• The MSCA Postdoctoral Fellowship ‘MACS’ project demonstrates the successful additive manufacturing of magnesium alloys and significant improvements in their corrosion resistance through advanced surface engineering.

Researchers at IMDEA Materials Institute have demonstrated the successful additive manufacturing of two magnesium alloys through selective laser melting (SLM), while significantly improving their corrosion resistance through advanced plasma electrolytic oxidation (PEO) coatings.

The work, carried out as part of the Marie Skłodowska-Curie Actions MACS (Novel Magnesium Alloy for Bone Tissue Engineering Manufactured by Selective Laser Melting) project, establishes a complete processing route combining powder production, additive manufacturing and surface engineering for these promising alloy systems.

By successfully combining ultrasonic atomisation, SLM and PEO, the work expands the toolbox available to researchers and engineers working with high-performance magnesium alloys.

Lightweight, biocompatible and biodegradable, magnesium has attracted considerable interest as a potential material for temporary biomedical implants in recent years. However, its wider adoption has been limited by difficulties associated with manufacturing and controlling its corrosion behaviour.

The MACS project addressed these challenges by combining powder production, additive manufacturing and surface engineering technologies into a single development strategy.

One of the project’s first objectives was the production of spherical powders from two magnesium alloys, Mg-4Zn-0.5Mn and Mg-4Zn-0.5Ca. To achieve this, the researchers employed ultrasonic atomisation, a process capable of producing powders with the morphology and quality required for additive manufacturing.

These powders were then successfully processed using SLM, demonstrating that both alloy systems can be manufactured using already established metal additive manufacturing technologies.

“Atomisation and selective laser melting of magnesium alloys were crucial steps in this project,” says Dr. Mahdi Sabbaghian, lead researcher on the project. “Successfully producing powders and demonstrating their processability by SLM laid the foundation for all subsequent work.”

The achievement is particularly noteworthy because magnesium can be challenging to process due to its high reactivity and the demanding conditions associated with laser-based manufacturing techniques.

A second major focus of the project was improving the corrosion resistance of the alloys. While magnesium’s biodegradability is attractive for biomedical applications, excessive corrosion rates can compromise material performance.

To address this issue, Dr. Sabbaghian introduced PEO, a surface treatment technique that creates protective ceramic-like coatings on metallic components.

“The development of new electrolyte formulations and systematically optimised coating parameters, including voltage and current conditions, was key to these results,” he confirms. “The project required extensive experimental testing to identify processing conditions capable of producing robust and effective coatings.”

The resulting PEO treatments significantly enhanced the corrosion resistance of both magnesium alloys. For components manufactured by selective laser melting, the improvements reached approximately two orders of magnitude compared with uncoated materials.

These results demonstrate how carefully designed surface engineering strategies can substantially improve the performance of additively manufactured magnesium alloys.

The project also provided a unique opportunity to directly compare the behaviour of Mg-4Zn-0.5Mn and Mg-4Zn-0.5Ca alloys throughout the manufacturing chain, from powder production and additive manufacturing to surface treatment and corrosion testing.

This marked the first time these two alloy systems have been systematically compared as candidates for biodegradable implant applications while also demonstrating their manufacturability through selective laser melting.

Alongside Dr. Sabbaghian, the project brought together researchers from IMDEA Materials Institute in Spain, including Scientific Director Prof. Javier LLorca, as well as from the Warsaw University of Technology in Poland. Powder atomisation was carried out by AMAZEMET in Poland.

Funded by the European Union under Grant Agreement 101105323. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or European Research Executive Agency (REA). Neither the European Union nor the granting authority can be held responsible for them.