Anodisation with dynamic current control for tailored alumina coatings

18th Chemnitz Seminar on Materials Engineering – 18. Werkstofftechnisches Kolloquium

Sieber, M.^1 ; Althöfer, I.^1 ; Höhlich, D.^1 ; Scharf, I.^1 ; Böttger, D.^2 ; Böttger, S.^2 ; Böttger, E.^2 ; Lampke, T.^1

Materials and Surface Engineering Group, Institute of Materials Science and Engineering, Technische Universität Chemnitz, Chemnitz

D-09125, Germany^1

Eckhard Böttger Oberflächenveredlung, Sehmatal-Neudorf

D-09465, Germany^2

关键词: Aluminium and its alloys;    Coating properties;    Corrosion and wear resistance;    Electrical energy consumption;    Electrical process;    Electrolyte compositions;    Oxidation process;    Statistical significance;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/118/1/012038/pdf
DOI  :  10.1088/1757-899X/118/1/012038

来源: IOP

【 摘 要 】

The anodic oxidation process is commonly used to refine the surface of aluminium and its alloys. Compared to the substrate, the alumina layers produced by anodising exhibit an increased hardness and chemical resistance. Thus, the corrosion and wear resistance are generally improved. The coatings are also electrically isolating and may serve decorative purposes. Applying a time-variant, dynamic electrical process control by pulse-current or current-steps is a promising approach to improve the coating properties, which is partially deployed in an industrial scale. In the present work, the influence of dynamic electrical process control on the coating properties is examined by means of a design of experiments (DOE). The effects of various electrolyte compositions and temperatures as well as processing time are considered with regard to coating thickness, hardness, wear resistance and the electrical energy consumption during the formation of the coatings. Information about the statistical significance of the effects of the parameters on the considered properties is obtained by an analysis of variance (ANOVA).