Distortion modelling of steel 316l symmetric base plate for additive manufacturing process and experimental calibration

Distortion in additively manufactured metal parts is of interest to keep structural reliability. It is important to control the dimensional tolerance of the additively manufactured structure. This does not only reduce the cost of manufacturing, but also improves the quality of the manufactured parts. Distortion in additive manufacturing (AM) is inevitable due to localized heating, large thermal gradient, thermal cycles, cooling rate, process parameters, etc. Base plate distortion during the AM process was studied in detail. Base plate structural deformation was measured using a 3D scanner. The surface geometry of the base plate reveals a large distortion beneath the deposited material due to the temperature gradient. Thermal history and distortion during the AM process were classified into three stages. Mitigation methods for the respective stage was discussed. A Finite Element Model (FEM) was built and a numerical calculation for thermal and distortion was validated to experimental results.