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| Abstract No.: |
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Scheduled at:
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Tuesday, May 10, 2016, Auditorium 4:45 PM
Young Professionals Session
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| Title: |
Bi-layer thermal spray coatings: A critical approach to extend the service-life of metallic components
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| Authors: |
Esmaeil Sadeghimeresht* / University West, Sweden
Nicolaie Markocsan/ Production Technology Center, University West, Sweden
Per Nylén/ Production Technology Center, University West, Sweden
Stefan Björklund/ Production Technology Center, University West, Sweden
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| Abstract: |
Corrosion is a common problem for many metallic components used today in a wide range of industries. Thermal spraying is a promising approach to properly protect the metallic structure from the deleterious effects of the environment that surrounds it. In this study, three types of coating systems (A: single layer of Cr2C3-NiCr, B: Ni/Cr2C3-NiCr and C: NiCr/Cr2C3-NiCr) were deposited using HVAF process. Electrochemical tests were employed to investigate the corrosion susceptibility of the above systems. OCP, polarization and EIS tests were performed in 3.5 wt.% NaCl solution at 25°C. Results showed that bi-layer coatings exhibited a better corrosion resistance than the single-layer coating. While coating system A demonstrated some signs of pitting due to the penetration of tiny chloride ions through the defects of the coating, which eventually led to the destruction of the substrate close to the interface, coating systems B and C showed much better anti-corrosion behavior. Moreover, the results confirmed that gradual changes of the composition from the top coating to substrate reduced the possibility of galvanic corrosion. SEM, EDAX, and XRD were used to characterize the corrosion products along the surface and the cross-section of specimens.
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