An optimal method to calculate the viscosity of simple liquid ternary alloys from the measured binary data

An optimal method to calculate the viscosity of simple liquid ternary alloys from the measured binary data is investigated in this paper. In order to find a relationship which describes the ternary viscosity data from binary data most adequately, a comparison was made between three different approaches tested on the example of the Au–Ag–Cu system. The optimal method turned out to be the extension of the Redlich–Kister polynomial to excess viscosity without any ternary term. This optimal method was applied further on the Fe–Ni–Co system. The estimation of viscosities for liquid Fe–Ni–Co alloys was done in different sections with molar ratio of two components equal to 1:1, 1:3 and 3:1. A diagram showing iso-viscosity lines was constructed at the investigated temperature of 1873 K.