Process zone morphology and melt dynamics in laser remote fusion cutting (RFC) revealed by high-speed X-ray imaging

Burger S, Forster C, Spurk C, Hummel M, Olowinsky A, Beckmann F, Moosmann J, Schmidt M (2024)

Publication Type: Journal article

Publication year: 2024

Journal

Optics and Lasers in Engineering Elsevier

Article Number: 108756

DOI: 10.1016/j.optlaseng.2024.108756

Abstract

Laser material processing procedures yield numerous benefits, as non-contact manipulation of the workpiece, high precision, and extensive automation capabilities. For metal joining, laser beam welding is a widely used process employed in industry, for example in automotive body construction and in the production of electronic components. With the same optical setups as usually used for laser beam welding, a melt ejection can be induced in sheet metal, resulting in the formation of a cut. This enables laser remote fusion cutting (RFC) based on a melt ejection without the need for tools near the process zone. A comprehensive understanding of the conditions and mechanisms causing the melt ejection or preventing it is yet to be achieved. In this study, in-situ observations of the process zone in RFC were performed using high-speed X-ray imaging with synchrotron radiation, achieving frame rates up to [Figure presented] for steel samples and [Figure presented] for AlMg3 samples. Key features of the process zone morphology are extracted by means of image processing from the recordings, such as the angle of front wall inclination or the ejection direction for different process parameters. The front wall angle for RFC is in line with an established model for the front wall angle in laser beam welding. Propagation-based phase-contrast imaging reveals the melt film at the cutting front, showing a decrease of the melt film thickness with increasing feed velocities. Melt dynamics at transitions between process states of cutting and not cutting could be observed. The temporal resolution was insufficient to capture humps in the melt film at the front wall in steel samples. These were resolved for AlMg3 samples, confirming that humps at the front wall play an important role in the melt dynamics.

Authors with CRIS profile

Silvana Burger Lehrstuhl für Photonische Technologien (LPT) Carola Forster Lehrstuhl für Photonische Technologien (LPT) Michael Schmidt Lehrstuhl für Photonische Technologien (LPT)

Additional Organisation(s)

Erlangen Graduate School in Advanced Optical Technologies (SAOT)

Involved external institutions

Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen DE Germany (DE) Fraunhofer-Institut für Lasertechnik (ILT) DE Germany (DE) Helmholtz-Zentrum Hereon DE Germany (DE)

How to cite

APA:

Burger, S., Forster, C., Spurk, C., Hummel, M., Olowinsky, A., Beckmann, F.,... Schmidt, M. (2024). Process zone morphology and melt dynamics in laser remote fusion cutting (RFC) revealed by high-speed X-ray imaging. Optics and Lasers in Engineering. https://doi.org/10.1016/j.optlaseng.2024.108756

MLA:

Burger, Silvana, et al. "Process zone morphology and melt dynamics in laser remote fusion cutting (RFC) revealed by high-speed X-ray imaging." Optics and Lasers in Engineering (2024).

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