Advanced trim-cut technique to visualize melt flow dynamics inside laser cutting kerfs
Loading...
Date
2017
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Laser Applications
Abstract
Instabilities of the laser cutting front cause loss of quality due to the formation of striations on the
cut flank. The mechanisms of striation generation during laser cutting are still not yet fully
understood. To visualize the laser cutting process, the trim-cut technique was invented many years
ago and is being continuously improved by different authors in the last years as well as in current
studies. During a trim-cut, the laser beam is moved in-parallel along an existing sheet flank and
cuts off a stripe of less than a standard kerf width. The cutting front and the transition to the resultant
cut flank are directly visible. Without additional measures, the cutting gas jet expands during
trimming in the half space freed by the lack of a second cutting edge. To maintain a guided supersonic
gas jet path along the melt film and simultaneously enable the in-situ-observation of the
cutting kerf with high-speed imaging, the missing cut flank is simulated by a transparent substrate,
e.g., made of synthetic fused silica. In this manner, the gas jet is guided between the transparent
substrate and the opposite real cutting flank. In this paper, a comprehensive review about trim-cut
studies from different authors is given. Furthermore, an automated trim-cut test bench with two
fast, highly accurate x/y-tables and versatile control features, as well as recent research results on
melt flow characteristics during laser cutting of 6mm thick stainless steel with 1 lm wavelength
and nitrogen assist gas, are presented.
Description
Keywords
Laser cutting, High-speed imaging, Micron laser, Process diagnostics
Citation
Arntz, D., Petring, D., Jansen, U., & Poprawe, R. (2017). Advanced trim-cut technique to visualize melt flow dynamics inside laser cutting kerfs. Journal of Laser Applications, 29(2), 022213. http://dx.doi.org/10.2351/1.4983261