Interplay between Microstructure and Anodizability in Aluminum Alloy Brake Calipers

The manuscript proposes a fundamental investigation regarding the corrosion resistance of anodized EN-AC-42200 Aluminum alloy specimens, showing different microstructures. In particular, the microstructures are analyzed in terms of secondary dendrite arm spacing (SDAS), while the corrosion resistance of anodized samples is evaluated by using electrochemical noise measurements (ENM) and associated Noise Resistance (R_n) values. Specimens with five different SDAS values are considered in order to discuss the interplay among: a) microstructure of the alloy; b) anodic layer morphology; and c) corrosion protection of the anodic layer. An inverse proportionality between SDAS value and corrosion resistance is demonstrated.