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4741 |
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Tuesday, May 10, 2016, Auditorium 4:15 PM Young Professionals Session |
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Characterisation of thermally sprayed ZnAl15 corrosion protection coatings for offshore-wind-turbines |
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Martin Andreas Knoch* / RWTH Aachen University, Germany Kirsten Bobzin / Surface Engineering Institute, Germany Mehmet Öte/ Surface Engineering Institute, Germany Thomas Frederik Linke/ Surface Engineering Institute, Germany |
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Due to strong and steady winds in offshore environments, offshore-wind-turbines (OWT) offer a great potential for satisfying ever growing power demands and reducing the carbon footprint. However, corrosion is one of the main failure causes of OWT tower segments. Therefore, corrosion-protection-systems allowing for a maintenance-free protection of OWTs over their lifetime are crucial. Especially considering that repair costs are approximately 75 100 times higher than the cost of initial coating application. Thus this study aims at improving economic and environmental aspects related to OWTs by developing resource-efficient duplex-systems based on thermally sprayed ZnAl15 coatings. Based on the state of the art, duplex-coating-systems consisting of thermally sprayed ZnAl15, a sealer and several organic layers are investigated. Initially, minimal surface pre-treatment requirements were defined based on a specified adhesive strength (> 5 MPa). Furthermore, the feasibility of alloying Mg, Ti and Mn to the feedstock-material ZnAl15 is investigated. These new alloys are evaluated with regard to their corrosion-resistance using electro-chemical measurements. Additionally, the influence of using inert and active atomising-gases on process stability, morphology as well as corrosive resistance of the coatings is analysed. Using the results of a long-term-neutral-salt-spray-test, promising systems are selected for further investigations as part of a duplex-system. |