Numerical studies of residual states and scaling effects in laser-directed energy deposition additive manufacturing

Sequentially coupled thermo-mechanical model was used to simulate the residual stresses and residual distortions in the directed energy deposition additive manufacturing by laser. The proposed models were validated by comparison with experimental data. Different sizes of components were used to study the scaling effects. Results indicate that the residual stress can be controlled by the component sizes. This phenomenon can be explained by the bending deformation and the temperature fluctuations, especially the cooling rate, in the directed energy deposition additive manufacturing process. Both the bending deformation and the temperature fluctuations can be controlled by the ambient temperature and the designed process parameters. Analytical model was established to show how the components’ sizes affect the final residual states in combination with different design parameters.