The Effect of Hard Anodizing Pre‐Process on the Tribological Performance of CrN / CrAlN Coating on AA6063

ABSTRACT

This study investigates the effect of hard anodizing as a pre‐treatment for a CrN/CrAlN coating deposited by cathodic arc evaporation‐physical vapor deposition (CAE‐PVD) on AA6063‐T6 aluminum alloy. The main objective of this research is to evaluate the influence of the simultaneous application of an anodized layer and a CrN/CrAlN coating on the tribological properties of the samples. For the analysis of the results, characterization techniques such as XRD and FESEM were used. Additionally, Rockwell‐C adhesion, pin‐on‐disk wear, and Vickers microhardness tests were conducted. The roughness of the sole CrN/CrAlN coating surface was 0.6 ± 0.1 μm. The sole CrN/CrAlN coating showed a lower wear rate than the substrate, which is attributed to the detachment of hard CrN particles acting as third‐body abrasives during the wear process. In general, this study demonstrates that the duplex process of anodizing and CrN/CrAlN coating can enhance certain surface properties, including hardness, by nearly five times compared with the sole CrN/CrAlN coating and by more than 1.5 times compared with the sole anodized layer. In terms of wear behavior, this combination exhibits more than three times better wear performance than the sole PVD coating, although its wear rate is approximately 2.5 times higher than that of the sole anodized layer.