Contactless measurement of temperature-dependent viscosity and surface tension of liquid A169.1CU12.8Ag18.1 eutectic alloy under microgravity conditions using the oscillating-drop-method.

Thermophysical properties of the A169.1Cu12.8Agl eutectic liquid alloy are of particular interest for support of self-and inter-diffusion studies. In the presented work. A169.1Cu12.8Agl-samples were processed contactlessly by electromagnetic levitation under microgravity conditions using the TEMPUS facility. The measurements were performed onboard the Airbus A310 Zero-G in parabolic flight campaigns. The oscillating-drop-method (ODM) was used for measurements of the viscosity via oscillations damping and surface tension via oscillations frequency. These were determined for temperatures in the range of 900-1500 K by analysis of the oscillation spectrum obtained from the electrical impedance. The latter was measured using the Sample Coupling Electronics. An Arrhenius-law η(T) ηexp(EηR/T) was used to fit the temperature-dependent viscosity data. The resulting fit parameters were η = (0.632 * 0.160) mPas and activation energy of viscous flow Eη = (2.344 * 0.233) ·10+4 j/mol. A linear law γ(T) = γl +γT (T-Tm) was fit to the surface tension data yielding % = (0.9013 * 0.02625) Nm and γr = -(0.7462 zE 0.2675) · 10-4Nm-1K-1. The Kozlov-model was applied to determine the enthalphyofmixing as AHmix = - (18.576 20.018) Id/mol. [ABSTRACT FROM AUTHOR]