Adhesion and corrosive delamination of epoxy films on chemically etched ZnMgAl-alloy coatings

• Published in: Materials and corrosion Vol. 67; no. 10; pp. 1020 - 1026
• Main Authors: Pohl, K., Ozcan, O., Voigt, M., Grundmeier, G.
• Format: Journal Article
• Language: English
• Published: Weinheim Blackwell Publishing Ltd 01.10.2016; Wiley Subscription Services, Inc
• Subjects: Adhesion tests; Adhesives; Cleaning; Coating effects; Delaminating; Delamination; Peel tests; peel-test; pretreatment; scanning Kelvin probe; Spectroscopic analysis; XPS; ZnMgAl-alloy coating
• ISSN: 0947-5117; 1521-4176
• DOI: 10.1002/maco.201608968

The effect of alkaline and acidic pretreatment steps on the surface chemical composition and adhesion properties of ZnMgAl‐alloy coated steel was investigated by means of spectroscopic methods, scanning Kelvin probe (SKP) and peel test measurements. The spectroscopic results indicate that the surface film composition can be adjusted by the wet‐chemical treatment. To study the corresponding surface adhesive properties, the samples were coated with an epoxy amine adhesive. Peel tests under humid conditions indicated an increased interaction between the acidic pre‐treated surface and the adhesive. The results of the SKP analysis show that the acidic cleaned substrates have the highest resistance to delamination, which can be explained by the shift of the interfacial electrode potential. The effect of alkaline and acidic pretreatment steps on the surface chemical composition and adhesion properties of ZnMgAl‐alloy coated steel was investigated by means of spectroscopic methods, scanning Kelvin probe (SKP) and peel test measurements. The results of the SKP analysis show that the acidic cleaned substrates have the highest resistance to delamination.