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

Hybrid metal additive/subtractive manufacturing is an emerging technology that combines geometry flexibility of additive manufacturing (AM) and the good surface finish of subtractive manufacturing (SM). It has been shown that AM introduces tensile stress at part surface that triggers crack initiation. SM processes such as milling and turning can introduce compressive stress at surface, which counter-balances the tensile stress in AM, leading to less residual stress and distortion. Despite the attractive benefits, hybrid AM/SM is not yet matured because the large process parameter space. To expedite the process optimization, Global Engineering and Materials, Inc. (GEM) and collaborators propose to develop a full process chain modeling and planning tool to simulate the thermal- and mechanical-induced residual stress during the AM, SM, and the post-process heat treatment (HT) process. In Phase I, the research team will implement modularized models for AM, SM, and HT, and validate against the residual stress/strain measurement in each stage of the process chain. A detailed test plan will be developed to demonstrate the modeling capability over a range of process conditions based on simple geometries for controlling the distortions and internal residual stresses of as-built and post-processed parts.