Eutectic tin-aluminium alloy can be the ground for the creation of new micro- and nanocomposite solders for the flux-free soldering of aluminium and its alloys [1]. However, reliable data on polytherms of density and surface tension of this alloy are not known. That is why the temperature dependences of densityrand surface tensionsof eutectic tin-aluminium alloy are studied here in broad temperature range using the method of a large drop in the graphite cup.
All the experiments were performed under the residual gas pressure of about 0,01 Pa. The data were processed using the up-to-date program software [2]. The images of longitudinal sections of drops were fixed using the digital photo camera.
To remove the oxide layer on the surface the drops were heated up to 1100 K and the measurements took place while cooling down to melting point.
It is shown that the density and surface tension polytherms of eutectic tin-aluminium alloy could be approximated by the linear equations with negative slopes. The terms for straights r = 568,8 – 0,054 Т and s = 7375,2 – 0,49 Т, obtained by the least squares method, resemble those of pure tin but are little bit shifted.
Obtained results can find application at devising new composite lead-free solders for flux-free soldering of aluminium and its alloys.
This research is supported by the Russian Ministry of Education and Science (Project No 16.552.11.7030)
[1] Sozaev V.A., Shidov Kh.T., Shuhostanov A.K. USSR Patent № 1274907. V23K35126. Publ. 07.11.92 – Bull. 41
[2] Direktor L.B., Kashezhev A.Z., Maikov I.L., Mozgovoy A.G., Ponegev M.Kh., Sozaev V.A. Software for calculation of thermophysical properties of liquids / Abstracts of the Interdisciplinary seminar “Technology of alkali liquid-metal heat carriers” (Thermophysics-2009), 28-30 October 2009. – Obninsk, 2009. – p. 46-47. [in Russian]