Microstructure-Deformation Relationship of Additive Friction Stir-Deposition Al-Mg-Si

Abstract This research provides the first description of the process parameter relationship to the microstructure/nanostructure and mechanical properties of Aluminum Alloy 6061 AFS-D deposits. The solid-state, additive friction stir-deposition, process provides a new path for coating, joining, and additively manufacturing materials with high deposition rates (20–30 lb/hour) while avoiding liquid-solid phase transformation defects. As-deposited samples revealed the AFS-D process reduced the average grain size by an order of magnitude over a range of processing conditions. Transmission Electron Microscopy (TEM) and Atom Probe Tomography (APT) analysis established β″ precipitates were dissolved by the AFS-D process and re-precipitated as Mg–Si solute clusters.