Surface Tension and Density of Indium-Tin Alloys

Abstract

The article presents the results of experimental studies on concentration and temperature dependence of surface tension (ST) and density of indium-tin alloys. The characteristic feature of these experiments is that we studied surface tension and density by two independent methods that improved reliability of data and allowed us to solve some problems. In particular, experimental data on ST received by both methods proved that SF concentration dependence has a shallow minimum, which exceeds the limits of experimental uncertainty, in the area of average compositions. With an increase in temperature, the extremum depth decreases and when temperature is higher 773 К the minimum almost vanishes. It proves that isotherms σ of ideal solutions can be characterized by these minimums if pure components (indium and tin in this case) have similar values of physic-chemical properties. The experiments showed that within temperature ranges from the melting point to 773 К the surface tension and density of pure metals (indium and tin) and binarybased alloys are linearly dependent on temperature. Experimental data on density received by two methods (aerometric and a big drop method) evidence that alloys density values coincide with additive values within experimental uncertainty. Curves show concentration dependence of molar volumes. They have slight positive deviations from the additive straight line.

The methodological specificity of measuring surface tension by the methods of large drop and maximum pressure in a drop

“…F. Bashfort and J. Adams [13] were the first to carry out numerical integration for the Laplace equation (3). At present, this equation is being solved with high accuracy by the methods of modern information technology.…”

“…A critical analysis of the main methods for measuring the surface tension of liquids is given in [1,3]. Therefore, we do not dwell on the analysis of other methods for measuring surface tension, and note that the advantages of the lying (large) drop method include the following:…”

“…However, as it will be shown below, a comparative analysis of the experimental data on the temperature dependence of the ST of pure metals obtained by these methods shows that they differ markedly from each other, and these discrepancies for some metals go even beyond the total error in measuring the ST. It should be noted that the ST values of the studied metals, obtained by the "large" drop method, always numerically exceed the results of ST measurements by the maximum pressure in a drop method [1][2][3][4], which indicates that these discrepancies are not associated with the influence of a random error, and are due to factors, the direction of which is the same. The nature of these factors and the reason for such discrepancies has not yet been clarified and, in our opinion, the analysis of the methodological features of measuring the surface tension by both methods in order to identify the degree of influence of each of the random factors on the ST measurement error is of a certain scientific and practical interest.…”

Concentration Dependence of the Surface Tension of Three and Four-Component Systems with Peculiarities in the Surface Tension Isotherms of Lateral Binary Melts

“…In-Sn-Pb-Bi system melts were studied in a combined device developed and constructed in our laboratory [2]. The surface tension in it is measured by the method of maximum pressure in a drop, and the density -by an improved areometer (Fig.…”

“…The indium-tin system has been studied by various authors [3][4][5] and methods. A comparative analysis of the ST concentration dependence of this system, explored by two independent methods: the method of maximum pressure in a drop and a lying drop method, was carried out in paper [6]. It was revealed that the isothermal surface of the indium-tin system was characterized by the presence of a minimum in the area of average compositions.…”