Method for Passivating a Metal Surface, Particularly an Aluminum Surface

Abstract

A method for the passivation of a metal surface, in particular an aluminum surface, is provided and includes the following steps: a) providing a metal surface for passivation; b) bringing the metal surface from step a) in contact with an activating solution to obtain an activated metal surface, which contains the following: a first acid comprising aliphatic sulfonic acid, aromatic sulfonic acid, sulfamic acid, or a mixture thereof, at least one other acid comprising dicarboxylic acid, polycarboxylic acid, or a mixture thereof, zirconyl nitrate, and fluoride ions; c) bringing the metal surface activated in step b) in contact with water to generate a passivation coating, wherein the water is at a temperature of at least 80° C., preferably at least 90° C.

Dependencies are inferred from the claim text.