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| Abstract No.: |
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Scheduled at:
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Thursday, September 29, 2011, Saal A 11:05 AM
Young Professionals
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| Title: |
Thermal spraying of advanced zinc alloys as an addition to hot-dip galvanizing
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| Authors: |
Christiane Schulz* / Surface Engineering Institute, RWTH Aachen University, Germany
Kirsten Bobzin / Surface Engineering Institute, RWTH Aachen University, Germany
Thomas Schläfer/ Surface Engineering Institute, RWTH Aachen University, Germany
Thomas Warda/ Surface Engineering Institute, RWTH Aachen University, Germany
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| Abstract: |
Hot-dip galvanizing is usually used to protect steel structures from corrosion in aggressive conditions. However, limitations regarding component size and composition of the galvanizing bath exist. In recent years wire arc spraying of zinc and its alloys has been widely adopted as a coating process for parts that cannot be hot-dip galvanized or where zinc alone does not provide sufficient corrosion protection. Therefore advanced zinc alloys have been developed which show promising results in the matter of corrosion protection. In order to enhance the performance of thermally sprayed Zn-coatings, alloying elements such as Al, Mg, Cr and Sn were used to produce solid as well as cored wires. Coatings have been tested in salt spray test and by means of electrochemical corrosion in chloride solutions. Corrosion damage and products were investigated using optical microscopy, scanning electron microscopy and energy dispersive X-ray analysis. The influence of the alloy on the corrosion performance and the mechanism of corrosion protection (cathodic, forming passive layer) of sprayed coatings are discussed. Furthermore it is calculated to what extent thermal spraying can be an economical addition to hot zinc dipping for steel structures. In this way industry ought to be given an economical and easy to use process for new zinc-coatings or repairing existing zinc-coatings.
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