Comparison of Surface Tension Measured Values for Molten Tin at Different Oxygen Potentials

The surface tension of molten tin has been determined by a set of a self-developed digital equipment with the sessile drop method at an oxygen partial pressure of 1.0×10−6 MPa at different temperatures. The dependence of surface tension of molten tin on temperature was discussed as well. Based on the summarized relationships of the surface tension of molten tin to temperature and oxygen partial pressure reported in the literature, the reasons for the differences in those reported data were analysed. The emphasis was placed on the comparison of surface tension of the same molten tin sample measured by using different equipments according to the sessile drop method. Results of the comparison indicate that the measurement results obtained with the sessile drop method under similar experimental conditions are coincident, and the self-developed digital equipment for surface tension measurement has a higher stability and accuracy. The relationships of surface tension of molten tin and its temperature coefficient with temperature and oxygen partial pressure were also elucidated from the thermodynamic analysis in this paper.