Micro-milling and micro-EDM residual stresses evaluation on post-processed 3D printed samples

Micromachining is essential for producing microscopic components or obtaining complicated details in high-precision devices. Micromachining on 3D-printed metal samples is a cutting-edge, interdisciplinary field that blends additive manufacturing with accurate subtractive machining processes at the microscale. This method aims to precisely remove material from 3DPrinted metal items to obtain complicated geometries with strict tolerances, and high-end surface finishes. The surface integrity is not only determined by the surface roughness, but it depends also on the residual stresses caused by the thermo-mechanical loads during the Additive Manufacturing and the Micromachining processes. This paper aims to analyze the residual stresses measurements after Micromachining with both Micro-Milling and Micro-Electrical Discharge Machining of 3DPrinted metal samples. 17-4 PH stainless steel 3D printed samples were produced with Laser Powder Bed Fusion. The analysis of the residual stresses was carried out by producing microchannels of different sizes (200 μm and 800 μm) to also investigate the scale effect.