Ad-Proc-Add researchers investigate influences on wire arc Additive Manufacturing
As part of the international Ad-Proc-Add project, a team from KU Leuven, Thomas More University, the Belgian Welding Institute npo, and Sirris, investigated the influence of various processes within the additive-subtractive manufacturing process chain on the quality of the final product. Empirical models for predicting bead geometry were created for both processes.
Wire Arc Additive Manufacturing (WAAM) is a Directed Energy Deposition (DED) Additive Manufacturing technique that uses an electric arc as a fusion source to melt filler wire and build a component layer by layer. The process enables the efficient production of medium to large metal parts, but after deposition, it exhibits low dimensional accuracy and surface quality, which is why further subtractive post-processing is often required.
A key aspect of the project was determining the material to be provided for machining to achieve the required dimensional and shape accuracy of the part. It was found that the WAAM process parameters significantly influence the effective wall width, the surface quality after deposition, and the minimum amount of material that needs to be removed during the post-processing step.
Another important finding related to the positioning, orientation, and optimal cutting parameters of the parts for post-processing. Experiments showed that the process parameters, especially speed, wire feed, and interpass temperature, had a significant influence on the characteristics of the deposited surface and the overall wall width that impact the milling process. Significant progress was said to be enabled by the development of multi-sensor platforms, which were used separately for the AM and post-processing steps, to investigate the influence of different processes on the properties of the final part. By monitoring current, voltage, gas flow rate, and temperature, the stability of the WAAM process could be evaluated, thereby eliminating various material defects and improving surface performance.
The insights gained were applied to various industrial case study parts on gas-based wire arc Additive Manufacturing and the additive-subtractive process chain and are now said to be part of several educational courses at KU Leuven and Thomas More. These advances demonstrate the enormous potential of WAAM technology and how it can be used to improve efficiency and quality in Additive Manufacturing.
The project’s final report can be obtained by contacting Forschungskuratorium Maschinenbau ([email protected]).
