High-performance alloys for the additive manufacturing of energy converters

To date, only a few commercial alloys are available for the additive manufacturing of electric motor components. To make electric machines even more powerful in the future, new materials are needed that are specifically tailored to their requirements.

Under the leadership of Prof. Dr Dagmar Goll, the Institute for Materials Research (IMFAA) at Aalen University is relying on a new ‘rePowder’ ultrasonic atomisation system from Amazemet. Funded as part of a major equipment project, the system forms the basis for the development of bespoke high-performance alloys – for example, for energy converters, energy storage systems and hard metals. “The system provides an excellent basis for genuine material innovations: we can now develop completely new, very high-quality materials from pure elements or master alloys – particularly in small quantities for alloy development aimed at highly specialised applications,” reports Prof. Dr Dagmar Goll.
The process combines precision and efficiency: metallic material is melted using plasma or induction, then fed onto an ultrasonic sonotrode. The vibrations atomise the liquid metal into droplets, which solidify into spherical powder as they cool. Depending on the ultrasonic frequency, particle sizes ranging from 30 to 100 micrometres are possible – ideal for 3D printing. “The spherical shape is crucial for uniform flow and precise processing,” explains Felix Trauter, a PhD student at the IMFAA. “It enables us to produce alloys with precisely defined properties that are not available commercially anywhere else.”
The facility’s induction and plasma melting capabilities enable the processing of virtually any material. With a maximum temperature of around 3,000°C, almost any material can be processed, ranging from aluminium through highly reactive special alloys to tungsten. Even exotic materials such as lunar dust are possible. “For our research into energy storage systems, electric motors and generators, we need materials with very specific magnetic or mechanical properties. Until now, we had to make do with the next-best materials available – now we can develop them ourselves,” says Dr Thomas Kresse, a researcher at the IMFAA.
The system also enables direct recycling in line with the ‘cradle-to-cradle’ principle: at the end of its life, material can be directly converted back into high-quality raw material for additive manufacturing. “Support structures from the printing process are turned back into reusable powder – without any loss of quality,” explains Trauter. The material is recycled for the specialised application for which it was originally produced. This enables rapid iteration cycles in material development whilst making efficient use of resources.
Source: Aalen University