Coloured aluminium sheets: colours of aluminium alloy sheets of different compositions after oxidation for sale Haomei

2022-12-02

As already mentioned, aluminium alloy sheets of different grades can also be coloured by anodising, resulting in a non-traditional painted aluminium sheet. We have also mentioned that different alloy compositions can also directly change the colour of the anodised aluminium surface. But what exactly are the ingredients that make anodised aluminium reddish, grey or other colours? We would like to introduce the details today, and hope that we can help you in the process of purchasing anodised aluminium sheets and coloured aluminium sheets.

Aluminium alloy contains copper, silicon, iron and other impurities on the surface appearance of the oxide film. The impact on performance is as follows: copper will make the oxide film red, destroy the quality of the electrolyte, increase the oxidation defects; silicon will make the oxide film gray, especially when the content exceeds 4.5%, the impact is more obvious; iron because of its own characteristics, after the anodic oxidation will exist in the form of black spots.

In addition, there are other impurities in the alloy on the appearance of the anodized aluminum plate: 1 ~ 2% manganese aluminum alloy, brown-blue after oxidation, with the increase in the amount of manganese in aluminum, oxidation of the surface colour from brown-blue to dark brown transformation. Aluminium alloys containing 0.6 to 1.5% silicon are grey after oxidation, and when they contain 3 to 6% silicon, they are white-grey. Those containing zinc have a milky colour, those containing chromium have a golden to grey uneven tone and those containing nickel have a light yellow colour. Generally speaking, only aluminium containing magnesium and titanium containing more than 5% gold can be obtained after oxidation as colourless, transparent and bright, shiny and clean coloured aluminium sheets.