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Additively manufactured (AM) components in many cases require post-processing by machining operations in order to attain required surface finishes or tolerances and to remove support structures. These post-processing processes, often milling, pose significant challenges to the tool with regard to vibration and interrupted cuts which can lead to high tool wear rates. The tool wear may occur as a result of specific microstructural and mechanical characteristics of the AM components. Recent research shows that metal AM parts show higher strength compared to cast parts. In addition, Kim et al. report on anisotropy in AM parts. The requirements for machining AM components are thus complex and require a profound understanding of the component properties and machinability to allow for reliable and sustainable post-processing of metal AM components. IN the context of this work, AM parts manufactured with SLM (Selective Laser Melting) and WAMM (Wire Arc Additive Manufacturing) processes are analyzed with regard to microstructure and mechanical characteristics using nickel-based alloys, high strength steel, and titanium alloys as representative sample materials that are difficult to cut. Anisotropy and hardness gradients were stated for all AM parts analyzed. In this comparative study regarding cast and AM components the influence of such anisotropic material behavior on the tool wear, component surface quality, and the process stability in milling processes are analyzed. |
