The German team developed a laser connection process for lightweight building structures

Modern lightweight structures are known to help the automotive, shipping, rail and aerospace industries save fuel and materials, thereby reducing their impact on the environment. Lightweight panels can also be made faster and cheaper than traditional methods.

Recently, Germany's Fraunhofer Institute for Materials and Beam Technology (Fraunhofer IWS) announced the development of a method to transfer this proven design principle to other industries.

Using a laser bonding process, they welded the thin filament cavity structure together with the cover sheet to form a lightweight "sandwich" sandwich plate. This metal structure can be produced particularly efficiently in the roll-to-roll process of the Fraunhofer IWS. New technology ensures higher production rates and a wider range of uses for lightweight panels, which opens up new lightweight construction perspectives for the construction of ship superstructures, railways and factory buildings.

(Photo credit: Fraunhofer IWS)

The laser-based 'sandwich plating' method offers much technical, economic and ecological potential for industry. "With this technology, lightweight panels and profiles can be produced much more quickly and cost-effectively than traditional methods," said Andrea Berger, Fraunhofer IWS researcher. In addition, the new process eliminates the need for adhesives and other additional materials, which facilitates easy recycling of lightweight structures produced with this process."

Today, many lightweight builders often use hollow sandwich plates instead of heavy steel plate centimeters thick. Although they are much lighter than solid steel, they are strong enough for vehicles, aircraft or lobby partitions or ceilings. Building manufacturers typically weld or bond sheets on the sides of thin steel, aluminum, or plastic internal structural frames.

A challenge to Fraunhofer IWS from a large van manufacturing company in Saxony, Germany, has launched a new laser rolling process: the manufacturer already uses lightweight aluminum profiles in its vehicle technology.

However, the extruding process they applied was difficult to accommodate internal sheets of any thickness, with a minimum thickness of about 1.5 mm. But because people want to save as much material and weight as possible, this becomes a puzzle.

Faced with this difficulty, the researchers at Fraunhofer IWS solved the problem with a laser welding mill. Using this system, they guided the flexible core layer of the lightweight internal structure between two rollers, with the covering plate rolling on top and bottom. The scanner-controlled laser is directed diagonally and precisely from both sides into the ultra-thin gap between the core layer and the surface.

(Photo credit: Fraunhofer IWS)