Multi-Principal Element Alloys (MPEAs) are the subject of emerging interest due to their mechanical/thermal stability and strength at high temperature. A clear challenge is harnessing MPEA composition and microstructure to realize the potential oxidation and corrosion resistance. A unique aspect of MPEAs that has not been systematically explored is that MPEAs are thought to contain short-range order most simply as a variation in nearest neighbor configuration. This results in lattice distortions due to differences in atomic radii, as well as clustering effects, which are known to affect passivity in amorphous metallic glasses. Do variations in local structure give rise to non-uniform passivation and unpredictable corrosion behavior?

• Team: Johns Hopkins (lead), Northwestern, UVA, ASU
• Collaborators: Australian National U., U. Paris-Est/CNRS (Paris Creteil), ATI (Allegheny Technologies), Citrine Informatics, SLAC/Stanford, Columbia/Brookhaven National Lab, NIST
• Goal: Design, test, and produce high entropy alloys that are lightweight but withstand oxidation and corrosion by understanding atomic scale mechanisms in the base metal and associated oxides in concert and using that knowledge to screen for and design based on desirable properties on both sides of this complex interplay.