FOCUS ON LASER WELDING
Laser Multi-Pass Narrow Gap Welding ( Laser MPNG )
Above and below : The cross-sections of a butt joint and a T-joint produced using laser MPNG show the seam quality that can be produced with significantly reduced costs and resource consumption . © Fraunhofer IWS .
the potential cost savings are even higher at up to 80 per cent ,” confirmed the Fraunhofer team .
“ The cost savings in terms of welding filler materials alone can amount to more than 100,000 euros per year for larger companies . In addition , the laser beam sources used offer great potential for stemming rising energy costs due to their high efficiency ( approximately 50 per cent ) and good process efficiency ( reduction of energy input by 80 percent ). With this evidence of practical suitability , the approach can now be extended to other applications ,” it continued .
Strong foundations
The Fraunhofer-Gesellschaft , based in Germany , is one of the world ’ s leading applied research organisations . Prioritising key futurerelevant technologies and commercialising its findings in business and industry , it plays a major role in the innovation process .
Founded in 1949 , the Fraunhofer- Gesellschaft currently operates 76 institutes and research units throughout Germany . Over 30,000 employees , predominantly scientists and engineers , work with an annual research budget of € 2.9 billion . Fraunhofer generates € 2.5 billion of this from contract research .
The non-profit Fraunhofer-Gesellschaft ’ s namesake is Munich scholar , Joseph von Fraunhofer ( 1787 – 1826 ). He enjoyed equal success as a researcher , inventor and entrepreneur .
The Fraunhofer Institute for Machine Tools and Forming Technology ( IWU ) is a driver for innovation in the research and development of production engineering . Around 670 employees at its facilities in Chemnitz ,
The laser is positioned at the joint between the two sheet edges to be welded , while a filler metal is added . The energy of the laser beam melts the edges of the workpieces , as well as the filler metal from the wire , which then fills the void between the two pieces and creates a high-quality weld seam . The process can be used to weld typical joint configurations in steel construction .
The sheet edges are plasma-cut and the joint sometimes has gaps of up to 2mm-wide , which the laser welding process can bridge . When welding either a web plate ( T-joint ) or a butt joint , the process ensures that the joint is complete i . e . that the two parts are joined across the entire contact area . In conventional steel construction , this is not always 100 per cent guaranteed due to the process involved . There are also technological limits , particularly when using T-joints .
Dresden , Leipzig , Wolfsburg and Zittau tap new potential for competitive manufacturing in automotive and mechanical engineering ; aerospace technology ; medical engineering ; electrical engineering and precision and micro engineering .
“ We focus on scientific developments and contract research concerning components , processes , methods and the associated complex machine systems – the entire factory ,” it told ISMR .
As a leading institute for resource-efficient production , it develops technologies and intelligent production systems for car body and powertrain components . It optimises the production stages of forming , cutting and joining processes taking into account the entire process chain and factoring in regenerative systems and the circular economy . Crucial success factors include the development of innovative lightweight structures and technologies for the processing of new materials , the transfer of functions into assembly units and last , but not least , the economic utilisation of fuel cell technologies . n
The cost savings in terms of welding filler materials alone can amount to more than 100,000 euros per year for larger companies
34 | sheetmetalplus . com | ISMR April 2022