Measurement of viscosities of metals and alloys with an oscillating viscometer

An oscillating viscometer with the following features has been successfully constructed: improved detection of the logarithmic decay curve of oscillation through the introduction of a system with a 40-diode array; use of the Roscoe equation to derive viscosities from the decay curve; the introduction of a high-temperature two-zone furnace to provide a uniform temperature zone for temperatures up to 1650 degreesC. Viscosity measurements have been carried out on mercury, tin, aluminium, copper, nickel, and iron and viscosities were in good agreement with the recommended values except in the case of iron. However, the results of the present study are in excellent agreement with viscosities of iron reported recently by Sate et al. Viscosity measurements are reported for nickel-based superalloys, for steels, and for the aluminium alloys LM25 (or A356). An analysis of potential uncertainties in the measurements has been carried out.