Viscosities of liquid metals

The viscosities of liquid metals vaty by a factor of about 10 between the empty metals, and the full metals, and typical values are 0.54 x 10 poise for liquid potassium, and 4.1 x 10 poise for liquid copper, at dreir respective melting points. Empty metals are those in which the ionic radius is small compared to the metallic radius, and full metals are those in which the ionic radius is approximately the same as tire metallic radius. The process was described by Andrade as an activated process following an AiThenius expression... 

A furtlier empiiical expression, due to Andrade, for die viscosity of liquid metals at tlreir melting points, which agrees well with experimental data is... 

The viscosity coefficients at dislocation cores can be measured either from direct observations of dislocation motion, or from ultrasonic measurements of internal friction. Some directly measured viscosities for pure metals are given in Table 4.1. Viscosities can also be measured indirectly from internal friction studies. There is consistency between the two types of measurement, and they are all quite small, being 1-10% of the viscosities of liquid metals at their melting points. It may be concluded that hardnesses (flow stresses) of pure... 

Intrinsic resistance to dislocation motion can be measured in either of two ways direct measurements of individual dislocation velocities (Vreeland and Jassby, 1973) or by measurements of internal friction (Granato, 1968). In both cases, for pure simple metals there is little or no static barrier to motion. As a result of viscosity there is dynamic resistance, but the viscous drag coefficient is very small (10" to 10" Poise). This is only 0.1 to 1 percent of the viscosity of water (at STP) and about 1 percent of the viscosity of liquid metals at their... 

Braze fluidity can be assured only if the joining temperature is higher than the braze liquidus. The viscosities of liquid metals are relatively low, only a few mPa.s, Table 10.1, and decrease slowly as the temperature is raised. A dramatic increase in viscosity can occur, however, if the temperature drops below the... 

The Viscosity of Liquid Metals and an Empirical Relationship between their Activation Energy of Viscosity and their Melting Points. J. Inorg. Nucl. Chem. 23, 333-339 (1961). 

This very simple formula enables the viscosity of liquid metals to be expressed with very satisfactory accuracy as a function of their melting point, as is seen from Table 81. 

The temperature dependence of the viscosity of liquid metals is quite the opposite behavior to that of gases (Fig. A2.7). The viscosity of Na and Pb drop linearly over the whole range of temperature, while the viscosity of Pb—Bi has a slower linear drop, up to 600°C, and then the viscosity increases for temperatures between 600 and 1000°C. Near 1000°C, the viscosity returns to a value close to that measured at 250°C. The viscosities of gases increase linearly with temperature, and the viscosity of SCW at... 

X scosity of Carbon Dioxide along the Saturation Line, 6-202 Viscosity of Gases, 6-196 Viscosity of Liquid Metals, 6-204 to 205 Viscosity of Liquids, 6-197 to 201 Volt... 

Hildebrand JH, Lamoreaux RH (1976) Viscosity of liquid metals an intr retatiotL Proc Natl Acad Sci U S A 73 988-989... 

Viscosity is used to describe the momentum transport within a moving fluid. The viscosity of liquid metals is discussed in detail by lida and Guthrie [32] and Poirier and Geiger [55]. The coefficient of viscosity fi for the laminar flow of a Newtonian fluid is defined by ... 

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