Anodic oxidation of the AlCu4Mg1 aluminium alloy with dynamic current control
2016 (English)In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 302, p. 515-522Article in journal (Refereed) Published
Abstract [en]
The anodic oxidation process is a common method for the surface modification of aluminium and its alloys. The increasing application of high-strength aluminium alloys therefore represents a challenge, since alloying elements, amongst them copper, significantly disturb the coating formation during anodising. Hence, flaws arise in the oxide layers and lead to the deterioration of their performance. Recent investigations have indicated the possibility of extenuating the negative influence of the alloying elements on the coating formation by applying time-variable electrical regimes. In case of the current density as the control factor in the coating process, this approach is related to as dynamic current control. For the anodic oxidation of AlCu4Mg1 (EN AW-2024), the effect of dynamic current control on the oxide layer properties is investigated by using a design of experiments (DOE). The parameter variation includes starting ramps, a step-wise change of the current density in the process and pulse current at electrolyte temperatures of 5 °C and 15 °C. A solution of 20 vol% sulphuric acid with an addition of oxalic acid or nitric acid is used as the electrolyte. The produced oxide coatings are examined with regard to their thickness, hardness, their performance in the scratch test and their current density-potential behaviour in diluted NaCl solution. Further, the electrical energy consumption during the anodisation is considered. The results are evaluated with the help of an analysis of variance (ANOVA).
Place, publisher, year, edition, pages
Elsevier, 2016. Vol. 302, p. 515-522
Keywords [en]
Aluminium alloy AlCu4Mg1, Anodic oxidation, Dynamic current control, Hardness, Pitting corrosion, Alloying, Alloying elements, Aluminum, Aluminum alloys, Analysis of variance (ANOVA), Coatings, Current density, Design of experiments, Electric current control, Electrolytes, Energy utilization, High strength alloys, Oxalic acid, Oxidation, Pitting, Protective coatings, Surface treatment, Aluminium and its alloys, Coating formation, Control factors, Dynamic current, Electrical energy consumption, Electrolyte temperature, High strength aluminium alloys, Oxidation process
National Category
Materials Engineering
Identifiers
URN: urn:nbn:se:hj:diva-51168DOI: 10.1016/j.surfcoat.2016.06.043ISI: 000381838400059Scopus ID: 2-s2.0-84976532759OAI: oai:DiVA.org:hj-51168DiVA, id: diva2:1507535
2020-12-082020-12-082020-12-08Bibliographically approved