A true-to-scale gas turbine is an impressive demonstration of the current potential and limitations of powder bed-based additive technologies. The turbine, manufactured using only additive processes, is in full working order.
Together with H+E-Produktentwicklung GmbH in Moritzburg, Saxony, the Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM) in Dresden has developed a scaled model of a gas turbine for power generation on a scale of 1:25. Except for the shaft, everything was manufactured using additive processes. The individual parts of the original, numbering nearly 3,000, were reduced to a component assembly of 68 parts made of aluminium, steel and titanium thanks to component optimisation and electron and laser beam melting. The turbine is in full working order. At the same time, the combination of conventional manufacturing technologies, in this case turning, and additive processes with laser beam melting (LBM) and selective electron beam melting (SEBM) is demonstrated in one component.
Production planning a crucial factor
The Fraunhofer IFAM was involved in the manufacturing of the component and the data modification for the technology-driven production. The housing components with stator blades were manufactured on site at the Innovation Center Additive Manufacturing (ICAM) in Dresden. They were produced from the material Ti-6Al-4V using electron beam melting (EBM) in the Arcam Q20+ plant. The turbine blades and the remaining housing components were made using laser beam melting at H+E. The production planning was extremely important and therefore very complex: the right technology had to be determined for each component. For example, surface precision and roughness had to be taken into consideration, as well as the necessity and number of supporting structures and the size of the components.
The component is an example of the combination of different materials that are commercially available from the plant manufacturers involved. Not all of the processed materials correspond to the target materials for turbines. A significant limitation is that these materials cannot currently be processed in a way that enables them to be offered commercially.