Overview and details of the sessions of this conference. Please select a date or location to show only sessions at that day or location. Please select a single session for detailed view (with abstracts and downloads if available).
Please note that all times are shown in the time zone of the conference. The current conference time is: 4th Aug 2021, 12:34:31am CEST
Session Chair: Dr. Klaus Schricker, Technische Universität Ilmenau, Germany
Location:Room 1 ICM
2:45pm - 3:00pm
Beam shaping with free-form optics for optimal material processing
Ulrike Fuchs1, Henrike Wilms1, Stephan Gräf2
1asphericon GmbH, Germany; 2Otto Schott Institute of Materials Research (OSIM), FSU Jena, Germany
The number of applications in material processing, where the focal intensity distributions should deviate from the Gaussian shape, is rapidly increasing. Of particular interest are not only top-hat or donut distributions, but also non-rotationally symmetric distributions such as squares or ellipses. We present refractive freeform beam shaping elements to generate such focal distributions. Moreover, these elements can generate patterns in the focal region with 3x3 or 4x4 spots. Here, the absolute size of all focal distributions is scalable with the NA of the used focusing lens.
Simulation results will be compared with measured intensity profiles to show good agreement. Furthermore, first experiments on stainless steel will show the different effect of the different intensity distributions on the material interaction. Since the refractive beam shaping elements used are also low dispersion, this opens new possibilities for material processing with ultrashort laser pulses.
3:00pm - 3:15pm
Cleaving tailored edges and curved surfaces of transparent materials by ultrafast lasers through advanced beam shaping concepts
Daniel Flamm, Jonas Kleiner, Myriam Kaiser, Felix Zimmermann, Daniel Grossmann, Max Kahmann
TRUMPF Laser- und Systemtechnik GmbH, Germany
Concepts for laser cleaving transparent materials trough volume modifications and mechanical, thermal or chemical separation gained increasing recognition for a broad bandwidth of industrial use by ultrafast lasers and application specific adapted optics. The deterministic energy deposition into the working volume is achieved by advanced spatio-temporal beam shaping. With these concepts single-pass, full-thickness modifications with m/s-feed rates were demonstrated for plane substrates with complex inner and outer contours and thicknesses of up to >10 mm at the same time with low edge roughness, low chipping and high edge stability.
These developed processing strategies lead to an increased demand for customized glass edges, including chamfer as well as bevel structures. This enables a reduction of potential edge fractures, an increased edge stability as well as the capability of e. g. curved surfaces. The efficacy of our concepts is presented by evaluating surface and edge qualities of different separated glass structures.
3:15pm - 3:30pm
Simulations on beam shaping in LPBF processes
Pareekshith Allu1, Frieder Semler2
1Flow Science Inc., United States of America; 2Flow Science Deutschland GmbH, Germany
To enable wider adoption, LPBF processes require manufacturing features with varying levels of detail at high production speeds. This becomes challenging when working with single mode lasers that operate exclusively in either the Gaussian or top hat modes. By varying spot sizes and beam shapes, new laser technologies can switch real time between different heat flux distributions that enable faster builds with higher detail.
In this presentation we discuss how CFD models built in FLOW-3D AMare used to analyze different heat flux distributions for single mode and ring beam modes that affect the melt pool dynamics. Gaussian distributions have higher localized temperatures resulting in high rates of vaporization compared to ring beam modes that distribute heat fluxes evenly over a larger area. Such CFD models also help generate process windows that utilize higher scan speeds for the various ring beam modes, ensuring higher productivity rates while maintaining process stability.