14 research outputs found

    Redox reactions and structure - properties relations in mixed alkali/alkaline earth glasses : The role of antimony oxides during the fining process- A structural study of copper(I) and copper(II)

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    It is important to optimize glass compositions for their specific purpose but also for the efficiency of the production process, the manufacturing of glass. This will be beneficial economically and environmentally. Today many processes and glass compositions are already optimized, but due to more strict legislation on toxic elements and substances there must be changes in many glass compositions. One of these elements is antimony; the oxide is used as fining agent to obtain a bubble free glass within a reasonable process time. One aim with this thesis is to obtain a deeper understanding of the fining mechanism in 20R2O-10MO-70SiO2 (R=Na and/or K, M = Ca and/or Ba, Mg, Sr) glasses in order to minimise the amount of Sb2O3. Another intention is to study the structure of 20R2O-10CaO-70SiO2 (R = Na, K) with Cu2+ as probe ion and thus get a deeper knowledge of the surrounding glass matrix.  The optical basicity scale is used to determine the acid/base character of the different glass compositions.   Fining efficiency results showed a remarkable increase of the number of remaining bubbles when the glass contains either approximately equal amounts of Na and K or Ca and Ba, Mg or Sr. The much higher number of bubbles in the potassium containing glasses compared to the sodium containing is explained by the increase in viscosity, the increase in optical basicity and thus lower oxygen activity. The differences in the fining efficiency when altering alkaline earth ions cannot be explained by the optical basicity values, it seems to be a more complicated situation.   This thesis also reports maximum in Vickers hardness and packing density as well as minimum in glass transition temperature for the mixed alkali glasses. The mixed alkaline earth glasses do not exhibit any clear nonlinear behaviour. Raman spectroscopy measurements showed a variation in the network connectivity which has a clear relation to the optical basicity of the different glass compositions. The combination of UV-Vis-NIR and X-ray absorption spectroscopy measurements showed that the coordination sphere for Cu(II) is a tetragonal distorted octahedron with two elongated Cu-O bonds along the z axis. There were no trends in the degree of tetragonal distortion, thus it was about the same for all the investigated glass compositions. Cu(I) is found to be coordinated by two oxygen ligands in mainly linear coordination sphere, evidenced from X-ray absorption spectroscopy

    ETERNAL GLASS. Rapport - studie om Ă„tervinning av glas

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    I vilken omfattning kan ökad Ätervinning av glas leda till minskad energianvÀndningoch minskade koldioxidutslÀpp vid glasproduktion, minskad miljöpÄverkan genomdeponi samt pÄ lÄng sikt möjligen minskad brytning av icke-förnyelsebar naturrÄvara?Studien Àr finansierad av Glasforskningsföreningen Glafo</p

    Transition metal valence in commercial glasses analysed using X-ray Absorption Spectroscopy at Balder beamline, MAX IV

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    The stone wool manufacturer Paroc (a part of Owens Corning) considers blending in additional waste materials into the production to obtain a more sustainable product. By using waste material that otherwise would go to the landfill also less virgin raw material (volcanic rock) would be used. The waste material contains manganese (Mn) which may potentially affect the iron (Fe) redox equilibria that greatly affects the melt and product properties. Paroc therefor wish to understand and simulate the effect of blending in additional waste material in their product.Transition metal valence in commercial glasse

    Simultaneous chemical vapor deposition and thermal strengthening of glass

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    In the current paper we present a concept combining metal organic chemical vapor deposition with thermal strengthening process of flat glass. As the flat glass is heated to be thermally strengthened, which takes up to 20 minutes, there is an opportunity for performing a surface modification. We describe the application of transparent and amorphous Al2O3 thin films during the thermal strengthening process. Al2O3 was chosen due to the following desirable properties: increased surface mechanical properties and increased chemical durability, the latter has not been investigated in the current paper. The residual surface compressive stresses after performed strengthening of the coated glasses were quantified to be in the range of 80–110 MPa. The Al2O3 content in the surface was measured using the Surface Ablation Cell employed with Inductively Coupled Plasma Atomic Emission Spectroscopy and found to be at least doubled at the surface and having an increased Al2O3 content at least 0.5â€ŻÎŒm underneath the glass surface. During the surface reaction, sodium is migrating to the surface giving a hazy salt layer on the glass which can easily be washed off with water. The applied coatings are transparent and provide increased surface hardness and crack resistance at low indentation loads. At higher indentation loads the interaction volume is larger and displays the same effect on the surface mechanical properties as for thermally strengthened glass. The contact angle with water compared to annealed float glass is significantly increased from 5° to 45° due to the different surface chemistry and surface topography

    Förstudie - Ny glasgÄng för Kulturparken SmÄland : Hur kan transparent intelligens utnyttjas i en offentlig miljö?

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    Tankarna pÄ att bygga en glasgÄng mellan SmÄlands museum och Utvandrarnas hus har funnits ett tag. NÀr det kommunala fastighetsbolaget Vöfab köpte museibyggnaden av Stiftelsen SmÄlands museum i december 2014 och all mark mellan byggnaderna sÄ var ett avgörande juridiskt hinder undanröjt. Nu fanns det möjlilghet att bygga en glasgÄng. Förstudiens mÄl Àr att synliggöra och tvÀrvetenskapligt undersöka möjligheterna att anvÀnda transparent intelligens vid gestaltning av en ny glasgÄng som ett tilltalande inslag i VÀxjös offentliga miljö. I rapporten beskrivs transparent intelligens och ger mÄnga exempel inklusive figurer, bÄde pÄ tekniker och ocksÄ byggnader. I rapporten berÀttas ocksÄ omkonstnÀrlig gestaltning och utmanande arkitektur, materialet glas beskrivs bÄde ingenjörsmÀssigt och designmÀssigt. Förstudien visar vilka möjligheter det finns att anvÀnda transparent intelligens nÀr en offentlig byggnad ska byggas, men ocksÄ vilka begrÀnsningar (t.ex. ljud, ljus, vÀrme, kyla, underhÄllsvÀnlighet, teknik). En litteratursökning har visat att det finns byggnader som fungerar som en dekoration samtidigt som det har en funktion, i en offentlig miljö. I och med att det hÀnder mycket inom omrÄdet intelligent transparens sÄ byggs det nya prototyper med den senaste tekniken eller en gammal teknik som anvÀnds pÄ ett nytt sÀtt. Inom Smart Housing SmÄland görs det nya prototyper i samarbete med industrin, som kan visas upp i glasgÄngen, om den blir verklighet. Detta gör att allmÀnheten fÄr ta del av den senaste tekniken inom intelligent transparens

    Non-destructive testing of the glass strength in flat glass with indentationinduced cracks by Nonlinear Acoustic Wave method

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    Glass is a unique but unfortunately brittle material whose strength is primarily limited by the presenceof cracks on the surface [1]. The strength of glass is limited by the fact that very high stresses arise atthe crack tips when subjected to tensile load. In principle, without the presence of surface cracks, glasswould have a strength far exceeding many other structural materials, e.g., steel. The size and thedistribution of surface cracks vary greatly, which results in the strength of glass exhibit a great variationand thus requires that large safety margins must be applied for glass in practical applications, e.g., whenused as a load bearing building material.Today, there are no methods to determine the strength of flat glass non-destructively. Instead, thestrength is determined by different experimental methods requiring &gt;10 samples for sufficient statistics.This procedure requires both lots of glassy materials and time. The future aim is to investigate if the useof nonlinear acoustic waves (NAW) could be an alternative for developing a standardized designstrength value. Developing a non-destructive inspection method for determining the glass strength is ascientific breakthrough that will have a great industrial impact for the sustainable development of glassmanufacturing.With the use of NAW it is possible to detect and quantify the defects in materials [2,3]. The nonlinearwaves are transmitted through the object and the nonlinear effects, caused by the defects in thematerial, corresponds to the level of damage in the material. This work present result from samplescontaining relatively precise defects. The defects were created using a microindenter with a sufficientload to cause indentation induced cracking in the glass. The indentations were created using a Vickersdiamond tip in the middle of commercial 4 mm float glass samples of the dimensions 10x10 cm2. Theapplied loads were 0.5N, 1N, 2N, 5N and 10N. The “damage value” of the sample series was thenquantified using the NAW technique. The fracture strength of the samples was correlated destructivelyusing a conventional ring-on-ring setup.The results show that there is a clear correlation between the indenter load, the damage value from theNAW inspection and the fracture strength. We noted that the standard deviation for the ring-on-ringtests for the 1N, 2N, 5N and 10N was low while the 0.5N and the reference samples presented a highstandard deviation. A possible explanation for this observation is that for 0.5N not all indents give radialcracks but in some cases the indentation produces only plastic deformation. The main conclusion fromthe research is that is possible to detect realistically large defects in glass using the non-destructive NAWmethod and these defects cannot be seen with the naked eye. Moreover, the results can be directlycorrelated with the strength of glass [4]. References[1] Veer, F.A. and Y.M. Rodichev, The structural strength of glass: hidden damage. Strength of Materials, 2011.43(3): p. 302-315. DOI: 10.1007/s11223-011-9298-5.[2] Persson, K., K. Haller, S. Karlsson, and M. KozƂowski, Non-destructive testing of the strength of glass by a nonlinearultrasonic method. Challenging Glass Conference Proceedings, 2020. 7. DOI: 10.7480/cgc.7.4498.[3] Haller, K., Doctoral Thesis: Acoustical measurements of material nonlinearity and nonequilibrium recovery.2008: Department of Mechanical Engineering, Blekinge Institute of Technology.[4] Karlsson, S., L. Grund BĂ€ck, S. Andersson, K. Haller, M. KozƂowski, and K. Persson, Strength classification of flatglass for better quality – validation of method by well-defined surface defects and strength testing, in ÅForskReport,19-479. 2021: http://dx.doi.org/10.13140/RG.2.2.32992.40962.Tunnare och starkare glas för hĂ„llbar produktion och konsumtio

    Non‐destructive assessment of the glassstrength using nonlinear acoustics

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    Tunnare och starkare glas för hÄllbar produktion och konsumtio

    Non-destructive testing of the glass strength in flat glass with indentationinduced cracks by Nonlinear Acoustic Wave method

    No full text
    Glass is a unique but unfortunately brittle material whose strength is primarily limited by the presenceof cracks on the surface [1]. The strength of glass is limited by the fact that very high stresses arise atthe crack tips when subjected to tensile load. In principle, without the presence of surface cracks, glasswould have a strength far exceeding many other structural materials, e.g., steel. The size and thedistribution of surface cracks vary greatly, which results in the strength of glass exhibit a great variationand thus requires that large safety margins must be applied for glass in practical applications, e.g., whenused as a load bearing building material.Today, there are no methods to determine the strength of flat glass non-destructively. Instead, thestrength is determined by different experimental methods requiring &gt;10 samples for sufficient statistics.This procedure requires both lots of glassy materials and time. The future aim is to investigate if the useof nonlinear acoustic waves (NAW) could be an alternative for developing a standardized designstrength value. Developing a non-destructive inspection method for determining the glass strength is ascientific breakthrough that will have a great industrial impact for the sustainable development of glassmanufacturing.With the use of NAW it is possible to detect and quantify the defects in materials [2,3]. The nonlinearwaves are transmitted through the object and the nonlinear effects, caused by the defects in thematerial, corresponds to the level of damage in the material. This work present result from samplescontaining relatively precise defects. The defects were created using a microindenter with a sufficientload to cause indentation induced cracking in the glass. The indentations were created using a Vickersdiamond tip in the middle of commercial 4 mm float glass samples of the dimensions 10x10 cm2. Theapplied loads were 0.5N, 1N, 2N, 5N and 10N. The “damage value” of the sample series was thenquantified using the NAW technique. The fracture strength of the samples was correlated destructivelyusing a conventional ring-on-ring setup.The results show that there is a clear correlation between the indenter load, the damage value from theNAW inspection and the fracture strength. We noted that the standard deviation for the ring-on-ringtests for the 1N, 2N, 5N and 10N was low while the 0.5N and the reference samples presented a highstandard deviation. A possible explanation for this observation is that for 0.5N not all indents give radialcracks but in some cases the indentation produces only plastic deformation. The main conclusion fromthe research is that is possible to detect realistically large defects in glass using the non-destructive NAWmethod and these defects cannot be seen with the naked eye. Moreover, the results can be directlycorrelated with the strength of glass [4]. References[1] Veer, F.A. and Y.M. Rodichev, The structural strength of glass: hidden damage. Strength of Materials, 2011.43(3): p. 302-315. DOI: 10.1007/s11223-011-9298-5.[2] Persson, K., K. Haller, S. Karlsson, and M. KozƂowski, Non-destructive testing of the strength of glass by a nonlinearultrasonic method. Challenging Glass Conference Proceedings, 2020. 7. DOI: 10.7480/cgc.7.4498.[3] Haller, K., Doctoral Thesis: Acoustical measurements of material nonlinearity and nonequilibrium recovery.2008: Department of Mechanical Engineering, Blekinge Institute of Technology.[4] Karlsson, S., L. Grund BĂ€ck, S. Andersson, K. Haller, M. KozƂowski, and K. Persson, Strength classification of flatglass for better quality – validation of method by well-defined surface defects and strength testing, in ÅForskReport,19-479. 2021: http://dx.doi.org/10.13140/RG.2.2.32992.40962.Tunnare och starkare glas för hĂ„llbar produktion och konsumtio
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