Method for preparing black oxidation film on 7A04 aluminum alloy surface

Abstract

The invention discloses a method for preparing a black oxidation film on 7A04 aluminum alloy surface. The method comprises the following steps of grinding the surface of the aluminum alloy workpiece to be treated on an abrasive paper, cleaning and drying so as to prepare a cleaned aluminum alloy workpiece; carrying out alkali washing on the cleaned aluminum alloy workpiece at 60 DEG C for 50-80 seconds, then carrying out acid washing at normal temperature for 20-40 seconds, cleaning with deionized water and absolute ethyl alcohol and airing so as to prepare the pre-treated aluminum alloy workpiece; placing the pre-treated aluminum alloy workpiece in an electrolyte for primary electrolysis, preparing a uniform and transparent anode oxide film on the surface of the aluminum alloy workpiece;placing the aluminum alloy workpiece subjected to primary electrolysis in a coloring solution for secondary electrolysis so as to prepare a uniform black oxidation film on the surface of the aluminumalloy workpiece. According to the method, the prepared film is compact in film layer, good in color retention, weather resistance and light resistance, long in service life, simple in processing technology, and low in processing energy consumption.

Description

technical field [0001] The invention relates to the technical field of aluminum alloy coloring, in particular to a method for preparing a black oxide film on the surface of a 7A04 aluminum alloy. Background technique [0002] At present, in the surface coloring technology of aluminum and aluminum alloy products, the black film layer is widely used in navigation, optical instruments, building decoration materials and other fields because of its unique optical function and decorative performance. [0003] In the prior art, the aluminum alloy colored oxide film includes integral colored film, dyed film, etc., but the dyed film has poor weather resistance and light resistance, short service life, and the integral colored film has complicated processing technology and high processing energy consumption. Contents of the invention [0004] Aiming at the above-mentioned deficiencies in the prior art, the present invention provides a method for preparing a black oxide film on the s...

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Problems solved by technology

[0003] In the prior art, the oxide film colored by aluminum alloy includes integral colored film, dyed film, etc., but the weather resistance and light resistance of the dyed film are poor, the service life is short, the processing technology of the integral colored film is complicated, and the processing energy consumption is high.

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