Thermomechanical Analysis and Optimization of Residual Stresses in SS۳۱۶L Components Fabricated by Directed Energy Deposition

The Directed Energy Deposition (DED) process is very sensitive to thermal environments, tends to produce residual stresses and geometric distortion. It is important to understand the influence of processing parameters on these effects in order to enhance build quality. The objective of this study is to control residual stress and distortion in the DED process by investigating baseplate thickness, number of layers deposited before laser interruption, dwell time, and laser power by a full factorial experiment design. The numerical results were validated by experimental measurement of residual stress using the X-ray diffraction (XRD) technique. The optimized processing conditions resulted in a ۴۳% reduction in residual stress and a ۳۳% decrease in dimensional distortion compared to the baseline setup. Among the four factors, baseplate thickness had the most significant effect, whereas dwell time had the least impact. To the best of the authors’ knowledge, the combined effect of baseplate thickness, dwell time, number of layers deposited before laser interruption, and laser power on residual stress and distortion in DED has not been previously investigated. The findings of this study provide a mathematical basis for future research aimed at optimizing process and material parameters in DED process.

کلیدواژه ها:

Direct Energy Deposition ، Residual Stress ، Thermal-Mechanical Modeling ، Optimization