Shorter process steps, faster production times, short-term changes, lower material consumption, increased functionality and therefore reduced costs - the Fraunhofer Institute for Microstructure of Materials and Systems IMWS lists these properties of additive manufacturing and also announces a new research project. Together with the copper semi-finished product manufacturer KME, the use of additive manufacturing technologies for highly thermally conductive components is to be researched in a new project. Copper is a material with a very high thermal conductivity that is only surpassed by silver. As silver is only used as a material for individual special cases due to its high price, the project partners in the joint project "Technology and material development for the additive manufacturing of complex, highly thermally conductive copper components - CuAdd" are focusing on copper and its alloys. Research into additive manufacturing methods with copper is a market with future prospects.

Copper in additive manufacturing

The project evaluates additive manufacturing processes for metallic components, including fused deposition modeling (FDM), binder jetting (BJ), nano particle jetting (NPJ) and laser powder bed fusion (LPBF). With these technologies, the components are generated layer by layer. The copper grades Cu-ETP, Cu-OFE and Cu-HCP and the copper alloys CuCrZr and CuNi2SiCr are used as starting materials. They are tested and the compatibility of different polymer systems such as PLA (polylactic acids) and PA (polyamides) with copper systems is tested at the same time. Differences in further processing exist in the process-dependent material feed and the processing temperature.

Laser powder bed fusion favored method

The researchers' preferred method is laser powder bed fusion (LPBF): here, the material is applied in powder form in a thin layer on a base plate. The powdered material is completely melted in a defined manner using laser radiation at temperatures above 1000 °C and forms a solid layer of material. The plate is then lowered and powder is applied again. This cycle is repeated until all layers have been melted and the component is finished.

The project also examines which powder or powder mixture is suitable for which application in terms of its components. Factors such as particle size, flowability and porosity play an important role if the desired properties such as high thermal conductivity or high electrical conductivity of the components are to be achieved. As a result, the researchers want to use additive manufacturing processes to produce a prototype with a geometrically complex structure that can be used as a high-performance heat sink, for example.

According to documents from the Fraunhofer IMWS