Composition and method for the chromium-free pretreatment of aluminium surfaces

• Main Authors: Wendel, Thomas, Maurus, Norbert, Hellmers, Heiko
• Format: Patent
• Language: English
• Published: 27.06.2023
• Subjects: ALLOYS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; FERROUS OR NON-FERROUS ALLOYS; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TREATMENT OF ALLOYS OR NON-FERROUS METALS

Described herein is an aqueous, chromium-free composition for a pretreatment of aluminum surfaces, which includes at least one water-soluble phosphorus compound, at least one water-soluble zirconium compound, at least one water-soluble titanium compound, and at least one water-soluble molybdenum compound, a phosphorus compound content being in a range from 15 to 50 mg/l (calculated as phosphorus), a zirconium compound content being in a range from 400 to 600 mg/l (calculated as metal), a titanium compound content being in a range from 85 to 400 mg/l (calculated as metal), and a molybdenum compound content being in a range from 40 to 150 mg/l (calculated as metal). Also described herein are a corresponding method and a correspondingly pretreated component or strip.