Improving corrosion stability of Zn[sbnd]Al[sbnd]Mg by alloying for protection of car bodiesShow others and affiliations
2016 (English)In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 306, p. 439-447Article in journal (Refereed) Published
Abstract [en]
Aluminium and magnesium are known for their ability to improve corrosion performance of zinc coatings used for steel protection in automotive applications. To investigate the inhibiting properties of other elements, series of model Zn[sbnd]X, Zn[sbnd]Al[sbnd]X, Zn[sbnd]Mg[sbnd]X and Zn[sbnd]Al[sbnd]Mg[sbnd]X alloys containing 0.2–2 wt% of titanium, mischmetal (mixture of cerium and other lanthanides), zirconium, molybdenum, chromium, boron, gallium, indium, copper, nickel, calcium, manganese and silicon were prepared and their corrosion performance in a cyclic accelerated test and at a marine field site and the ability to provide galvanic protection to steel in defects were characterized. On openly exposed surfaces, none of the investigated elements showed stronger inhibiting effect on atmospheric corrosion than Al and Mg. When exposed to marine climate, it was beneficial to combine Al and Mg. The corrosion stability of Zn[sbnd]Al[sbnd]Mg was further improved by addition of a fourth element. Quaternary Zn[sbnd]Al[sbnd]Mg[sbnd]X alloys outperformed binary Zn[sbnd]X and ternary Zn[sbnd]Al[sbnd]X and Zn[sbnd]Mg[sbnd]X alloys. In average, mass loss was 4-fold higher in confined zones simulating hem flanges. Strong inhibition with Mg and detrimental effects of Al on corrosion in confined zones was found. Several quaternary Zn[sbnd]Al[sbnd]Mg[sbnd]X alloys with improved corrosion stability in both open and confined configurations were identified
Place, publisher, year, edition, pages
Elsevier B.V. , 2016. Vol. 306, p. 439-447
Keywords [en]
Alloy coatings, Atmospheric corrosion, Hem flange protection, Hot dip galvanizing, Aluminum, Binary alloys, Coatings, Corrosion, Flanges, Magnesium, Zinc, Zinc coatings, Automotive applications, Confined configuration, Corrosion performance, Corrosion stability, Galvanic protection, Hot-dip galvanizing, Aluminum alloys
National Category
Natural Sciences
Identifiers
URN: urn:nbn:se:ri:diva-40021DOI: 10.1016/j.surfcoat.2016.03.062Scopus ID: 2-s2.0-84961964255OAI: oai:DiVA.org:ri-40021DiVA, id: diva2:1359375
2019-10-092019-10-092025-09-23Bibliographically approved