Aluminum alloy Ce-Cu composite conversion coating and preparation method thereof

Abstract

The invention provides an aluminum alloy Ce-Cu composite conversion coating, which comprises four elements including Ce, Cu, Al and O, wherein the mass percentage of Ce in the aluminum alloy Ce-Cu composite conversion coating is 5-48%, the mass percentage of Cu is 8-20%, the mass percentage of Al is 20-40%, and the mass percentage of O is 15-35%. The invention further provides a preparation method of the Ce-Cu composite conversion coating, and the preparation method comprises the following steps: 1, pre-treating an aluminum alloy surface; 2, converting the pre-treated aluminum alloy in conversion treatment liquid to obtain the aluminum alloy Ce-Cu composite conversion coating. The aluminum alloy Ce-Cu composite conversion coating, provided by the invention, has the advantages of simple preparation process, low production cost, easily controlled technique parameters, short conversion time and strong repeatability; the aluminum alloy Ce-Cu composite conversion coating prepared by the preparation method is compact and firmly combined with an aluminum alloy substrate, and has excellent anti-corrosion protection performance.

Description

technical field [0001] The invention belongs to the technical field of aluminum alloy surface engineering, and in particular relates to an aluminum alloy Ce-Cu composite conversion film and a preparation method thereof. Background technique [0002] Chemical oxidation treatment technology is the most commonly used method for corrosion protection of aluminum alloys. [0003] Document 1 (Yu Xingwen, Li Ning, Zhou Yuhong, etc. Rare earth conversion coatings on metal surfaces. Materials Herald, 1998, 12(4): 24-24) mentioned Hinton and Arnott from the Materials Science Department of the Australian Aeronautical Research Laboratory in the early 1980s. Put Ce 3+ As a corrosion inhibitor of 7075 aluminum alloy in NaCl solution, the corrosion rate of 7075 aluminum alloy is reduced to 1 / 10 of the original. Later, Hinton et al. pre-dipped the aluminum alloy in CeCl 3 In the solution, a layer of straw yellow film is formed, and the corrosion resistance of this film is much higher than...

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Problems solved by technology

[0007] Document 4 (Zhang Junjun, Li Wenfang, Du Jun. Preparation and properties of Ce-Mn conversion film on the surface of aluminum alloy at room temperature. 3 ) 3 and KMnO 4 The Ce-Mn conversion film is prepared by the rare earth conversion film process of the main salt, but the film-forming efficiency of the conversion treatment liquid of this process is low, it takes a long time, and the conversion temperature is high, which is difficult to meet the needs of industrial production; this process also uses NaF As a film-forming accelerator, accelerate the film-forming rate of Ce-Mn conversion film, improve film-forming efficiency, and realize rapid film-forming at room temperature

[0008] Although there have been preliminary studies on rare earth conversion coatings on the surface of aluminum alloys, so far, no reports have been found on the Ce-Cu composite conversion coatings on aluminum alloys and their preparation methods.

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