It is possible to weld thick pipelines and metal sheets made of aluminum alloys or steel at high speeds of 6 m/min. respectively 1.5 m/min. with a hybrid welding process developed at the Laser Zentrum Hannover e.V. (LZH). In the future, the laser-based process can be used to shorten processing times, and thus significantly reduce the processing costs of liquid gas tanks and pipelines
cientists of the Joining and Cutting of Metals Group at the LZH have developed a process that can be used to make single-sided, zero-defect welds for aluminum sheets up to a thickness of 12 mm. To do so, they have combined a laser beam with two gas metal arc welding (GMAW) torches. A scanner mirror can be used to oscillate the laser beam lengthwise or crosswise to the feed direction.
The laser-hybrid welding process combines the advantages of laser beam and GMAW welding.
In the future, the hybrid welding process developed at the LZH can reduce manufacturing costs for pipelines.
The joining process can reach feed speeds of 5 to 6 m/min, and gaps of up to 0.5 mm and edge misalignment of up to 2 mm can be bridged. The engineers have also been able to weld steel sheets with a thickness up to 23 mm at a speed of 1.5 m/mm for single layer welds.
Perfect welding seam
The innovative process is not only extremely fast: In comparison to conventional methods with multiple layer gas metal arc welding processes, the seam geometry is very narrow and filler material consumption is considerably lower. At the same time, the quality of the weld seam is very good: Welds for 12 mm thick metal sheets made of the aluminum alloy EN AW‑6082‑T6 could reach the highest evaluation group B for welding seam impurities according to DIN EN ISO 12932 and DIN EN ISO 13919‑2.
In comparison to conventional processes, a further advantage of the combined processes is reduced thermal input, and thus reduced component distortion. A solid-state disk laser with an output power of 16 kW is used for the hybrid welding process.
Twelve times faster than gas metal arc welding (GMAW)
In order to join steel sheets with a thickness of 30 mm, conventional gas metal arc welding requires a tack weld and around six filler layers. The hybrid process only needs two to three filler layers. The first layer is made using the laser-GMAW hybrid process. It also replaces the tack welds and the first four layers of the conventional gas metal arc weld. Subsequently the sheets are subject to one or two backing runs with the GMAW process. Thus, the hybrid welding process can be used to weld a component with a length of 1.5 meters in one minute, whereas conventional processes need twelve minutes.
Combining advantages and compensating disadvantages
The main advantages of hybrid welding are the synergy effects between the arc of the GMAW process and the laser beam. In the combined process, the laser is coupled into the melt pool of the filler material of the GMAW process: The filler material is melted by the arc and in the molten state it absorbs the energy of the laser beam and transfers the energy to the weld area between the sheets. The laser beam and the arc process stabilize each other, making relatively high welding speeds for arc processes possible and for high gap widths.
The joint project „HYBRILAS: Welding of thick metal sheets using brilliant laser beam sources“ was part of the „MABRILAS initiative: Material processing with brilliant laser beam sources” and was financially supported by the German Federal Ministry of Education and Research (BMBF), and supported by the Association of German Engineers (VDI-TZ).
http://www.lzh.de/en/publications/pressreleases/2014/welding-thick-metal-sheets-... Additional figure and video
Lena Bennefeld | Laser Zentrum Hannover e.V.
Intelligent wheelchairs, predictive prostheses
20.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA
Jelly with memory – predicting the leveling of com-mercial paints
15.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
22.03.2018 | Trade Fair News
22.03.2018 | Earth Sciences
22.03.2018 | Earth Sciences