Recent advances in energy efficient PEO processing of aluminium alloys
(1. Departamento de Ciencia de Materiales, Facultad de Ciencias Químicas, Universidad Complutense, 28040 Madrid, Spain;
2. Helmholtz-Zentrum Geesthacht, Magnesium Innovation Centre, Institute of Materials Research, Max-Planck-Str. 1, D-21502 Geesthacht, Germany)
2. Helmholtz-Zentrum Geesthacht, Magnesium Innovation Centre, Institute of Materials Research, Max-Planck-Str. 1, D-21502 Geesthacht, Germany)
Abstract: Plasma electrolytic oxidation (PEO) coatings developed under voltage-controlled mode on various commercial wrought, gravity cast and rheocast aluminium alloys were discussed with respect to enhancement of their tribological and corrosion performance and minimization of the PEO energy consumption. It is demonstrated that use of conventional porous anodic film precursors reduces the PEO energy consumption by up to 50%. The wear of 6082 alloy with PEO coatings with added α-Al2O3 particles is two times lower compared with electrolytic hard chrome. The long-term corrosion resistance of the PEO-coated A356 rheocast alloy is enhanced via use of a precursor and hydrophobic post-treatment.
Key words: aluminium; anodizing; plasma electrolytic oxidation; wear; corrosion