Optimierung der Anodisierbarkeit bei Aluminiumautomatenlegierungen

Free-cutting aluminium alloys contain beside the typical strengthening alloying elements so called free-cutting phases which give benefits to the machining behaviour of the alloys. Compared to pure aluminium, they have lower melting points and less hardness. The third requirement in this context is their indissolubility in the aluminium matrix. Examples are Bi, Cd, In and Sn. For the commercial anodic treatment, most of the alloying elements are problematic. They could probably generate intermetallic phases in the anodic film, be in charge of building laminate layers, provoke the appearance of blisters, or produce other defects in the protecting layer. Current research about the anodization process at the Institute of Nonferrous Metallurgy, University of Leoben, covers a wide scope of topics, ranging from the machining processes to the final sealing step of anodic treatments and intends to optimize the whole product-chain with attention to sustainable requirements.