The core of the WAAM process is the electric arc: an arc is generated between a continuously fed wire and the workpiece, reaching temperatures well above the melting point of the wire.

Unlike traditional welding, the molten metal doesn’t simply drip away. Instead, it is precisely deposited as a controlled melt pool onto the surface of the part. Because the surface of the previous layer is locally remelted, a high-quality metallurgical bond is formed between layers.

By moving the welding torch relative to the workpiece, the melt pool follows a programmed path. Once solidified, it forms a defined bead. Multiple beads placed side by side and layer by layer build up a fully three-dimensional component.

The feedstock used in WAAM is typically a qualified and standardized welding wire, similar to those used in conventional arc welding. Wire offers several key advantages: it is easy to store and transport, can be almost entirely incorporated into the final part, and achieves a material utilization rate of nearly 100%.

Welding wires are available in a wide range of alloys – from unalloyed steels and aluminum to titanium and nickel-based materials. At the same time, wire feeding is process-reliable and easy to control.

After the print with WAAM, post-processing may be required depending on the application – typically through milling, turning, or grinding. WAAM already produces high-quality, functional structures, but for tight tolerances – such as fits, sealing surfaces, or interfaces – subtractive machining ensures additional precision. Compared to fully milled components, WAAM offers a key advantage: material is only removed selectively and in reduced quantities.

In conventional machining, large amounts of expensive raw material are lost. In contrast, WAAM builds the part close to its final shape, allowing post-processing to refine only specific areas.