Picture: Chalmers University of Technology
Gas turbines are among the most thermally and mechanically stressed machines in energy technology. With the transition to hydrogen-based fuels, the demands on temperature resistance and long-term stability continue to increase. Additive manufacturing processes are seen as a potential key to precisely realizing complex geometries such as internal cooling channels. At the same time, it is becoming apparent that high-strength nickel-based superalloys in particular pose major challenges for 3D printing.
At the Chalmers University of Technology, doctoral candidate Ahmed Fardan Jabir Hussain is investigating the additive processing of the superalloy CM247LC. The material is already used in turbines in conventionally cast form, but is considered difficult to handle in powder bed fusion processes. During printing and especially during subsequent heat treatments, cracking occurs, and the creep resistance of printed components remains below that of cast parts.
“The superalloy is often called “the Holy Grail” of metal additive manufacturing. If we can process it successfully, it could enable higher operating temperatures and improve efficiency of industrial gas turbines,” says Ahmed Fardan Jabir Hussain.“One of the biggest lessons through this work is that you can’t just fix one problem in isolation. If you reduce micro-cracking too much, you might worsen macro-cracking or creep performance. A holistic approach is essential. That’s where collaboration with industry really helps.”
Hussain deliberately refrained from changing the alloy composition and instead focused on process optimization. By adjusting laser power, scan strategy, and heat treatment, he was able to significantly reduce crack susceptibility and improve high-temperature performance. In simple geometries such as cubes, nearly crack-free samples could be produced, while complex structures remain critical. His results also demonstrate ways in which creep behavior can be influenced through targeted process control.
“Fardan’s research has given us valuable insights into how to process these challenging materials. We’re already applying the learnings to develop new alloys and improve our additive manufacturing processes,” says Håkan Brodin.“We’ve reached the limits with traditional materials and cooling strategies. To go further, we need better materials and processes, and this research helps us do exactly that,” says Håkan Brodin.
The work was accompanied by close collaboration with Siemens Energy. Materials expert Håkan Brodin emphasizes that the insights gained are already feeding into the development of new materials and manufacturing strategies. According to Brodin, traditional materials and cooling concepts are increasingly reaching their limits.
“Even if this material in particular remains difficult, the lessons we’ve learned can definitely be applied to other superalloys and help advance additive manufacturing as a whole,” says Ahmed Fardan Jabir Hussain.
Even though CM247LC remains demanding, Hussain sees broader value in his research. The principles derived can be applied to other superalloys and contribute to gradually making metal 3D printing industrially viable for high-temperature applications.
Subscribe to our Newsletter
3DPresso is a weekly newsletter that links to the most exciting global stories from the 3D printing and additive manufacturing industry.
