| 1. |
- Prosek, Tomas, et al.
(författare)
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Corrosion mechanism of model zinc-magnesium alloys in atmospheric conditions
- 2008
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Ingår i: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 50:8, s. 2216-2231
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Tidskriftsartikel (refereegranskat)abstract
- Recently, superior corrosion properties of zinc coatings alloyed with magnesium have been reported. Corrosion behaviour of model zinc-magnesium alloys was studied to understand better the protective mechanism of magnesium in zinc. Alloys containing from 1 to 32 wt.% magnesium, pure zinc, and pure magnesium were contaminated with sodium chloride and exposed to humid air for 28 days. Composition of corrosion products was analyzed using infrared spectroscopy (FTIR), ion chromatography (IC), and Auger electron spectroscopy (AES). The exposure tests were completed with scanning Kelvin probe (SKP) and electrochemical measurements. Weight loss of ZnMg alloys with 1-16 wt.% magnesium was lower than that of pure zinc. Up to 10-fold drop in weight loss was found for materials with 4-8 wt.% Mg in the structure. The improved corrosion stability of ZnMg alloys was connected to the presence of an Mg-based film adjacent to the metal surface. It ensured stable passivity in chloride environment and limited the efficiency of oxygen reduction.
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| 2. |
- Prosek, Tomas, et al.
(författare)
-
Corrosion properties of model zinc-magnesium alloys
- 2007
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Ingår i: GALVATECH 2007.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Recently, superior corrosion properties of novel zinc coatings alloyed with magnesium have been reported.The protection mechanism of magnesium in the coatings was studied on model zinc-magnesium alloys containing from1 to 32 wt. % Mg prepared by casting. Their chemical and phase composition was determined. The samples werecontaminated with NaCl and exposed to wet air. Weight loss was evaluated after 28 days of exposure. The compositionof corrosion products was analyzed using different techniques. The exposure tests were completed with scanning Kelvinprobe measurements. Alloying of zinc with small quantities of magnesium significantly decreased the weight lossof zinc-magnesium alloys. The effect was strongest at 4–8 wt. % Mg in the structure. Weight loss of these alloys was upto 10 times lower than that of zinc. This was found to be connected dominantly to the efficiency of the oxygenreduction, which was significantly limited on the surface of ZnMg phases covered with magnesium-based oxide layers.
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| 3. |
- Prosek, Tomas, et al.
(författare)
-
Effect of the microstructure of Zn-Al and Zn-Al-Mg model alloys on corrosion stability
- 2016
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Ingår i: Corrosion Science. - : Elsevier Ltd. - 0010-938X .- 1879-0496. ; 110, s. 71-81
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Tidskriftsartikel (refereegranskat)abstract
- Zn-5Al and Zn-3Al-2Mg model alloys were cast and heat treated in order to obtain specimens with distinct microstructures and identical chemical compositions. The microstructure was characterised in detail to identify composition, size and distribution of present phases. Mass losses of samples with different microstructures and identical chemical compositions that were subjected to a cyclic corrosion test and a test under non-rinsing conditions differed by a factor of up to two. The mechanism is discussed based on measurements of corrosion stability of individual phases and chemical and phase compositions of corrosion products.
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| 4. |
- Prosek, Tomas, et al.
(författare)
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Relationship between corrosion performance and microstructure of Zn-AI and Zn-AI-Mg model alloys
- 2015
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Ingår i: European Corrosion Congress, EUROCORR 2015. - : Austrian Society for Metallurgy and Materials (ASMET). - 9781510837379 ; , s. 511-522
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Konferensbidrag (refereegranskat)abstract
- Zn-5wt.%AI and Zn-3wt.%AI-2wt.%Mg model alloys were cast and heat treated in order to obtain specimens with distinct microstructure and identical chemical composition. The microstructure was characterized in detail using scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX) and x-ray diffraction spectroscopy (XRD) to identify chemical composition, size and distribution of present phases. Mass loss of samples with different microstructure and identical chemical composition subjected to a cyclic corrosion test and a test under non-rinsing conditions differed by a factor of up to two. Some model alloys showed better corrosion performance compared to commercial coatings with similar composition tested in parallel. This indicates that microstructure modification can improve the corrosion performance of industrial zinc alloy coatings. The mechanism is discussed based on measurements of corrosion stability of individual phases, preferential corrosion, composition and stability of corrosion products, dc electrochemical characteristics and infrared absorption spectroscopy (IRRAS) experiments.
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