Surface Tension Measurements of Liquid Iron-Nickel-Sulphur Ternary System Using the Electromagnetic Oscillating Droplet Technique.

Abstract

Surface tensions of liquid iron-nickel-sulphur ternary alloys as a function of the composition and the temperature have been determined by the oscillating droplet method combined with electromagnetic levitation technique. The natural frequency of the oscillating droplet was evaluated using a Fourier analyzer, and the influence of magnetic field strength on the surfac tension was also considered. The temperature dependence of surface tension for the liquid iron and iron-nickel melts containing the surface active element sulphur were found to be positive. This effect may be due to the change of the sign in the entropy terms for the bulk and surface phase caused by the reduced mobility of the surface atoms. Furthermore, iso-surface tension diagram for the iron-nickel-sulphur ternary system at 1873 K is given and discussed.