The production of large-format metal components with freeform surfaces and low quantities is typically achieved through shape milling from cast blocks. This is also the case for Arnold AG and the art objects they manufacture. The large structures are divided into subassemblies and then shaped into the appropriate form through milling. Subsequently, the components are manually polished. Often, thin-walled components are produced, some of which have a machining volume of approximately 95%. Additionally, the required cast blocks have a lead time of about 9-12 months, making flexible production challenging in addition to the high material costs. The high machining volume and the resulting waste are a significant cost factor. To reduce material usage, this project aimed to develop and implement a suitable process chain, focusing on the additive manufacturing of large-format art objects. Using the additive manufacturing method Direct Energy Deposition – Arc (DED-ARC), which involves gas metal arc welding, components will be produced, and the influence of the welding process on subsequent steps such as machining and polishing were investigated.

The use of demonstrator components, each with varying levels of difficulty, led to a significant reduction in machining volume and the number of required parts. Nevertheless, challenges arose when combining different build strategies or geometries. Due to very high standards for polishing streaks were revealed in the final polishing step. Through extensive investigations, the remelted layer was identified as the cause. To mitigate this, different temperature regimes were tested, and the streak formation was reduced significantly.