<p>This study examines the effect that variations in heat input during the additive friction stir deposition (AFSD) process have on the mechanical properties, microstructure, and nanostructure of aluminum alloy 7050 (AA7050). Three AFSD builds were constructed using three different parameter sets, each of which caused a different operating temperature for the deposition when the tool face is in contact with the substrate. Additionally, large AFSD depositions undergo a new thermal cycle for every layer added, so the effect of this subsequent heating was also examined. Monotonic tensile testing was used to quantify the strength of each of the builds produced under different operating temperatures, as well as to compare the strength of locations within a given build that experienced different amounts of subsequent heating. Electron backscatter diffraction (EBSD), transmission electron microscopy (TEM), and energy-dispersive x-ray spectroscopy (EDS) were used for micro- and nanostructural analysis to connect changes in tensile behavior with micro- and nanostructure changes in the material. The results showed a statistically insignificant change in the microstructure of the as-deposited material. However, the TEM images displayed distinct changes in the nanoscale precipitate size in regions experiencing different deposition parameters as well as in regions within the same build that experienced a different number of thermal cycles. These changes in precipitate size correspond to the variations in strength observed during the monotonic tensile testing.</p>