Abstract:

Thanks to their layer-by-layer working principle, additive manufacturing processes offer the potential to integrate previously unrealizable functions and geometries in metal components. For example, concealed cooling channels close to the contour can be realized in molds to ensure uniform temperature control within the molding process. Despite the flexibility of additive manufacturing, however, components generated in this way are not directly ready for use, but always require post-processing, usually in several stages, including the removal of support structures, the improvement of surface and geometric properties, and the setting of defined edge zone and material properties.

One approach to increasing efficiency is to combine additive and subtractive processes in a single machine or linked manufacturing cell, which is often referred to as "hybrid manufacturing." As a particular advantage, this approach enables sequential additive and subtractive manufacturing, so that functional elements that are not accessible later can still be reworked by machining during the build process and then covered again. This makes it possible, for example, to manufacture concealed cooling channels with flow-optimized surfaces.

To investigate this topic, a hybrid manufacturing cell for combined cold spraying and milling is currently being set up and put into operation at Leibniz-IWT. Compared to existing powder bed systems, cold spraying enables a very fast and large-volume material application, which is flexibly realized via a robot-guided spray gun and thus also allows the production of complex component geometries. Since the operating point of cold spraying is below the melting temperature of the powder material, the components produced in this way exhibit low thermal distortion. The system is complemented by a 5-axis milling machine for machining the components. A common clamping system allows components to be moved between the two parts of the system with reference to each other, so that any intermediate measuring steps for recording the component contour are avoided. In the future, the entire manufacturing process chain will be mapped in a digital twin so that the current assembly status and the essential material, surface and geometric properties can be tracked at any time in the sense of "material-oriented production".

The lecture in the context of the event series "Leibniz-IWT Live" introduces the concept of the hybrid manufacturing cell at Leibniz-IWT as well as its digital mapping and gives a first insight into experiments on the production and post-processing of steel substrates made of established alloys (316L) and newly developed alloys or powders (FeTiB, FeMnAlC) at Leibniz-IWT.