Viscosity measurements of metallic melts using the oscillating drop technique

By means of benchmarking reduced gravity experiments, we have verified the measured viscosity of binary Zr-Ni glass forming liquids utilizing the oscillating drop technique combined with ground-based electrostatic levitation (ESL). Reliable viscosity data can be obtained as long as internal viscous damping of a single oscillation mode of a levitated drop dominates external perturbations. This can be verified by the absence of a sample mass dependence of the results. Hence, ESL is an excellent tool for studying the viscosity of metallic glass forming melts in the range of about 10–250 mPa s, with sample masses below 100 mg. To this end, we show that, for binary Zr-Ni melts, the viscosity is qualitatively controlled by the packing density.