In this video you will find impressions around the AKL'18 as well as voices of some participants. Have a look and get to know us or review the three days in Aachen with over 660 participants!
Further information about the AKL can be found here:
On the occasion of the award ceremony for the Berthold Leibinger Innovationspreis on September 21, 2018, the Berthold Leibinger Stiftung presented an image film portraying the scientists Dr. Andres Gasser, Thomas Schopphoven and Gerhard Maria Backes. Also the Extreme High-Speed Laser Material Deposition (EHLA) process is presented in the video.
With its partner institutes active in various fields of lightweight production technology (750 scientists and 1,100 graduate assistants) on the RWTH Aachen Campus, AZL regroups all the required know-how to help the composites industry develop tomorrow’s lightweight production technology. The institutes’ knowledge covers the fields of textiles (ITA), plastics and composite materials (IKV), production technology (WZL, ISF, Fraunhofer IPT and Fraunhofer ILT), quality assurance and production-integrated measurement technology (WZL), lightweight design (SLA) and automotive production (IKA).
With the demonstrator the various applications of laser technology in the processing of plastics can be demonstrated:
All laser-based processes are characterized by a high degree of flexibility, an energy deposition that can be precisely adjusted in terms of location and time, and a high degree of automation.
Fibre-reinforced plastics (FRP), the use of which is becoming increasingly widespread due to their great lightweight construction potential, generate high tool wear during mechanical processing by milling or drilling, which is avoided by non-contact laser cutting. The cut 1 mm thick composite material is made of polypropylene, which is also reinforced with glass fibres.
The challenge in laser transmission welding of two optically identical plastic parts lies in the selective heating of the joining area in order to avoid component distortion and burns on the irradiated surface. As a rule, a highly focusing fixed optic is used for this, which, however, can only be guided over the component with contour accuracy up to a certain speed due to inertia. Scanners offer higher dynamics, however, with which the beam cannot be focused sufficiently strongly. This restriction can be overcome by irradiating the welding contour quasi-simultaneously and thus achieving selective heating of the joining area by heat accumulation.
Depending on the component thickness and the required quality (precision) and productivity (drilling time), holes with diameters from 1 µm up to several millimeters can be achieved by using single-pulse drilling, percussion drilling, trepanning or helical drilling. The single pulse drilling can be performed "on-the-fly", so that up to 300 holes per second with a diameter of e.g. 60 microns in 1 mm thick material can be achieved. Larger hole depths can be achieved by using percussion drilling. For hole diameters larger than 300 microns, trepanning is used where a relative movement between the workpiece and laser radiation occurs. Holes with high precision concerning geometry and high metallurgical quality are achieved by using helical drilling.
Approximately 74,000 holes with a diameter of 1.5 mm shall be drilled into the primary nozzle of a jet engine by using laser radiation. The drilling technique trepanning is used. The nozzle has a diameter of about 900 mm and a length of about 350 mm. The holes will be drilled distributed into 2048 rows, each with 36 holes around the circumference of the nozzle. The nozzle with a material thickness of 1.5 mm is made of titanium alloy Ti 6-2-4-2.
With pulsed CO2 laser radiation (Q-Switch), ZERODUR®, a glass ceramic material, can be precisely processed. The material removal in the example shown was realized with the following parameters:
Laser ablation and laser polishing of glass offers flexible and cost-effective alternatives to conventional manufacturing processes. Laser-based ablation processes can be used both for shaping and for shape correction polishing (Laser Beam Figuring).
Diameter of the machined geometry: 50 mm
When fused silica is processed with CO2 laser radiation, the laser radiation is absorbed in a thin surface layer of the workpiece so that the temperatures can be raised up to the material’s evaporation temperature. If the fused silica is heated locally by the interaction with the laser radiation above the evaporation temperature, material can be ablated. Pulsed CO2 laser radiation (Q-switch) with these parameters was used for the laser process shown in the video:
Sample size: 20 mm x 20 mm x 5 mm
With the laser process shown in the video an arrangement of defined lens geometries on fused silica was generated. The material was ablated with pulsed CO2 laser radiation (Q-switch) and these parameters:
Laser ablation offers the advantage of contactless processing. High costs for grinding tools are therefore avoided by an almost wear-free tool during laser ablation. Local ablation can generate not only free-form surfaces but also steep flanks for structuring the back of optics, for example to reduce weight.
Sample size: 90 mm x 90 mm x 4 mm
Components are protected against corrosion and wear through hard chrome plating, thermal spraying, laser material deposition or other deposition welding techniques. However, there are downsides to these processes – for example, as since September 2017, chromium(VI) coatings require authorization. Researchers from the Fraunhofer Institute for Laser Technology ILT in Aachen as well as the RWTH Aachen University have developed an ultra-high-speed laser material deposition process, known by its German acronym EHLA, to eliminate these drawbacks. EHLA does not contain the environmentally harmful chromium(VI). With the developed process, components can be coated, repaired or additively manufactured in a particularly economical and environmentally friendly manner.
Dr. Andres Gasser and Thomas Schopphoven from the Fraunhofer Institute for Laser Technology ILT in Aachen and their colleague Gerhard Backes from the Chair for Digital Additive Production of the RWTH Aachen University have developed the EHLA process and were therfore honored with the Joseph von Fraunhofer Prize 2017.
The Fraunhofer Institute for Laser Technology ILT has developed an offline programming system for laser material deposition. The LMD Cam3D program enables process developers and end‐users to generate tool paths quickly, even for complex LMD tasks that have non‐standard welding strategies. The generated paths are translated into machine code, and can be tested for possible collisions via a machine simulation. LMD Cam3D will be presented for the first time at the EuroMold from November 27 ‐ 30, 2012 in Frankfurt at the Fraunhofer joint booth, hall 11‐ C66a.
In this demonstration, laser cladding, also known as Laser Metal Deposition (LMD), is used to additively manufacture a three-dimensional part without support structures. Off-line programming is used to generate the program for the robot system at Fraunhofer ILT. Inconel 625, a nickel-based super-alloy, is used as additive material. This material is often used in the turbine and chemical sector. A continuous coaxial powder nozzle from Fraunhofer ILT is used. Total process time is 23 minutes. For further information please visit our website: http://www.ilt.fraunhofer.de/en/technology-focus/laser-material-processing/laser-metal-deposition.html#