CEPAM – Circular Economy Powder for Additive Manufacturing

Nowadays, it is important to examine the aspects of "sustainability", "CO₂-footprint" and "circular economy" from the ground up in newly developing, "disruptive" production processes such as additive manufacturing processes, and to anticipate future ecological and economic developments for these processes.

Additive manufacturing processes offer a variety of advantages, especially in product design, but they are complex with regards to consumption of resources, especially the metal powders, which is the required raw material for these processes. The powder properties are transformed more or less directly into the properties of the printed component, so the requirements for these powders are high: Ideally, they are spherical and pore-free, have no agglomerates or satellites and a low content of oxides or nitrides.

During the 3D printing process, the oxygen content of the powder increases, the number of agglomerates increases, while sphericity decreases. This means that the powders used in the printing process cannot be reused as often as desired; rather, they must be disposed after a certain number of printing processes, or they are sent to lower-quality processing processes. The more often a material can be used in 3D printing in the powder bed, the lower the overall footprint of the process chain will be. However, since this is not possible indefinitely, it makes sense to recycle the powder that has already been used and to feed it back into the high-quality additive manufacturing process in the sense of a circular process chain.

For realisation, the project is divided into 3 phases:

• In the first project phase, the various options for energy input to remelt the powder are evaluated in terms of energy efficiency, scalability and powder quality, and the respective opportunities and risks are worked out in small scale tests
• In the second phase, the most promising methods are set up in pilot scale and various metal powders are spheroidized. The powders "retreaded" in this way are then printed via laser powder bed fusion and the properties of the components are examined
• In the third stage, titanium alloy powder in particular is recycled and the surface oxides produced during the printing process are reduced. The powders are then printed and the properties of the components are again examined and compared with components made from "new" powder.

Project management

Anna Köll
Metalpine GmbH

Project partners

• Montanuniversität Leoben
  Chair of Process Technology and Industrial Environmental Protection
• Montanuniversität Leoben
  Chair of Metal Forming

Anna Köll
Metalpine GmbH
Kratkystraße 2, 8020 Graz
Tell.: +43 681 20755220
E-Mail: koell@metalpine.at
www.metalpine.at