Modeling and Process Planning Tool for Hybrid Metal Additive/Subtractive Manufacturing to Control Residual Stress and Reduce Distortion

Hybrid Metal additive manufacturing (AM) is difficult. Residual stresses from directed energy deposition (DED) and laser powder bed fusion (LPBF) processes can be very information-dense. Infill patterns can greatly affect the residual stress distribution, and thus deformation, in the finished component. Subtractive manufacturing (SM) processes, such as milling, upset the balance of long-range residual stresses, as well as introduce new stresses at the cut surface. The majority of the academic work studying residual stresses from metal AM and machining processes is expository. They explain what the residual stresses are but lack an actionable plan to fix the issue. The key innovation proposed here is a framework by which the complex stress states produced by hybrid AM/SM processes can be addressed by two-stage optimization created with a unified set of simulation and computer-aided manufacturing (CAM) tools.