For small and medium sized enterprises (SME) which use lasers to weld thin metal sheets, lasers with continuous wave radiation are often too expensive. This is due to the high output powers necessary for the welding process.
Pulsed Nd:YAG lasers are economically interesting, and offer an alternative to continuous wave lasers. Due to their high peak pulse output, welding with relatively low medium output power (100 w to 250 W) is possible, and investment costs can be reduced.
However, the narrower welding seams from the pulsed lasers not as strong as the seams from continuous lasers. Results can be improved if the parameter selection is optimized. This was the goal of a recently completed project at the Laser Zentrum Hannover e.V. (LZH).
The results of this project aim at simplifying the parameter selection for pulsed laser welding, for example pulse duration, pulse form or pulse peak output. Also, reference parameters for welding with continuous wave radiation have also been recorded. For both types of laser welding, high seams qualities could be qualified and weld imperfections avoided, as shown in surface testing and seam cross-sections. For the investigations, both ferritic and austenitic steels with sheets thicknesses up to 1.5 mm were butt joint welded.
Also, thin foils with a minimal thickness of 50 µm were butt-joint welded. To accomplish this, the LZH developed and constructed a high precision clamping unit, which not only assures a zero gap, but also avoids a lateral edge mismatch.
Especially SMEs can use the results of the welding tests, which are available in an electronic database on the LZH internet site (www.lzh.de). The database provides welding and laser parameters as well as pictures of the expected seams surfaces, cross-sections and micro-hardness tests. Firms can use this data to estimate welding results. Apart from simplifying the selection of appropriate parameters, users can easily expand the database themselves by adding parameters of their own welding tasks to the database and accessing them when needed.
The investigations were commissioned by the Research Association of the German Welding Society (DVS) and funded by the German Federation of Industrial Research Associations "Otto von Guericke" e.V. (AIF) in project 15.297N.Contact:
Michael Botts | idw
New manufacturing process for SiC power devices opens market to more competition
14.09.2017 | North Carolina State University
Quick, Precise, but not Cold
17.05.2017 | Fraunhofer-Institut für Lasertechnik ILT
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research