  Compositionally complex alloys hold the promise of simultaneously attaining
superior combinations of properties, such as corrosion resistance,
light-weighting, and strength. Achieving this goal is a challenge due in part
to a large number of possible compositions and structures in the vast alloy
design space. High-throughput methods offer a path forward, but a strong
connection between the synthesis of an alloy of a given composition and
structure with its properties has not been fully realized to date. Here, we
present the rapid identification of corrosion-resistant alloys based on
combinations of Al and Cr in a base Al-Co-Cr-Fe-Ni alloy. Previously unstudied
alloy stoichiometries were identified using a combination of high-throughput
experimental screening coupled with key metallurgical and electrochemical
corrosion tests, identifying alloys with excellent passivation behavior. The
alloy native oxide performance and its self-healing attributes were probed
using rapid tests in deaerated 0.1 mol/L H2SO4. Importantly, a correlation was
found between the electrochemical impedance modulus of the exposure-modified
air-formed film and self-healing rate of the CCAs. Multi-element extended x-ray
absorption fine structure analyses connected more ordered type chemical
short-range order in the Ni-Al 1st nearest-neighbor shell to poorer corrosion
resistance. This report underscores the utility of high throughput exploration
of compositionally complex alloys for the identification and rapid screening of
a vast stoichiometric space.
