A Novel Vibrating Finger Viscometer for High-Temperature Measurements in Liquid Metals and Alloys

Abstract

A novel vibrating finger viscometer for high-temperature measurement in liquid metals and alloys up to 1823 K was constructed. The dynamic viscosity ($\eta$) of the liquid fluid is measured as a product of $(\rho \cdot \eta )^{0.5}$ and the relative change of the field coil input for a constant amplitude recording at the resonant frequency of the oscillator. The viscometer was calibrated at 298 K using reference silicon oils with varying kinematic viscosities ($\nu$), $(0.79\hbox { to } 200)\times 10^{-6}\hbox { m}^{2}\cdot \hbox {s}^{-1}$. In the present study, the viscosity of liquid gold ($99.99\,\%$ Au), silver ($99.9\, \%$ Ag), and tin ($99.9\,\%$ Sn) was measured. The viscosities expressed as an Arrhenius function of temperature are:

$$\begin{aligned} \hbox {for Au:}\quad \quad \hbox {ln }\eta= & {} -0.1990+\frac{2669}{T}\\ \hbox {for Ag:} \quad \quad \hbox {ln }\eta= & {} -0.4631+\frac{2089}{T}\\ \hbox {for Sn:} \quad \quad \hbox {ln }\eta= & {} -0.5472+\frac{671}{T} \end{aligned}$$

The viscosity values are consistent within the range of available literature data.