SolidStir Additive Manufacturing: A Novel Deformation-Based Additive Manufacturing Using Friction Stir Technology

Deformation-based solid-state additive manufacturing techniques are known for high build rates, absence of process-induced defects that are detrimental to mechanical performance, refined equiaxed microstructure, large-scale customization, and manufacturing at ambient conditions. We introduce a novel severe plastic deformation-based SolidStir((R)) additive manufacturing (Solid-Stir((R)) AM) technique here. The process utilizes frictional heating between a non-consumable rotating tool and a feedstock to soften and plasticize the material inside a process chamber at high temperature, which is subsequently deposited in a layer-by-layer fashion under the coupled action of compressive and shear forces. In this work, aluminum 6061-T6 was used as the feedstock material for feasibility study of SolidStir((R)) AM. The deposited material possessed a defect-free, refined, and wrought-like microstructure (similar to 11 mu m average grain size), enhanced ductility (similar to 160% improvement), and better corrosion resistance than the base material. Based on preliminary results, SolidStir((R)) AM appears to be a promising solid-state additive manufacturing tool that can be applied in many applications.