Additive Manufacturing of Copper Alloys for Space Propulsion and Thermal Management (CufAM)

Copper and copper alloys are critical to space propulsion and thermal management systems due to their exceptional thermal conductivity. However, conventional manufacturing methods significantly limit achievable geometric complexity, constraining thermal efficiency and system integration.
Additive manufacturing (AM), particularly powder bed fusion (PBF), offers a transformational route to produce highly complex copper components for space applications. However, copper’s high reflectivity makes it difficult to process using conventional infrared laser PBF systems, introducing risks around density, defects and material performance.

Through the CufAM project, MTC and its partners advanced the end‑to‑end AM process chain for both GRCop-42 and pure copper, demonstrating credible AM routes for both rocket combustion hardware and advanced thermal management systems.
This project was a collaboration between the Manufacturing Technology Centre (MTC), Airborne Engineering (AEL), Fraunhofer-Institut für Lasertechnik (ILT) and Azimut Space GmBH (ASG), funded through the European Space Agency (ESA).

Project challenges

• Copper’s high reflectivity and thermal conductivity lead to unstable melt pools and high porosity in conventional infrared PBF‑LB.
• There is limited industrial experience with non‑infrared AM routes for copper alloys in space‑relevant components.
• There is also a lack of validated end‑to‑end AM process chains for copper, spanning powder handling, processing, post‑processing and inspection. Copper’s sensitivity to oxygen and moisture, as well as its ductility, makes this even more challenging.

MTC's solution

• The consortium selected two representative space materials/applications: a GRCop􀇦42 combustion chamber liner for liquid rocket propulsion, and pure copper phase change material (PCM) thermal devices.
• Green laser PBF routes were developed for these materials, tailored to each application.
• End􀇦to􀇦end AM process chains were developed, including powder characterisation and storage studies, process parameter development and validation and heat treatment optimisation.
• Demonstrator hardware was designed, manufactured and tested, including a 20 kN combustion chamber with AM copper liner and novel expansion slots, and PCM heat capacitors and heat.

The outcome

• Demonstrated green‑laser PBF‑LB as a viable route to manufacture high‑density (>99.9%) copper and copper alloy components for space
• Achieved functional GRCop‑42 combustion hardware capable of hot‑fire testing under representative operating conditions
• Developed heat treatment strategies enabling ~300 W/mK thermal conductivity while retaining sufficient mechanical strength in GRCop‑42
• Introduced novel AM expansion slots in rocket combustion chamber liners, enabling reduced thermal fatigue
• Demonstrated that AM copper lattice structures significantly improve thermal performance, showing up to 72% improvement in conductance and delivering 3–3.5× higher heat storage capacity than aluminium equivalents
• Generated validated data on powder handling, oxygen pickup and processing sensitivity to support future qualification routes

Benefits to the client

• Accelerates the readiness of copper AM process chains for future ESA programmes.
• Provides confidence in deploying AM copper alloys for propulsion and thermal‑management hardware.
• Demonstrates credible alternatives to existing manufacturing methods.
• Enables lighter, more thermally efficient components through AM‑enabled geometric complexity.
• Establishes a foundation for ECSS‑aligned qualification of copper AM components.