Qualification of Direct Diode Lasers for Laser Beam Welding in Order to Enhance Process Efficiency

Abstract:

Laser beam welding has become an established joining technique in automotive manufacturing. Common solid-state lasers generate high-quality joints, but they provide low energy efficiency. By contrast, direct diode lasers (DDL) have superior energy efficiency, are cheaper to purchase and additionally require less utility space. To examine the overall performance of direct diode lasers in comparison to disk lasers, welding quality and energy consumption of the two lasers have to be evaluated. Additionally, for this contribution the stability of the DDL’s beam, like temporal variation of focus position and beam shape, is examined. It is found that a focus shift takes place for longer periods of emission, but the variation of the focus diameter in the initial focal plane is negligible. As expected, the direct diode laser consumes less energy than the disk laser for the same output power. Welding experiments are conducted using four different steel alloys that are exemplary for engineering materials used in automotive manufacturing. Metallographic analysis shows that weld seam depths and widths are on average larger using the disk laser. However even with the need for higher output powers to achieve equal seam geometries the DDL consumes less energy and thereby causes less costs.

• Periodical: Applied Mechanics and Materials (Volume 882)
• Pages: 127-134
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.882.127
• Online since: July 2018
• Authors: Kerstin Schaumberger*, Michael Mödl, Vincent Mann, Stephan Roth, Michael Schmidt
• Keywords: Automotive, Cost Saving, Direct Diode Laser, Energy Consumption, Laser Beam Welding

References

[1] D. Devarasiddappa, Automotive Applications of Welding Technology – A Study, International Journal Of Modern Engineering Research, 9:13-19, (2014).

[2] A. Heß, Vorteile und Herausforderungen beim Laserstrahlschweißen mit Strahlquellen höchster Fokussierbarkeit, Dissertation, Universität Stuttgart, (2012).

[3] M. Graudenz, M. Heitmanek, Laser tools in the manufacturing process – joining technology trends in body manufacturing at AUDI, Laser Technik Journal, 4:24-27, (2012).

DOI: 10.1002/latj.201290049

[4] S. Heinemann, H. Fritsche, B. Kruschke, T. Schmidt, W. Gries, Compact high brightness diode laser emitting 500 W from a 100 µm fiber, Proc. SPIE, 86052, (2013).

DOI: 10.1117/12.2003299

[5] F. Bachmann, Industrial applications of high power diode lasers in materials processing, Applied Surface Science, 208-209:125-136, (2003).

DOI: 10.1016/s0169-4332(02)01349-1

[6] A. H. Fritz, G. Schulze, Fertigungstechnik, 8th ed., Springer, Berlin, (2008).

[7] G. C. Rodrigues, h. Vanhove, J. R. Duflou, Direct diode lasers for industrial laser cutting: a performance comparison with conventional fiber and CO2 technologies, Physics Procedia, 56: 901-908, (2014).

DOI: 10.1016/j.phpro.2014.08.109

[8] Information on http://www.salzgitter-flachstahl.de, Stand 06.04.(2018).

[9] Information on http://www.trumpf.com/de_DE/produkte/laser/, Stand 28.02.(2018).