Viscosity Measurements of Ionic Melts at Temperatures to 1100°C

Abstract
An extension of the theory of the oscillating crucible gives an equation in η½ which is particularly useful as an absolute method for viscosity calculation. While more complex in theory, the oscillating crucible possesses useful advantages for high temperatures, namely, the features of a small flat temperature zone, and of a completely sealed sample container. Use of a closely fitting liner in the crucible offers a further advantage in that an exchange of the melt container is possible without any changes in the experimental assembly. Results are reported for a number of ``reference'' liquids at 25°C and at 440°C (KNO3), and for CaCl2(785–970°C) and BaCl2(985–1040°C). An error analysis shows that the precision is extremely sensitive to the decrement, δm; this appears as the largest error source. An error of viscosity of ±4% is calculated.
Keywords