High strength aluminum alloy anodizing electrolyte, preparation method of high strength aluminum alloy anode oxide film and high strength aluminum alloy workpiece

Abstract

The invention relates to the metal surface treatment technology field, in particular to a high strength aluminum alloy anodizing electrolyte, a preparation method of a high strength aluminum alloy anode oxide film and a high strength aluminum alloy workpiece. The high strength aluminum alloy anodizing electrolyte contains 0.1-0.2mol / L of phytic acid. Oxidation reaction can occur on the surface ofa high strength aluminum alloy after being electrified in a phytic acid solution, and the anode oxide film 3-5[mu]m in thickness can be obtained by regulating the concentration of the phytic acid andoxidation voltage, and then corrosion resistance of the high strength aluminum alloy can be significantly improved on the premise that a film layer is thin and cannot influence fatigue performance ofa matrix, and furthermore the high strength aluminum alloy anodizing electrolyte is especially suitable for improving corrosion resistance of high strength aluminum alloys of Al-Cu, Al-Mg-Si and Al-Zn-Mg-Cu series; and additionally, the natural plant extract phytic acid is used, and therefore the high strength aluminum alloy anodizing electrolyte is economical and practical, environmentally friendly and free from toxicity, and simple and convenient in wastewater treatment process, and has good application value and good economic and social benefits.

Description

technical field [0001] The invention relates to the technical field of metal surface treatment, in particular to a high-strength aluminum alloy anodic oxidation electrolyte, a method for preparing a high-strength aluminum alloy anodic oxidation film, and a high-strength aluminum alloy workpiece. Background technique [0002] Al-Cu(2×××) series and Al-Zn-Mg-Cu(7×××) series aluminum alloys have the characteristics of low density, high specific strength and hardness, and excellent plastic processing performance. Therefore, they are widely used In aviation, construction and transportation and other fields. However, 2××× and 7××× aluminum alloys are very sensitive in corrosive medium environments, and are easily affected by various corrosions (such as pitting corrosion, exfoliation, intergranular corrosion, and stress corrosion, etc.), affecting aluminum alloy workpieces. performance and lifespan. Therefore, proper surface treatment must be used to improve the protective perfor...

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Problems solved by technology

[0003] At present, anodic oxidation is an important means to improve the corrosion resistance of 2××× and 7××× series aluminum alloys. Among them, sulfuric acid anodic oxidation, chromic acid anodic oxidation and boric sulfuric acid anodic oxidation are the most widely used in the aviation industry, but these There are certain deficiencies in the process: the chromic acid anodic oxidation film layer is dense, the porosity is low, and the fatigue strength of the substrate is not damaged, but Cr(VI) pollutes the environment, which leads to its use being restricted; although the sulfuric acid anodic oxidation has little pollution, However, it will reduce the fatigue resistance of the base material, and the concentration of sulfuric acid is relatively high, so it is not suitable for 2××× alloys with high Cu content; while the boron-sulfuric acid anodizing process does not have the above-mentioned shortcomings, but it is restricted by Boeing’s patent. Difficult to use on a large scale

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