Viscosity of many-component glasses

Hrma, Pavel R.; Arrigoni, Benjamin M.; Schweiger, Michael J.

doi:10.1016/j.jnoncrysol.2009.03.005

Cited by 37 publications

(36 citation statements)

References 14 publications

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“…As has been demonstrated with various viscosity databases, both for commercial 4,5 and waste glasses, 5,6 high-temperature viscosity is best fitted by an Arrhenius function,…”

Section: 3mentioning

confidence: 61%

“…The most popular among them are the Vogel-Fulcher-Tammann equation and the Adam-Gibbs equation, 1 the latter of which is more versatile and allows better fitting of high-temperature data. 2,3 As has been demonstrated with various viscosity databases, both for commercial 4,5 and waste glasses, 5,6 high-temperature viscosity is best fitted by an Arrhenius function,…”

Section: Viscosity-composition Relationshipsmentioning

confidence: 83%

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Effect of glass composition on activation energy of viscosity in glass-melting-temperature range

Hrma

Han

2012

Journal of Non-Crystalline Solids

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Viscosity, a key property for glass processing, is a function of glass composition and temperature. Nuclear waste glasses must be formulated to obtain a desired viscosity at the melter processing temperature for each waste composition to be vitrified. Over the past decades, a large viscosity database has been accumulated at various laboratories in the US. The database, compiled at the Pacific Northwest National Laboratory, comprises over 1300 compositions with 83 components and 6800 viscosity data. We used this database to develop a mathematical model for the viscosity-composition relationship for viscosities lower than 1000 Pa·s that are important for the melting process. In this high-temperature range, the viscosity-temperature relationship has the form of an Arrhenius function, i.e., ln(η) = A + B/T, where η is the viscosity, T is the absolute temperature, A is a constant coefficient, and B is the activation energy. We obtained B for each data point and then fitted a first-or second-order model to B as a function of glass composition while A was kept constant for all glasses. Altogether, we have developed 12 versions of viscosity-composition relationships with a variety of first-and second-order coefficients. Two models, one first order and one second order, are presented in this paper. I. VISCOSITY-COMPOSITION RELATIONSHIPSViscosity-temperature relationships are important for both glass melting and glass forming. Over the wide interval of temperatures-from the glass transition temperature to the temperature at which glass is being refined-viscosity spans 12 orders of magnitude. Many approximation functions have been suggested in the literature to model the viscosity-temperature relationship. The most popular among them are the Vogel-Fulcher-Tammann equation and the Adam-Gibbs equation, 1 the latter of which is more versatile and allows better fitting of high-temperature data. 2,3As has been demonstrated with various viscosity databases, both for commercial 4,5 and waste glasses, 5,6 high-temperature viscosity is best fitted by an Arrhenius function,where η is the viscosity, T is the temperature, A is a constant coefficient, and B is the activation energy. In Equation (1), both A and B are independent of temperature. Thus, for low viscosities, η < 10 3 Pa·s, the activation energy depends on composition only. Because the melting temperatures of glass are usually below 10 Pa·s, Equation (1) fully suffices for formulating glasses to meet melt-processing constrains with respect to glass formulation as well as mathematical modeling of glass-melting furnaces.

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“…As has been demonstrated with various viscosity databases, both for commercial 4,5 and waste glasses, 5,6 high-temperature viscosity is best fitted by an Arrhenius function,…”

Section: 3mentioning

confidence: 61%

Section: Viscosity-composition Relationshipsmentioning

confidence: 83%

Effect of glass composition on activation energy of viscosity in glass-melting-temperature range

Hrma

Han

2012

Journal of Non-Crystalline Solids

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“…It is affected by temperature and the fraction of silica dissolved. For the A0 glass (with all components dissolved), η = exp (A + B/T) with A = −12.511 (for η in Pa s) and B = 1.9981 × 10 4 K. The activation energy (B) being a linear function of composition [22], we can write B = B S x S + (1 -x S )B R , where B S = 2.894 × 10 4 K is the component coefficient for SiO 2 [22], x S is the mass fraction SiO 2 , and B R is the component coefficient for all remaining components (if all remaining components are present in the glass-forming melt, their proportions are constant, and thus can be treated as one component). Since in the final glass x S = 0.3050, we obtain B R = 16049 K. Fig.…”

Section: Discussionmentioning

confidence: 99%

Cluster formation of silica particles in glass batches during melting

Schweiger

Hrma

Humrickhouse

et al. 2010

Journal of Non-Crystalline Solids

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“…11,15) ZrO 2 has been found to be an acidic oxide according to Hrma et al 16) and the alkali oxide Na 2 O is well known to behave as a strong basic oxide, 17,18) but these constituents are fixed within the flux system and has not been considered within the extended basicity. Al 2 O 3 , which is known to be an amphoteric oxide, can generally be considered to behave as a network forming oxide in the absence of significant acidic components such as SiO 2 similar to the present TiO 2 -MnO-Al 2 O 3 -8.64ZrO 2 -2.77Na 2 O flux system.…”

Section: Melt Structure Analysis Using Raman and Xpsmentioning

confidence: 99%

Effect of Alumina and Extended Basicity on the Viscosity and Structure in the TiO2-MnO-Al2O3-8.64ZrO2-2.77Na2O Welding Flux System

Kim

Sohn

2014

ISIJ Int.

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The high temperature viscosity of the TiO2-MnO-Al2O3-8.64ZrO2-2.77Na2O welding flux system was measured by the rotating spindle method to identify the relationship between the viscosity and melt structure at various compositions of TiO2, MnO, and Al2O3 contents. At temperatures of 1 773 K to 1 748 K and fixed TiO2/MnO ratio, the effect of Al2O3 on the viscosity was not significant, but slightly increased with higher Al2O3. At temperatures below 1 748 K, the effect of Al2O3 was more pronounced with increments of Al2O3 significantly increasing the viscosity of the molten flux. Increased extended basicity ((TiO2/+1.13MnO)/SiO2) depolymerized the network structure, where TiO2 and MnO works to depolymerize the present melt. Raman analysis of as-quenched oxide melts from 1 773 K showed the symmetric [AlO4]-tetrahedral stretching vibrations to increase and the asymmetric [AlO6]-octahedral stretching vibrations to decrease with higher concentration of Al2O3 at various fixed TiO2/MnO ratios suggesting polymerization of the structure with Al2O3 additions. The opposite trend could be observed with increasing extended basicity. XPS (xray photoelectron spectroscopy) results showed the bridged oxygen (O o ) to increase and the non-bridged oxygen (O -) to decrease with Al2O3 additions and lower extended basicity also suggesting polymerization of the network structure in the present melt system.

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Viscosity of many-component glasses

Cited by 37 publications

References 14 publications

Effect of glass composition on activation energy of viscosity in glass-melting-temperature range

Effect of glass composition on activation energy of viscosity in glass-melting-temperature range

Cluster formation of silica particles in glass batches during melting

Effect of Alumina and Extended Basicity on the Viscosity and Structure in the TiO2-MnO-Al2O3-8.64ZrO2-2.77Na2O Welding Flux System

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