This study aims to understand how alloying elements in the 7xxx Al alloy system impact its long-term corrosion performance for the optimization of cold spray repair processes. 7xxx Al alloys are widely used in the defense and aerospace industries because of their desirable strength-to-weight ratio. However, due to severe operating environments, 7xxx Al components are prone to corrosion and wear damage during service, requiring repair. Additive manufacturing (AM) processes may be used to repair damaged components, but not all AM techniques are viable for Al alloys because of solidification cracking. Cold spray (CS) is a fully solid-state repair process which may be feasible for to repair such components without the disassembly of complex systems. During the CS process, a powder feedstock is accelerated to high velocities using high-pressure gases at elevated temperatures to metallurgically bond to a substrate. Because high plastic deformation induced during CS, microstructures and corrosion properties are vastly different from conventional wrought products. In this work, 6 different 7xxx Al alloys were CS and characterized microstructurally via scanning electron microscopy (SEM), optical microscopy (OM), and energy dispersive x-ray spectroscopy (EDS); characterized electrochemically using polarization and rotating disk electrode (RDE); and characterized via immersion and GMW-14872 exposure testing. It can be shown that the presence of Cu and of minor alloying elements accelerates cathodic reactions within 7xxx Al alloys. Cu is also shown to raise corrosion potential, while minor alloying elements influence localized damage morphologies.
