Cailiao Baohu (Nov 2022)

Analysis on the Effects of Process Parameters of HEDP Anodic Oxidation on the Surface of 7075 Aluminum Alloy

  • YANG Kun, SUN Xiaolan, HAN Dongning, ZHAO Dong, LUO Jian

DOI
https://doi.org/10.16577/j.issn.1001-1560.2022.0319
Journal volume & issue
Vol. 55, no. 11
pp. 124 – 127

Abstract

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The anodic oxidation treatment on aluminum alloy using HEDP (hydroxyethylidene diphosphonic acid) as the electrolyte additive could significantly improve the corrosion resistance of the parts and be helpful for their use in marine conditions. The optimum process parameters of HEDP anodic oxidation were determined by orthogonal test and single factor test: a HEDP concentration of 0.3 mol/L, a temperature of 20～30 ℃, a current density of 0.83 A/dm2, and an oxidation time of 60 min. Moreover, the influences of various process parameters on the film microstructure were analyzed. Based on the morphology of the anodic oxide coating prepared using the optimum process parameters, the thickness of blocking layer was obtained, which was further compared with the thickness of sulfuric acid anodic blocking layer.

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