A method of forming a cured film on an aluminum substrate includes depositing a film formed from a sol-gel coating composition onto the aluminum substrate without disposing a conversion coating composition onto the aluminum substrate. The method also includes, after depositing, curing the film. A coating system includes an aluminum substrate having a surface and a cured film disposed on and in contact with the surface. The cured film is formed from a sol-gel coating composition. The coating system is free from a layer formed from a conversion coating composition.

A method of forming a cured film on an aluminum substrate includes depositing a film formed from a sol-gel coating composition onto the aluminum substrate without disposing a conversion coating composition onto the aluminum substrate. The method also includes, after depositing, curing the film. A coating system includes an aluminum substrate having a surface and a cured film disposed on and in contact with the surface. The cured film is formed from a sol-gel coating composition. The coating system is free from a layer formed from a conversion coating composition.

A method for the surface treatment of flat products made of aluminium alloys. The method includes pickling the flat product, in particular for degreasing the flat product. The method includes carrying out a colour measurement on the surface of the flat product to determine at least one measured colour value after pickling the flat product. The method includes generating output information on the basis of the at least one measured colour value. The output information is indicative of compliance with at least one rule for the measured colour value and outputting or triggering the output of the output information. The invention further relates to a device for the surface treatment of flat products made of aluminium alloys and to a use of a colorimeter which is configured to determine at least one measured colour value in a surface treatment of flat products made of aluminium alloys.

A method for the surface treatment of flat products made of aluminium alloys. The method includes pickling the flat product, in particular for degreasing the flat product. The method includes carrying out a colour measurement on the surface of the flat product to determine at least one measured colour value after pickling the flat product. The method includes generating output information on the basis of the at least one measured colour value. The output information is indicative of compliance with at least one rule for the measured colour value and outputting or triggering the output of the output information. The invention further relates to a device for the surface treatment of flat products made of aluminium alloys and to a use of a colorimeter which is configured to determine at least one measured colour value in a surface treatment of flat products made of aluminium alloys.

A metal article comprises two metals, and a first hole and an oxide layer are set correspondingly on the surfaces of the two metals. To avoid the electrolytic corrosion on the interface between the two metals during the formation of the first hole, the disclosure provides a method of manufacturing the metal article. By putting a metal substrate in a first electrolyte including an etching agent and a passivating agent and applying electricity on the metal substrate, the metal article with the first hole is formed without electrolytic corrosion. The disclosure also provides a metal composite, which is formed by setting a material part in the first hole of the metal article.

A process for providing a surface of aluminum containing materials with a chromate-free protective coating includes degreasing a surface of an aluminum containing material to produce a degreased surface, treating the degreased surface in a high alkaline treatment immediately subsequent to the degreasing to produce an alkaline treated surface having smut on the surface, and treating the alkaline treated smut surface with a hydrothermal treatment immediately subsequent to the high alkaline treatment.

A process for providing a surface of aluminum containing materials with a chromate-free protective coating includes degreasing a surface of an aluminum containing material to produce a degreased surface, treating the degreased surface in a high alkaline treatment immediately subsequent to the degreasing to produce an alkaline treated surface having smut on the surface, and treating the alkaline treated smut surface with a hydrothermal treatment immediately subsequent to the high alkaline treatment.

Described herein is a water-based, alkaline cleaner concentrate for producing a cleaner for metallic surfaces, the concentrate including a) at least one (meth)acrylic acid homopolymer having a weight-average molar mass in the range from 3 000 to 19 000 g/mol and b) at least one (meth)acrylic acid copolymer having a weight-average molar mass in the range from 50 000 to 100 000 g/mol. Also described herein are a corresponding cleaner for metallic surfaces with reduced pickling erosion, a process for anticorrosive treatment of metallic surfaces that includes a corresponding cleaning step, a metallic surface obtained by the process, and a method of use thereof in the sector of the metalworking industries.

Metallic substrate treatment methods and articles comprising a phosphonate functionalized layer are provided. The method comprises contacting a metallic substrate comprising at least one of aluminum and an aluminum alloy with a fluid to form a phosphonate functionalized layer on at least a region of the metallic substrate. The fluid comprises at least one of a phosphonate containing acid and a derivative thereof. At least one of the phosphonate containing acid and the derivative thereof comprises a pKa of a first acidic proton. The fluid comprises a pH at least 0.5 pH value greater than the pKa of the first acidic proton. The article comprises a metallic substrate comprising aluminum or an aluminum alloy and a phosphonate functionalized layer on at least a region of the metallic substrate.

Metallic substrate treatment methods and articles comprising a phosphonate functionalized layer are provided. The method comprises contacting a metallic substrate comprising at least one of aluminum and an aluminum alloy with a fluid to form a phosphonate functionalized layer on at least a region of the metallic substrate. The fluid comprises at least one of a phosphonate containing acid and a derivative thereof. At least one of the phosphonate containing acid and the derivative thereof comprises a pKa of a first acidic proton. The fluid comprises a pH at least 0.5 pH value greater than the pKa of the first acidic proton. The article comprises a metallic substrate comprising aluminum or an aluminum alloy and a phosphonate functionalized layer on at least a region of the metallic substrate.