Patent Number: 6,165,630

Title: Galvanized aluminum sheet

Abstract: A method for applying a zinc layer onto an aluminum or aluminum alloy sheet, comprising pretreating the surface and applying the layer by electrolytic galvanizing, the pretreating comprises electrochemical graining of the surface, for example in a solution having a pH less than 3 with an alternating current applied between the sheet and an electrode. In an alternative method, the pretreating includes applying a preliminary zinc layer by immersing the surface in a zinc-containing alkaline solution, applying a potential to the sheet and reversing the polarity of said potential at least once. The sheets are useful for building cladding sheets and automotive panels.

Inventors: Gehlhaar; Horst (Andernach, DE), Spanjers; Martinus Godefridus Johannes (IJmuiden, NL), Mooij; Joop Nicolaas (Castricum, NL), Van Der Meer; Wilhelmus Jacobus (Amsterdam, NL)

Assignee: Corus Bausysteme GmbH

International Classification: C25D 5/44 (20060101); C25D 5/34 (20060101); C25F 3/04 (20060101); C25F 3/00 (20060101); C25D 005/44 (); C25F 003/04 ()

Expiration Date: 12/26/2013