The excess surface tension of regular binary liquid alloys
Iván Egry and Jürgen Brillo
Starting from Butlers equation, an explicit expression for the excess surface tension of a binary alloy is derived. First, the case of ideal solution is treated within the weak segregation limit. Then, interactions are included through the partial excess Gibbs enthalpies for regular solutions. The derived expressions allow the study of the interplay between surface segregation and the enthalpy of mixing. As a test case, the model is applied to liquid Cu-Ni yielding excellent agreement with the experimental data.
Keywords: Surface tension, Butler equation, Regular solution, Liquid alloys