| Abstract Scope |
Without material melting, additive friction stir deposition provides a deformation processing route to metal additive manufacturing, resulting in fully dense, ultrafine-grained alloys even in the as-printed state. The process involves downward material feeding combined with high-speed rotation, which results in complex 3D flow paths of individual voxels in the feedstock. Through tracer-based characterization and process modeling, the material flow patterns are readily controlled by the thermomechanical processing history. By carefully engineering the feed material, the complex material flow can be harnessed to print innovative heterostructured and mesostructured materials with 3D entangled domains, achieving structures unmatched by other processing or additive manufacturing methods. Coupling this with dynamic phase and microstructure evolution enables simultaneous control of structural features across multiple length scales, potentially resulting in intriguing bulk mechanical performance. This is demonstrated through additive friction stir deposition of feed material consisting of phases with similar elastic properties but drastically different plastic properties. |