Lightweight structures produced by Additive Manufacturing (AM) technology such as Selectively Laser Melting process (SLM) enables the fabrication of 3D structures with high degree of freedom and lightweight. The printed component can be tailored to meet specific properties and render possible applications for industries such as aerospace and automotive. Here, AlSi10Mg is one of the alloys that is currently used for SLM processes and investigated extensively. Although, the research to improve the strength of AM aluminum alloy components is rapidly progressing, the corrosion protection is hardly addressed in this field.

Plasma Electrolytic Oxidation (PEO) is an advanced electrolytical process for surface treatment of light metals such as aluminum, magnesium and titanium. This process produces an oxide ceramic-like layer, which is extremely hard but also ductile and which improves the corrosion and wear behavior significantly.

The aim of this study is to understand the corrosion behavior of 3D printed AiSi10Mg alloy on the one hand and to improve its corrosion resistance on the other hand. For this reason, the properties of the CERANOD® - PEO coating on an AlSi10Mg alloy produced by SLM have been investigated on different AM surfaces i.e., as-built, mechanical polished and stress relieved specimens. The corrosion performance of these surfaces was analyzed by using electrochemical impedance spectroscopy (EIS) and long-time immersion tests. Moreover, the microstructure and morphology of the resulting coatings was characterized by SEM/EDS as well as the corrosive attacks.

The results exhibit a high amount of selective corrosion attacks in the case of the uncoated specimens, while the PEO process on the Aluminum AM surfaces leads to enclosed homogeneous coatings by even protecting the material’s pores, which are typically for the AM process. Thereby, a high corrosion protection could be achieved by PEO surfaces, making this technology a promising candidate to unleash the whole potential of 3D light metal printing.