CAD/CAM Process Chain for Hybrid Additive Manufacturing

Abstract

Hybrid additive manufacturing (AM) by direct metal deposition (DMD) and milling combines the advantages of both additive and subtractive processes for part fabrication. While the additive process ensures a high level of design flexibility and material efficiency, the consecutive milling steps realize the final surface quality. However, the great engineering effort for hybrid AM processes currently limits their application in several industries. Time-consuming trial and error approaches need to be replaced by model-based manufacturing strategies throughout the entire production process. The present study focuses on a CAD/CAM process chain that includes machine characterization techniques and control of the heat input. Within the machine characterization, the alignment of the melt pool to the milling tool is investigated. To control the heat input of the AM process, the effectiveness of a geometry-based approach is tested. Finally, the entire process chain is evaluated by the fabrication of a demonstrator part. The results show that the integration of machine characterization and heat input control increases the robustness of the hybrid AM process. The proposed process chain may therefore lead to a reduction of engineering effort for industrial applications.