As an emerging non-beam-based technology, friction stir-facilitated deposition (or ‘Additive Friction Stir’) enables metal additive manufacturing through a solid-state thermo-mechanical process. In this process, the filler material is fed through a rotating tool and forced to flow and spread between the tool and substrate, undergoing severe plastic deformation and dynamic recrystallization. In contrast to friction stir welding, this process does not include joining of workpieces or use of a probe; instead, deposition is facilitated by the friction between the filler materials and substrate as well as the rotating tool. It differs significantly from the so-called ‘friction stir additive manufacturing’ process, which is based on sheet joining. In this talk, we will use a few examples of engineering alloys (e.g. Inconel, Steel, Ti-6Al-4V) to illustrate the advantages of this process, such as promoting microstructure refinement, enabling the manufacturing of traditionally unweldable materials, as well as preventing particle aggregation and mechanical anisotropy.