Surface properties of Bi–Pb liquid alloys

The present work represents an experimentally based investigation of the applicability of a statistical mechanical theory in conjunction with a compound formation model (CFM) to describe surface properties of Bi–Pb liquid alloys. The surface tension of molten Pb, Bi and Bi–Pb alloys has been measured by the sessile-drop method over a temperature range. The results obtained show general agreement with other reported measurements on pure elements and their alloys as well as with calculated surface tension values. Based on the phase diagram evidence about the existence of the ε-Pb3Bi intermetallic compound, the phenomenon of compound formation in Bi–Pb liquid alloys has been analysed through the study of surface properties (surface tension and surface composition) and microscopic functions (concentration fluctuations in the long-wavelength limit and chemical short-range order parameter) in the frame of CFM.