Spot melting sequences for complex geometries in electron beam powder bed fusion

Kupfer T, Leimbach S, Spano L, Pohl S, Körner C, Markl M (2025)

Publication Type: Journal article

Publication year: 2025

Journal

DOI: 10.1007/s40964-025-01251-w

Abstract

Abstract: Spot melting in electron beam powder bed fusion is a current research focus. This method exploits the ability of the electron beam to jump almost instantaneously between individual spots. This leads to an immense freedom in scan strategy design compared to line melting and opens up a wide range of unexplored strategies for robust processing of defect-free parts with tailored material properties. However, each layer of a part consists of thousands of spots ending up in an almost infinite number of possibilities to order them in a spot melting sequence. Common state-of-the-art approaches like random melting or pattern melting create a geometry independent, fixed spot sequence, thus do not use spot melting to its full potential. Planning a geometry-dependent spot sequence needs efficient algorithms due to the immense number of possibilities. In this work, we extend our graph-based, heuristic algorithm, which determines spot melting sequences on independent groups. The original approach is prone to failure, if the geometry contains areas far apart from each other or if areas are only connected via filigree regions. The proposed extension adds a subdivision of groups into communities thus taking advantage of the divide-and-conquer principle. The communities are ordered in a sequence by the approximate solution of the corresponding traveling salesman problem. With those additions, it is possible to determine suitable spot melting sequences for arbitrary geometries as long as the total number of spots per layer is high enough. We compare the algorithm with common spot melting strategies using a complex brake caliper geometry. Finally, experimental results including electron optical images and corresponding temperature simulations are presented. Graphic abstract: (Figure presented.)

Authors with CRIS profile

Involved external institutions

pro-beam AG & Co. KGaA / pro-beam additive GmbH Germany (DE)

How to cite

APA:

Kupfer, T., Leimbach, S., Spano, L., Pohl, S., Körner, C., & Markl, M. (2025). Spot melting sequences for complex geometries in electron beam powder bed fusion. Progress in Additive Manufacturing. https://doi.org/10.1007/s40964-025-01251-w

MLA:

Kupfer, Tobias, et al. "Spot melting sequences for complex geometries in electron beam powder bed fusion." Progress in Additive Manufacturing (2025).

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