Method for corrosion-protective serial surface treatment of metallic components

US9932677B2 · kind B2 · utility

Assignee

• Henkel AG & Co. KGaA · DE

Inventors

• Jan-Willem Brouwer · Willich, DE
• Frank-Oliver Pilarek
• Kirsten Agnes Lill · Goldkronach, DE
• Fernando Jose Resano Artalejo · Dressendorf, DE
• Natascha Henze · Leverkusen, DE

Key dates

• Filing date: Mar 3, 2015
• Grant date: Apr 3, 2018
• Expiry date: Jan 2, 2036

Classification

• Technology area (CPC G): Physics
• CPC primary: G05D21/02
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

The present invention relates to a method for serial surface treatment of metallic components comprising aluminum surfaces, wherein an alkaline pretreatment is followed by a conversion treatment. According to the invention, the intention during the alkaline pretreatment is that a maximum value for the concentration of dissolved zinc is not exceeded, in order to ensure a sufficient quality of the corrosion-protective coating on the aluminum surface of the components following the surface treatment. In a preferred embodiment, the content of dissolved zinc is effectively held below the respective bath-typical maximum value of dissolved zinc by the addition of compounds constituting a source of sulfide ions. The functionality of the surface treatment can be additionally increased by likewise controlling the content of dissolved aluminum in the alkaline pretreatment such that, by adding compounds constituting a source for silicate anions, a threshold value for dissolved aluminum is not exceeded.