Oerlikon, Linde and TUM embark on €1.7M project to develop aluminum alloy for AM

A team of influential players in the AM industry are coming together to develop a new high-strength and lightweight aluminum alloy for the aerospace and automotive industries. Materials expert Oerlikon will be working alongside industrial gases company Linde and the Technical University of Munich (TUM) to pioneer the new 3D printing metal, supported by €1.7 million in funding (50% of which is from the Bavarian Ministry of Economic Affairs).

Last month, within the context of MTC3, a Bavarian AM cluster between Oerlikon, Linde, TUM and GE Additive was established as a way to promote cross-disciplinary collaborations and research in the region.

In addition to that, Oerlikon, Linde and TUM have teamed up for a consortium in which each member brings to the table unique expertise and knowledge base. By pooling their resources, the three partners are committed to bringing a new high-strength aluminum alloy to market for AM. The development of an aluminum alloy for AM with optimal strength and weight will require a deep knowledge of fields like chemistry, thermo- and fluid dynamics.

Dr. Alper Evirgen, Metallurgist at Oerlikon AM, commented on what it will bring to the table, saying: “Using our proprietary software, which enables big data simulation and analysis, Scoperta- RAD, Oerlikon provides critical solutions for the development of new materials and performance optimization of available materials.”

There are a number of challenges in developing aluminum alloys for AM. For one, though the addition of magnesium helps to reduce the weight of the metal, it is challenging to 3D print because of its low boiling temperatures. This project will address these challenges in unique ways.

As Dr. Marcus Giglmaier, Project Manager at the AM Institute and Research Funding Manager, explained: “There are significant challenges during the additive manufacturing of aluminum alloys because the temperatures reached in the melt pool create an extreme environment that leads to evaporation losses of alloying elements that have comparatively low boiling temperatures – such as magnesium. Additionally, the cooling rates of more than 1 million °C per second, create high stresses during the solidification process, which can cause micro cracks in the solid material.”

Linde, an expert in gas atmosphere control and evaporation suppression in the AM process, will thus have an important role to play in the research collaboration. It will utilize its technology to ensure that the aluminum alloys do not succumb to impurities in the print chamber and result in high quality parts.

“Characterizing and controlling the gas process during AM not only has the potential to prevent evaporation losses, but also to accelerate the entire printing process,” said Thomas Ammann, Expert Additive Manufacturing at Linde. “Using a tailor-made gas chemistry for the new alloy would help to control the processes occurring in the melt pool and minimize the compositional changes of the alloys, as well as preventing cracking during printing.”

The third key part of the collaboration comes from the TUM Institute of Aerodynamics and Fluid Mechanics (AER), which will provide a detailed understanding of the physical phenomenon taking place in the AM process through numerical simulations. That is, AER has developed a process simulation tool that addresses melt pool dynamics from beginning to end (from solid, to liquid and then to gas). The tool also provides phase change models and data about surface-tension effects and thermal transport.

TUM’s Dr. Stefan Adami added: “A detailed insight into the simultaneously occurring thermo-fluid dynamic phenomena is crucial in gaining a better understanding of the entire process and the final material characteristics.”

Ultimately, the aluminum alloys for AM developed by Oerlikon, Linde and TUM could have applications in the aerospace and automotive industries, where strength and reduced weights are both critical material properties.