Cutting-edge research in additive manufacturing strengthens Europe's space industry

AM research can streamline production of components for Europe’s rocket engines, including Ariane 6. Photo: Ariane Group

“There is great potential to save material, time, and money by using powder bed-based additive manufacturing (AM) for components for hydrogen-fueled rocket engines. But more knowledge is needed for the process to meet the high demands,” says Thomas Hansson.

Hydrogen is a common fuel for space rockets. It is also well known that metals exposed to hydrogen risk becoming brittle – a challenge that must be addressed when designing and dimensioning rocket engines. The nickel-based superalloy Inconel 718 is frequently used in the traditional manufacturing of components for hydrogen-powered rocket engines, as the industry has learned how to manage the alloy’s sensitivity to hydrogen embrittlement.

New insights on hydrogen embrittlement

“However, to produce components more efficiently using powder bed-based AM, we need to develop new knowledge about the phenomenon of hydrogen embrittlement,” Thomas explains.

“The components are exposed to extreme temperatures, loads and pressures in harsh hydrogen environments. We need to design the process so that the risk of cracks and other defects caused by embrittlement in the superalloy Inconel 718 is eliminated when using AM processes.”

Overview presented at Rymdforum

At Rymdforum, researchers from University West will present an overview of how AM can be used in space applications and how hydrogen fuel affects metals like the superalloy Inconel 718. The audience will also learn more about ongoing research projects being conducted by the university’s PhD students and senior researchers.

Thomas has been involved in research on hydrogen’s effect on metallic materials for 30 years. Through a joint position at GKN Aerospace and University West, he now supervises and coordinates the work of two doctoral students.

Developing test methods

“Robert Sundström is an industrial PhD student at Swerim, developing testing methods for metallic materials, focusing on Inconel 718 produced by powder bed-based AM. He is testing and evaluating a range of mechanical testing methods in close collaboration with Swerim and GKN Aerospace.”

In parallel, PhD student Karthik Vaidyalingam Arumugam is working to understand and evaluate how the mechanical properties of AM-manufactured Inconel 718 are affected by hydrogen, and how the alloy can be improved by adjusting process parameters.

Exploring heat treatment methods

“Karthik is also investigating how the metal’s properties can be enhanced through novel heat treatment methods. Heat treatment can change the microstructure of the superalloy. To understand the full picture, Karthik greatly benefits from the ongoing tests within the project. The collaboration between Robert and Karthik is crucial.”

GKN Aerospace is already conducting tests with AM-produced components for rocket engines as part of the European Ariane program.
"If the research achieves our goals, the company plans to launch the first powder bed-AM produced component made of Inconel 718 alloy as early as 2027."

FACTS

The manufacturing industry's interest in metal additive manufacturing is strong. Here are a few reasons why:
• Components can be produced with less material usage, at lower cost, and with higher functionality than with conventional manufacturing methods.
• For small series and components with complex geometries, powder bed-based AM is a competitive alternative to today’s traditional manufacturing techniques. Manufacturers can reduce development time, make rapid design changes, and decrease the number of parts by integrating multiple functionalities into a single component.

Contact:

Thomas Hansson, researcher at University West and Engineering Method Specialist in Material & Data Testing at GKN Aerospace.

At University West, we conduct research in collaboration with society to create a better future.