Studio del processo di anodizzazione dei componenti in lega di alluminio AlSi10Mg prodotti mediante fabbricazione additiva

The present thesis work aims to investigate the electrochemical anodization process applied to components, based on the AlSi10Mg aluminum alloy produced using Selective Laser Melting (SLM) in the Additive Manufacturing (AM) technology. Various tests were conducted using different anodic processes, ranging from hard anodization to natural and coloured ones. Standard process parameters typically used for treating components manufactured through traditional technologies, have been employed. Additional test processes were carried out to improve the quality of the oxide layer, by modifying process parameters, including electrolyte concentration, applied potential, and treatment time. Produced samples underwent characterization using microscopy, to evaluate thickness, substrate adhesion, and composition. Moreover, corrosion resistance and hardness properties were evaluated to determine the quality of the oxide and the applicability of the process. Due to the high roughness achieved in additive manufacturing processes, analyses were conducted on both pre-treated polished surfaces and rough surfaces (i.e. processed solely by shot blasting) to evaluate properties under real conditions. This study allowed a deep understanding of the behaviour of AM components during the anodic process, highlighting issues related to the presence of silicon in the alloy, which, combined with the very fine microstructure typical of SLM technology, significantly limited the growth of the anodic layer. The activities were carried out in collaboration between the University of Turin, where characterization activities were performed, the Industry Manufacturing Competence Center 4.0 (CIM 4.0), specialized in additive manufacturing, where the samples to be treated were selected and produced, and an external company, responsible for carrying out the desired anodic treatments.