Deposition rate is the WAAM story
WAAM trades resolution for raw mass-deposition speed. A 200 kg ship-grade fitting that would take weeks on DED-powder finishes in a few days on a 3-axis WAAM cell. Combined with the 10–20× lower feedstock cost (welding wire vs gas-atomised powder), WAAM is usually the only economic answer above a few hundred kilograms.
Machining allowance is the WAAM cost
The trade-off is everything downstream of the deposition cell. A WAAM part needs 3–8 mm of stock on every machined face, the surface is wavy enough that adaptive machining strategies are recommended, and inspection has to handle the rougher datum surfaces. On a part dominated by machining cost rather than deposition cost, DED-powder usually beats WAAM despite the higher feedstock price.
Decision shortcut
If the part is > 50 kg, low-feature-count, and made of a weldable alloy, default to WAAM. If the part is < 20 kg, has machined features on most faces, or needs an alloy outside the welding-wire catalog, default to DED-powder.
Frequently asked questions
Can WAAM hit aerospace-grade allowables?
For ER70S-6 and 308L stainless, yes — there is established structural-welding precedent that translates. For Inconel 718 and Ti-6Al-4V, WAAM allowables are typically derived per-program rather than read from MMPDS because the public coupon base is still thin.
Sources
- Williams, S. W. et al. (2016). Wire + arc additive manufacturing. Mater. Sci. Tech. 32.
- AWS D20.1/D20.1M:2023, Specification for Fabrication of Metal Components using Additive Manufacturing.