows

Improved Thermal Stability and Oxygen‐Barrier Performance of SiO₂ Thin Films by Modifying Amorphous Network Structure

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Effect of Zr doping on the high-temperature stability of SiO2 glass

Cited by 34 publications

References 19 publications

Evaporation behavior of SiO2 glass doped with various transition metal oxides

Evaporation behavior of SiO2 glass doped with various transition metal oxides

Oxidation Resistance of a Si–TiSi2–MoSi2–TiB2–CaSi2 Coating on a Cf/C–SiC Substrate in High-Speed High-Enthalpy Air Plasma Flows

Improved Thermal Stability and Oxygen‐Barrier Performance of SiO2 Thin Films by Modifying Amorphous Network Structure

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Product

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Evaporation behavior of SiO₂ glass doped with various transition metal oxides

Evaporation behavior of SiO₂ glass doped with various transition metal oxides

Improved Thermal Stability and Oxygen‐Barrier Performance of SiO₂ Thin Films by Modifying Amorphous Network Structure