Geometry based path planning for robust process design in DED-Arc

Directed Energy Deposition—Arc (DED-Arc) is promising for manufacturing large metallic structures due to its high deposition rates and process flexibility. However, variations in process conditions can cause deviations in layer geometry and contact tip-to-workpiece distance (CTWD), limiting geometric consistency. Conventional slicing approaches assume planar layers and predefined process parameters, restricting their application to complex geometries and adaptive manufacturing. This work presents a geometry-based path-planning strategy that uses 3D laser line triangulation (LLT) scans of each deposited layer to generate the subsequent deposition trajectory while maintaining the CTWD close to its nominal value. The approach enables layer geometry to be adapted directly to the deposited part without requiring predefined layer heights or geometry-specific preliminary experiments. Experiments investigate the influence of torch travelling speed and CTWD on wire feed rate and layer geometry and compare scan-based trajectory adaptation with two a priori strategies based on constant and travelling-speed-dependent layer heights. The results show that constant layer heights cause significant CTWD deviations and process termination for complex geometries. Speed-dependent layer-height adaptation improves near-net-shape capability but requires preliminary experiments. In contrast, scan-based trajectory adaptation prevents CTWD deviation without prior geometry-specific experiments. The results demonstrate the potential of integrating process data and part geometry for stable and geometrically consistent DED-Arc deposition.