PBF{\hbox-}LB of large{\hbox-}area magnesium WE43 structures surface{\hbox-}enhancedby plasma electrolytic oxidation
Progress in Additive Manufacturing / Special Issue: RapidTech
9
683-694
2024
Type: Zeitschriftenaufsatz (reviewed)
Abstract
Due to the improved understanding of the industry, additive manufacturing processes are becoming increasingly accepted for
fabricating complex lightweight components. The focus of the magnesium research is primarily on small implant structures.
Due to challenges in the manufacturing process and oxidation behavior, large structures for lightweight components are
mainly fabricated with titanium. This paper expands the scope of the laser-based powder bed fusion (PBF-LB) of larger-area
magnesium parts with surface enhancement using the Ultraceramic® by the plasma electrolytic oxidation (PEO). For this
purpose, the PBF-LB process development for cylindric structures with a diameter of 31 mm is carried out. The processing
strategies are adapted for a crack and porosity free process. To mitigate the inherent oxidation of the biodegradable WE43
and reduce the surface wear in tribologically challenging applications, the additively manufactured magnesium is modified
by the Ultraceramic®. The thickness of the ceramic surface could be tailored between 10 and 40 μm, while enclosing adhering
powder particles of the PBF. Electrochemical impedance spectroscopy showed an increased resistance to corrosion by
an increased modulus |Z0.01| by a factor of 658. The tribological behavior was characterized in pin-on-disc experiments and
showed a decrease of surface wear down to 7.9 × 10–
6 mm3/
N·m up to a Hertzian pressure of 720 MPa tested by a tungsten
carbide ball. Therefore, the synthesis of the PBF-LB of large-area magnesium parts and the PEO of the Ultraceramic
® enables
lightweight components for challenging oxidative and tribological conditions in real world applications.