Laser processes under development for hybrid component production
System technology with the rotating workpiece for ultrasonic-assisted laser beam welding process.
The Laser Zentrum Hannover (LZH) is currently developing two laser-based processes for the production of load-adapted hybrid solid components.
Hybrid semi-finished components are designed to save material and costs in production by only using expensive materials exactly where they are required on the part – for example, sections that need to be particularly wear-resistant.
The new laser processes will form part of a novel process chain under development in Hannover Germany, at the Collaborative Research Center SFB 1153 "Process chain for the production of hybrid high-performance components through tailored forming".
In addition to the LZH, the work is being undertaken by researchers from the Faculty of Mechanical Engineering at Leibniz University Hannover and the Institute for Integrated Production Hannover.
Ultrasonic-assisted laser beam welding
The first of the two new laser processes is being developed by the LZH’s Joining and Cutting of Metals group, who have succeeded in producing crack-free formable semi-finished products using ultrasonic-assisted laser beam welding.
The scientists have welded shafts made of various mixed compounds such as steel-steel or steel-nickel and developed corresponding processes. They have been exploring how cracks can be avoided and which parameters in the welding process influence quality characteristics such as weld penetration depth or weld reinforcement.
Hybrid semi-finished product for bevel gears with a high-strength coating in the area of the tooth flanks
The group now wants to ensure greater process stability by modulating the laser power, among other things, and to develop process control to achieve repeatable, reliable quality in producing semi-finished products. In addition, mechanical stresses in the component are to be reduced using ultrasonic post-treatment.
Laser deposition welding
The second new process is being developed by the LZH’s Machines and Controls group, who are conducting research into novel components with local, load-adapted property profiles.
To this end, the scientists have used laser hot-wire deposition welding to apply a cost-intensive, high-strength material as a coating specifically to areas of the component that are subjected to high loads during operation. Exemplary applications are tooth flanks of gear wheels. In this way, high-quality and hard coatings could be applied, and the properties of the coating were specifically influenced by the material selection.
In the next step, the group would like to develop process monitoring for quality assurance in deposition welding. For this purpose, the secondary radiation generated in the welding process is to be measured with special sensor technology and analysed with machine learning methods to be able to derive a prediction of the coating properties. The goal: non-destructive quality control of the coatings in the process.