Additive Manufacturing Process and Dimensional Control

Direct metal laser sintering offers many advantages over traditional casting and forming processes because it can produce complex geometries using materials that cool rapidly due to their specific microstructure and properties. During printing, however, large temperature gradients can develop and cause distortions that render parts unusable for aerospace applications.After an extensive literature search and multilevel, multivariable design of experiments, Inconel 718, a high-temperature alloy powder, was chosen for the print prototype. Alloy selection, build orientation, support structures, layer thickness,and precompensation for distortion were considered in the design of experiments. The turbine blade produced was scanned using blue
light interferometry in order to compare the simulation’s predicted results with a physical print. Metallurgical analysis was performed to evaluate the material properties and microstructure achieved during the printing process. A strong correlation was found between the simulated distortion and the actual distortion of the printed part, indicating that dimensional control in additive manufacturing can be achieved using computer simulation and careful alloy selection.