Achieving great things with small particles: A researcher at the University of Wuppertal is developing new sustainable copper-based materials for 3D printing.
"In the NanoSTeW project, we are looking for a new material composition that is as strong and conductive as possible in order to use it for the production of components in additive manufacturing, i.e. 3D printing. Specifically, we are focussing on copper and addressing a problem that arises with its alloys," says group leader Dr Silja-Katharina Rittinghaus, explaining the project. And that's what's behind it: Copper plays a crucial role in various industrial applications, but also in our everyday lives. For example, it protects electronic devices against overheating: the metal has a high conductivity, so that any heat generated during operation is quickly dissipated by the copper. Although pure copper, which can also be processed as a metallic powder in 3D printers, is the most conductive, it is also a relatively soft material. In order to fulfil the highest technical requirements, the material used must be stronger. This is achieved using copper alloys, i.e. compounds with other metals. The problem is that all previously known materials are no longer as conductive as pure copper, meaning that the parts made from them do not utilise the full potential of their cooling capacity. The search is therefore on for new alloys that score highly in terms of thermal conductivity and strength.
Composite powder made of copper, silver and yttrium oxide
The NanoSTeW project is focussing on tiny parts: nanoparticles of silver and yttrium oxide. In combination with other elements, silver increases the strength of the metallic compound without negatively affecting its conductivity. Yttrium oxide ensures that the material becomes stronger even at high temperatures – again without impairing its conductivity. What’s new is the simultaneous combination of both materials with copper. "We have set ourselves the task," summarises Rittinghaus, "of combining copper, silver and yttrium oxide in the best possible way, developing new composite powders for 3D printing and, at the same time, testing them for two applications." Together with her project mentors, Rittinghaus wants to use the newly developed material to produce parts for a drive component for the aerospace industry and to coat a ceramic cooler with copper for thermal management in electronic devices and components. In future, the cooler could be used in the field of electromobility, for example in battery management systems, where it helps to control the temperature.
Bringing recycling into focus
As an additional component, the research group is focussing on the recycling process. The aim is to make the entire production of the new material mixture as resource-efficient as possible – at various levels. "For our powder, we are firstly looking to use copper extracted as a secondary raw material from other products. In our project, for example, this is copper from discarded solar panels," explains Rittinghaus. Secondly, the researchers are considering the question of how the copper from the production trials can be recycled if it does not yet have the desired properties.
Throughout the various project steps, the project brings together scientists with expertise from very different fields: materials science, materials engineering, chemistry and nanotechnology, as well as from physics, process engineering and computer science. The project is also supported by mentors from industry. Researcher Rittinghaus is also receiving around two million euros from the Federal Ministry of Education and Research to set up a new junior research group at the University of Wuppertal.
Source: idw/ University of Wuppertal
