Audi remote welding for A8 cars lowers cost by 90 per cent

Audi has implemented a remote laser welding process to join aluminium door panels on its A8 series that reduces the cost of processing by 90 per cent compared to traditional methods.

Dr Jan-Philipp Weberpals, responsible for technology development for joining in light construction in the laser beam and sensors division at Audi, gave an overview of the new process at a press conference for the Lasys trade fair, held at Audi’s production facility in Neckarsulm, Germany on 2 March.

The Neckarsulm plant manufactures Audi’s higher performance cars, including the A8 and R8 models, producing up to 190 vehicles each day.

Weberpals said that the cost savings came from the remote joining process – remote laser welding has the advantage of speed over tactile laser welding, as the beam is moved around using a scanning mirror rather than shifting the entire processing head or workpiece from weld to weld – as well as the elimination of filler material and inert gas.

The processing time from the start of the first seam to the end of seam nine is 11.56 seconds using remote laser welding, whereas the tactile process takes 24.79 seconds.

Remote welding also puts almost half the amount of energy into the part than tactile laser joining (33kJ/m for remote welding compared to 62kJ/m for tactile), which makes the weld less susceptible to hot cracking, according to Weberpals.

He said that welding thin sheets of aluminium used to be difficult because laser energy would cause cracks to form in the seam. The new remote procedure offers much more control over the laser beam in terms of heat management and positioning. The greater process control also means that no filler material is required or inert welding gas.

Audi has a patent pending on the process and is the first automotive manufacturer using this technology, Weberpals stated. The remote welding process has been developed together with laser equipment supplier Precitec.

The steel doors of the new Audi A3 are also joined with remote laser welding at the company’s Ingolstadt, Germany factory. The system uses disk lasers from Trumpf to produce lap joints. The 500 laser steps are made in 26 seconds, extremely quickly thanks to the remote processing.

Lasers are also used for surface treatment such as sidewall frames for the Audi Q7 prior to laser bean welding. The automaker’s CleanLaser process removes impurities, such as oils, lubricants and release agents picked up from the pressing plant, while leaving the base aluminium unaffected.

The cleaning process, using a pulsed laser scanned across the material, is a pre-treatment before the sidewall frames are joined with the roof and the water channel, and is a necessary step to give high quality joins.

The car manufacturer also uses lasers for brazing, typically with diode lasers, and for metrology, for measuring the dimension of components during the production process.

The laser material processing trade fair, Lasys, will showcase many of the technologies used by Audi when it is held from 31 May to 2 June in Stuttgart, Germany.

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