METHOD FOR PRODUCING AN ALUMINIUM COMPONENT HAVING A COLOURED SURFACE
A method for producing an aluminium component having a coloured surface, and comprises the steps of anodizing the surface of the component and applying the colouring component by electrolysis. The method is characterized in that the electrolyte comprises an Sn salt and a further salt of a divalent metal. Through the combination of two or more metal salts in the electrolytic colouring of anodized layers, a dense and intensely coloured coloration can be obtained on the aluminium surface.
1 . A method for producing an aluminium component having a coloured surface, comprising the steps of:
anodizing the surface of the component,
applying the colouring component by electrolysis of an electrolyte,
characterized in that the electrolyte comprises an Sn salt and a further salt of a divalent metal.
2 . The method of claim 1 , characterized in that the further salt is selected from salts of Ni, Co, Cu, Mn and/or Fe.
3 . The method of claim 1 , characterized in that the Sn salt and the further salt are used in the form of the sulfates.
4 . The method of claim 1 , characterized in that the Sn salt is SnSO4 and the salt of a divalent metal is NiSO4, wherein a black colour surface is obtained.
5 . The method of claim 1 , characterized in that the Sn salt is in a concentration of 0.1 to 15 g/l in the electrolyte.
6 . The method of claim 1 , characterized in that the further salt is in a concentration of 2 to 200 g/l.
7 . The method of claim 1 , characterized in that the Sn salt and the further salt are in a ratio of 1:20 to 1:200 in the electrolyte.
8 . The method of claim 1 , characterized in that the electrolyte has a pH of <1 to 2.
9 . The method of claim 1 , characterized in that the electrolysis is carried out at a temperature of room temperature to 22° C.
10 . The method of claim 1 , characterized in that electrolysis is carried out with alternating voltage.
11 . The method of claim 1 , characterized in that the component in a downstream step of the method is provided with a sol/gel coating.
12 . The method of claim 1 , characterized in that a black surface is produced.
13 . The method of claim 1 , characterized in that the layer applied electrolytically has a thickness of 6 to 11 μm, preferably of 6 to 10 μm.
14 . The method of claim 1 , further comprising the step of hot deionized-water densification.
15 . The method of claim 1 , characterized in that the electrolyte further comprises one or more of the following: sulfuric acid, iron(II) sulfate, sulfophthalic acid, and sulfosalicylic acid.
16 . A component of aluminium which has a black surface and has been produced according to the steps of: anodizing the surface of the component, applying the colouring component by electrolysis, characterized in that the electrolyte comprises an Sn salt and a further salt of a divalent metal.
17 . The component of claim 16 , characterized in that the further salt of a divalent metal is a Ni salt.
18 . The component of claim 16 , further comprising a sol gel coating layer.
19 . The component of claim 16 , wherein component is part of the body of a motor vehicle.
20 . The component of claim 16 , wherein the component is an ancillary component for mounting on the body of a motor vehicle.