Journal Published Online: 03 June 2019
Volume 8, Issue 6

New Welding Joint Geometries Manufactured by Powder Bed Fusion from 316L



In metal additive manufacturing, an increasing demand for large size parts occurs. However, because of the economics of size, the manufacturing costs for parts do not increase linearly with their volumes. It is often economically unreasonable to directly produce large size components. Instead of directly building parts, technologies like hybrid building are used. To avoid extensive clamping devices for welding, additive manufacturing can be used to design new gap geometries. With these new geometries, the positions of the parts can be defined and the deformations that are due to thermal influences by the welding process can be reduced. Nevertheless, the powder bed fusion process leads to a different microstructure that needs to be taken into account for the welding process. The new microstructure leads to an extensive shrinkage during welding that exceeds the shrinkage of conventionally produced parts. To avoid the shrinkage, the weld gap design not only has to fulfill the requirements of conventional welding but it also needs to avoid the shrinkage of the parts. The resulting shrinkage of the parts is, in one way, a disadvantage, but it can also be used as an advantage for subsequent laser welding processes. If additively manufactured parts should be laser welded to get a smooth weld surface, normally post-processing must be performed to fulfill the necessary gap distance. This can be avoided by combining different welding processes. If the backside of a part is first welded by conventional welding, the resulting shrinkage will close the gap on the structured surface. If laser welding is then applied to a structured surface, it is nearly impossible to see the weld. This article will present new designs for welding joints and show how the different welding behavior can be used to improve the additively manufactured parts for hybrid welding processes.

Author Information

Schwarz, Alexander
Department of Mechanical Engineering and Mechatronics, Institute for Toolless Fabrication, Aachen University of Applied Sciences, Aachen, Germany
Gebhardt, Andreas
Department of Mechanical Engineering and Mechatronics, Advanced Fabrication Technology and Additive Manufacturing, Aachen University of Applied Sciences, Aachen, Germany
Schleser, Markus
Department of Mechanical Engineering and Mechatronics, Joining and Laser Technology, Aachen University of Applied Sciences, Aachen, Germany
Popoola, Patricia
Department of Chemical, Metallurgical, and Materials Engineering, Advanced Engineering Materials and Surface Technologies, Tshwane University of Technology, Pretoria, South Africa
Pages: 16
Price: $25.00
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Stock #: MPC20180096
ISSN: 2379-1365
DOI: 10.1520/MPC20180096