Magnesium and its alloys are the structural lightweight metals with the highest strength-to-density ratio, leading to extreme weight reduction up to 40 % in comparison to Aluminium alloys. Still, additive manufacturing of Mg components is challenging since it is reactive and aims to oxidize very fast. Nevertheless, using the appropriate equipment and parameters, powder bed fusion- Laser beam (PBF-LB) technology can be used to print 3D parts of Mg alloys. This possibility increases the lightweight potential, since material saving in production can be combined with outcoming components leading to an overall energy reduction due to reduced weight. Components with complex 3D geometries and reduced weight are of increasing interest in aerospace, automotive and machining industries.
However, high corrosion tendency of Mg and its alloys limits the application extremely. Galvanic corrosion occurs easily at this metal since its electrochemical potential is lower compared to other metals. An appropriate environmentally friendly surface technique to prevent corrosion on lightweight metals is the PEO process (plasma-electrolytical oxidation), which converts the lightweight surface to ceramic-like oxides, leading to high corrosion and wear protection.
The consortium of the CAMM project, the Laserzentrum Hannover and ELB, decided to develop the PBF-LB technique along with a suitable PEO process to discover the best interplay of process parameters to match the properties for any desired application.
In this talk we report the enhanced surface properties achieved on 3D-printed Mg surfaces refined with the Ultraceramic® PEO process considering the improved mechanical performance being tested by Pin-on-Disc and microhardness testing. Furthermore, the corrosion protection will be demonstrated with help of electrochemical testing methods. Resulting surfaces and their cross sections are examined by SEM and EDS technologies to analyze the existing wear and corrosion occurrences, comparing both, the unprotected and the PEO protected surfaces.