Laser Zentrum Hannover develops underwater DED system for in-situ steel structural repairs. The Laser Zentrum Hannover (LZH), based in Germany, has initiated the RoLaKI project to develop a robot- and laser-based Directed Energy Deposition (DED) system capable of performing additive manufacturing repairs on steel structures directly underwater. The research focuses on integrating laser cladding technology with specialized robotic manipulators to restore structural integrity to maritime infrastructure without requiring dry-docking or component extraction. By utilizing localized shielding and specialized nozzle designs, the system aims to deposit filler materials such as 316L stainless steel in high-pressure, submerged environments.

This development addresses a critical maintenance bottleneck in the maritime and offshore energy sectors, where traditional repair methods like welding often require costly and time-consuming environmental isolation. While underwater welding is established, the precision of DED offers superior control over heat input and material properties, potentially reducing the heat-affected zone and improving the fatigue life of repaired steel components. The project positions LZH at the intersection of robotics and metal AM, competing with specialized underwater maintenance service providers that currently rely on manual or semi-automated arc welding processes. As offshore wind and maritime infrastructure age, the demand for automated, in-situ repair solutions is projected to grow, providing a clear value proposition for reducing operational downtime.

For industrial adoption, the primary challenge remains the qualification of underwater-deposited metal microstructures to meet stringent maritime safety standards. Stakeholders should focus on the project's ability to demonstrate consistent mechanical properties and bonding integrity across varying depths and water conditions. Successful validation of this DED process will require rigorous testing of the laser-material interaction under hydrostatic pressure to ensure the reliability of the deposited steel layers.