Linde collaborates with Ariane Group on combustion chambers for Ariane Rockets

Linde and Ariane Group are collaborating in a research project to help improve the additive manufacturing process of copper alloy parts to be used in engine combustion chambers of future heavy-lift rockets. The general hope is that implementing AM processes more effectively will help reduce costs on the largely overbudget and much delayed Ariane 6 program for future vectors.

With the advancement of additive manufacturing, copper powder can now be used to develop engine components with highly specialized geometries (such as cooling channels), which were previously impossible using traditional manufacturing methods. While a superior heat conductor and recognized as a vital material for the aerospace industry, copper faces challenges in relation to the additive manufacturing process due to its reflective properties. The copper acts like a mirror to the laser so that a considerable amount of power is reflected and not used to melt the metal. A higher laser intensity is therefore needed, but this can risk overheating of the part and oxidation issues.

Using its bespoke gas mixture ADDvance Laser230, along with its unique oxygen control system, ADDvance O2 precision, Linde is collaborating with Ariane to test a highly precise additive manufacturing process to deliver consistent, high-quality printed copper components.

“Linde is very proud to be collaborating with Ariane on this project to improve the additive manufacturing process,” said Pierre Forêt, Associate Director, Additive Manufacturing, Linde. “Cooperating with world-leading partners like Ariane is at the core of our innovation culture.”

ADDvance Laser230 has been developed specifically to optimize printing outcomes in the laser powder bed fusion (LPBF) processes. With its proprietary blend of argon and helium, it helps mitigate fumes and spatter formation and accelerate cycle times, making the printing process more reliable and lowering the cost per part. It is alloy agnostic and ideal for additive manufacturing of complex or lattice-type structures.

The addition of ADDvance O2 precision in the printing process will ensure that a maximum oxygen level as low as 10 ppm will only remain in the print chamber. This extremely low residual oxygen level ensures that overheating and oxidation is mitigated, enabling more efficient printing, without the need to wait for layers to cool down. It also has the added benefit that non-oxidized powder can be reused, reducing material costs.

“To ensure the competitiveness of future launcher engines, improved additive manufacturing processes are a key factor, enabling reduced manufacturing costs and improved lead times while maintaining the non-negotiable quality and reliability that has made Ariane an industry leader,” said Mathias Palm, Process Specialist, Ariane Group. “We are confident that Linde’s gas expertise will contribute to optimizing the additive manufacturing process.”