Copper’s reflective properties make it challenging for traditional additive manufacturing (AM) techniques, with the material acting like a mirror to the laser, meaning large portions of power are reflected and not used to melt the metal. While a higher laser intensity can be used, this can risk oxidation issues as well as overheating the part. Recent advances in AM mean that copper powders can now be used to create complex geometries, such as bespoke cooling channels in rocket engine chambers.
The technique that Ariane and Linde are collaborating on uses Linde’s ADDvance Laser230 gas mixture. Developed specifically to optimise printing outcomes in laser powder bed fusion (LPBF) processes, it incorporates a proprietary blend of argon and helium, helping to mitigate fumes and spatter formation, as well as accelerate cycle times. According to the partners, it will enable them to create high quality printed copper components, including combustion chambers for the Ariane launchers of the future.
“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,” said Mathias Palm, process specialist, Ariane Group. “We are confident that Linde’s gas expertise will contribute to optimising the additive manufacturing process.”
According to Linde, the addition of ADDvance O2 precision will ensure that a maximum oxygen level as low as 10ppm will remain in the print chamber. This extremely low residual oxygen level means that overheating and oxidation is mitigated, enabling more efficient printing, without the need to wait for layers to cool down. Non-oxidized powder can also be reused, reducing material costs.
“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.”