Setting sail on lighter, stronger ships

Strong, lightweight materials are essential for reducing fuel consumption in shipbuilding. Combinations of high-strength steel with low-density aluminum alloys are ideal for this purpose, but joining these components requires careful arrangement. The explosive welded adapter, the current standard in shipbuilding, still falls short in cost, convenience, and weight.

To advance alternatives, Lahdo et al. explored laser beam welding for joining steel and aluminum.

“Laser beam welding is gaining increasing importance for the joining of thick-walled dissimilar joints with limited weldability, which is also reflected in the growing demand from users,” said author Rabi Lahdo. “We are pleased to see such developments in this field, but the journey is not over yet.”

A key focus of their work is to minimize the formation of disruptive intermetallic phases and microstructures as a result of welding this dissimilar joint. To do so, the authors positioned a steel sheet on top of an aluminum sheet, which has pre-machined grooves filled with iron-rich welding powder. Then, two intersecting laser beams simultaneously welded the dissimilar materials at an angle, enabling precise control over an undercut nestled in between, achieving a snug fit.

The authors used metallographic analysis and tensile tests to characterize how groove depth influences the metallurgical and mechanical properties of a joint. These parameters provide insight into creating a functional, durable weld. An extension to their laser beam welding approach is already in the works.

“In the next project, we plan to join these thick-walled dissimilar joints of steel and aluminum without the formation of irregularities,” said Lahdo.

Source: “High-power laser beam welding of adapters for joining steel and aluminum for thick-walled applications in shipbuilding,” by Rabi Lahdo, Oliver Seffer, Sarah Seffer, Jörg Hermsdorf, and Stefan Kaierle, Journal of Laser Applications (2025). The article can be accessed at https://doi.org/10.2351/7.0001926 .

This paper is part of the Proceedings of the International Congress of Applications of Lasers & Electro-Optics (ICALEO® 2025) Collection, learn more here .