Laser Welding Method Enables Lightweight Metal Structures

The Fraunhofer IWS researchers solved the dilemma with a laser welding rolling mill. To complete a cycle of the method, they guide a flexible core layer of light internal structures between two rollers, over which a cover sheet rolls at the top and bottom. Scanner-controlled lasers aim obliquely from both sides precisely into the thin gap between the core layer and the cover sheet. There, the metal surfaces are heated with pinpoint accuracy. Depending on the sheet material selected, local temperatures of between 660 and over 1400 ºC are generated. The rolls then press the slightly melted surfaces of core layer and cover together so firmly that they bond permanently.