| 1. |
- Chang, Tingru, et al.
(författare)
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The role of Sn on the long-term atmospheric corrosion of binary Cu-Sn bronze alloys in architecture
- 2019
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Ingår i: Corrosion Science. - : Elsevier Ltd. - 0010-938X .- 1879-0496. ; 149, s. 54-67
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Tidskriftsartikel (refereegranskat)abstract
- The role of Sn on the atmospheric corrosion performance of binary Cu-Sn bronze alloys (4–6 wt.% Sn) compared with Cu metal used in outdoor architecture is elucidated in terms of microstructure, native surface oxide composition, patina evolution, corrosion rates, appearance and metal release. Results are presented for non-exposed surfaces and surfaces exposed at different urban and marine sites in Europe up to 5 years and based on multi-analytical findings from microscopic, spectroscopic, electrochemical and chemical investigations. Alloying influenced the corrosion, aesthetic appearance and patina evolution, differently for urban and marine sites, whereas no effects were observed on the release pattern. © 2019 The Authors
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| 2. |
- Goidanich, S., et al.
(författare)
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Atmospheric corrosion of brass in outdoor applications Patina evolution, metal release and aesthetic appearance at urban exposure conditions
- 2011
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 412, s. 46-57
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Tidskriftsartikel (refereegranskat)abstract
- Short (days, weeks) and long-term (months, years) non-sheltered field exposures of brass (15, and 20 wt.% Zn) and copper sheet have been conducted in three European cities (Milan, Stockholm, Madrid) to generate an in-depth time-dependent understanding of patina evolution, corrosion rates, aesthetic appearance, metal release and degree of dezincification in relation to detailed bulk and surface characteristics prior to exposure. This has been accomplished by using a multitude of surface and bulk analytical tools, chemical analysis and colorimetric investigations. Small differences in surface finish and local variations in nobility observed for the non-exposed brass alloys resulted in slight differences in corrosion initiation. Despite different kinetic behaviour and relative surface distributions of zinc- and copper-rich patina constituents, similar phases were identified with copper-rich phases rapidly dominating the outermost patina layer in Milan, compared to Madrid and Stockholm showing both copper- and zinc-rich phases. As a consequence of differences in surface coverage of copper- and zinc-rich corrosion products at the different sites, the release ratios of copper to zinc varied concordantly. The released amount of zinc to copper (Zn/Cu) was for both alloys and test sites always higher compared to the bulk composition showing a preferential release of zinc. The amount of released copper from the brass alloys was on an average 30-40% lower compared to copper sheet at all test sites investigated. Significantly lower annual total release rates of copper and zinc compared with annual corrosion rates were evident for both brass alloys at all sites.
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| 3. |
- Goidanich, S., et al.
(författare)
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Effect of the environment on the metal release and corrosion behaviour of different copper-based alloys : Field exposures at 5 different test sites in Europe
- 2008
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Ingår i: 17th International Corrosion Congress 2008. - 9781615674251 ; , s. 102-115
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Konferensbidrag (refereegranskat)abstract
- Diffuse emissions and dispersion of metals from different sources in the society have lately received an increased concern from an environmental perspective. Large research efforts have been initiated and undertaken by the division of Corrosion Science at KTH to fill knowledge gaps on corrosion-induced metal release from external constructions and buildings. The generation of such data is of paramount importance for the on-going assessment of flows and potential adverse environmental effects caused by released metals. Generated information is also essential for an improved understanding of prevailing atmospheric corrosion processes of importance for the preservation of our cultural heritage, e.g. bronze statues exposed to the atmosphere. This paper summarizes and compares long-term metal release data from pure copper, bronze (6%wt Sn) and brass (20%wt Zn) exposed at unsheltered conditions in five European environments of significantly different climatic and pollutant conditions; three urban sites (Stockholm-Sweden, Milan-Italy and Madrid-Spain) and two marine sites (Brest-France, Cadiz-Spain). Generated data are interpreted with respect to parallel multi-analytical studies of changes in patina characteristics, corrosion rates and differences in prevailing environmental conditions.
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| 4. |
- Hedberg, Yolanda S., et al.
(författare)
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Critical Review : Copper Runoff from Outdoor Copper Surfaces at Atmospheric Conditions
- 2014
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 48:3, s. 1372-1381
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Forskningsöversikt (refereegranskat)abstract
- This review on copper runoff dispersed from unsheltered naturally patinated copper used for roofing and facades summarizes and discusses influencing factors, available literature, and predictive models, and the importance of fate and speciation for environmental risk assessment. Copper runoff from. outdoor surfaces is predominantly governed by electrochemical and chemical reactions and is highly dependent on given exposure conditions (size, inclination, geometry, degree of sheltering, and orientation), surface parameters (age, patina composition, and thickness), and site-specific environmental conditions (gaseous pollutants, chloride, rainfall characteristics (amount, intensity, pH), wind direction, temperature, time of wetness, season). The corrosion rate cannot be used to assess the runoff rate. The extent of released copper varies largely between different rain events and is related to dry and wet periods, dry deposition prior to the rain event and prevailing rain and patina characteristics. Interpretation and use of copper runoff data for environmental risk assessment and management need therefore to consider site-specific factors and focus on average data of long-term studies (several years). Risk assessments require furthermore that changes in copper speciation, bioavailability aspects, and potential irreversible retention on solid surfaces are considered, factors that determine the environmental fate of copper runoff from outdoor surfaces.
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| 5. |
- Hedberg, Yolanda S., et al.
(författare)
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Surface rain interactions : Differences in copper runoff for copper sheet of different inclination, orientation, and atmospheric exposure conditions
- 2015
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424. ; 196, s. 363-370
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Tidskriftsartikel (refereegranskat)abstract
- Predictions of the diffuse dispersion of metals from outdoor constructions such as roofs and facades are necessary for environmental risk assessment and management. An existing predictive model has been compared with measured data of copper runoff from copper sheets exposed at four different inclinations facing four orientations at two different urban sites (Stockholm, Sweden, and Milan, Italy) during a 4-year period. Its applicability has also been investigated for copper sheet exposed at two marine sites (Cadiz, Spain, for 5 years, and Brest, France, for 9 years). Generally the model can be used for all given conditions. However, vertical surfaces should be considered as surfaces inclined 60-80 degrees due to wind-driven effects. The most important parameters that influence copper runoff, and not already included in the model, are the wind and rain characteristics that influence the actual rainfall volume impinging the surface of interest. (C) 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).
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