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
Quick, Precise, but not Cold
17.05.2017 | Fraunhofer-Institut für Lasertechnik ILT
A laser for divers
03.05.2017 | Laser Zentrum Hannover e.V.
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, the Italian Space Agency (ASI), and the Instituto Geofisico--Escuela Politecnica Nacional (IGEPN) of Ecuador, showed an increasing volcanic danger on Cotopaxi in Ecuador using a powerful technique known as Interferometric Synthetic Aperture Radar (InSAR).
The Andes region in which Cotopaxi volcano is located is known to contain some of the world's most serious volcanic hazard. A mid- to large-size eruption has...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
16.08.2017 | Physics and Astronomy
16.08.2017 | Materials Sciences
16.08.2017 | Interdisciplinary Research