Surface Segregation in Binary Solid Solutions: Theγ*−σ*Representation

On the basis of the specific surface energy ratio ${\gamma }^{*}$ and atomic-size ratio ${\sigma }^{*}$ of the two solid-solution constituents, it is shown that dilute substitutional alloys map into regions of the ${\gamma }^{*}-{\sigma }^{*}$ plane with common surface-segregation behavior, the mapping being different for the various surface-segregation theories. A comparison of theory with experiment is made for 45 bimetallic alloys, and general conclusions concerning the validity of the different theories and future directions are made.