Wire-based friction stir additive manufacturing

Additive manufacturing for metallic components has gained wide acceptance in diverse industries for low-carbon productions. The inherent solidification defects of melting-based additive manufacturing technologies are still to be solved. Here, wire-based friction stir additive manufacturing (W-FSAM) was proposed, which can realize the solid-state manufacturing of large metallic structures via continuous feeding of wire materials. The main W-FSAM tools include a storage chamber with a wire feeding port, a screwed transport structure, and three stirring probes. The screwed transport structure was utilized to convey and extrude the feeding wires continuously. The stirring probes were used to accelerate the dynamic fluidity of the thermo-plasticized materials and improve the metallurgical bonding of the adjacent layers. Large structures without kissing bond induced by interfacial alternations were directly manufactured via W-FSAM without kissing bonds induced by interfacial alternations. Microstructures in the deposited layers were characterized as uniform, fine and equiaxed grains. This solid-state additive manufacturing strategy was evaluated to achieve 111% of wire base metal in terms of ultimate tensile strength. The W-FSAM technique shows the potential for fabricating large structures with high efficiency and performance.