Empa researchers are studying 3D metal printing for the repair of installed steel components

(CONNECT) Researchers at Empa’s Engineering Structures division in Dübendorf aim to use 3D metal printing to repair and, in the future, redesign load-bearing steel components in structures. The focus is on the Wire Arc Additive Manufacturing (WAAM) process, in which metal is applied layer by layer to damaged areas, according to a press release.

In the WAAM process, a welding wire is applied layer by layer to the damaged area of a steel component using an electric arc. The key factor in the effectiveness of the repair is not the amount of material applied, but the geometry of the reinforcement. In a series of experiments, two-layer, stepped reinforcement structures proved to be particularly effective.

The advantage of the WAAM process is that damaged areas can be reinforced locally and effectively without having to replace the entire defective component. According to the statement, localised repairs are particularly important in the context of infrastructure projects such as bridges or structural frameworks, since the steel components installed there can hardly be replaced due to the constant load they bear.

Practical application remains a challenge: Damaged components are usually firmly integrated into the structure and would often have to be removed and transported to a workshop for repair. Although mobile robot systems are currently under development, further progress is needed before they can be widely used directly on construction sites.

In the long term, the researchers see further potential applications for the WAAM process. These include metallic damping elements for bridges, buildings, and technical facilities, as well as lightweight, heavy-duty components for mechanical engineering.

In addition, Empa is investigating the use of shape-memory alloys. These materials can return to their original shape after being deformed, and when combined with 3D metal printing, they open up new possibilities for adaptive and material-efficient metal components. ce/ja