Prediction of liquid metal viscosities using an adjustable hard sphere radial distribution curve

Predictions of liquid metal viscosities have been made using the Born-Green equation. The pair potential was calculated by the Percus-Yevick and hypernetted chain equations with the predicted structure factor and was used with the Mie-Gruneisen potential to make the calculations. Instead of using an experimentally determined radial distribution curve, however, an adjustable hard sphere radial distribution curve is employed to obtain the pair potential. The first peak of the hard sphere radial distribution curve used here was adjusted to represent the radial distribution curve at the melting point for any liquid metal. This was done by using the number of nearest neighbors and the distance to the first maximum in the radial distribution curve. This is possible because of the similarities in the radial distribution curves of liquid metals. A temperature correction is employed so that the viscosities can be calculated over a wide temperature range. The results are compared with literature values.     

Accurate predictions for the viscosities of several liquid transition metals, plus barium and strontium

Recently, the authors presented two models for accurate predictions of the viscosity for pure liquid metals. In this article, the authors checked the models against the viscosities of various liquid high-melting-point metals. These two models give very good agreement with experiment. Using these two models, the viscosities of liquid transition and Group IIA metals were predicted for dysprosium, erbium, molybdenum, neodymium, platinum, scandium, vanadium, yttrium, barium, and strontium. Finally, recommended data were collected for the experimental viscosities of pure liquid metals.     

Maximum magnetic permeability of magnetically hard steel and the limiting hysteresis loop

The proposed formula relates the maximum magnetic permeability μ _m of magnetically hard steel to its coercive force and residual magnetization. The calculation results may be used in nondestructive quality assessment of heat treatment and in magnetic structural analysis of steel, instead of the measurement of μ _m , which is laborious and less precise.     

A rigorous equation of state for solids,liquids, and gases

In this research report, a rigorous equation of state is derived. Only thermodynamic relationships are used in the derivation, and hence, no restrictive or conditional model is assumed. The advantage of an equation of state that is based on thermodynamic principles is that, by definition, it is applicable to all substances, solid, liquid, or gas. It can, therefore, be used to provide a theoretical insight into other equations of state, notably the van der Waals equation, and as a consistency check for measured thermodynamic data in general. The behavior of the terms in the equation, at and near the critical point, is defined.     

The viscosities of lead,tin, and Pb-Sn alloys

The viscosities of lead, tin, and Pb-Sn alloys have been determined by an absolute technique using an oscillational viscosimeter. By careful experimentation, it has been possible to obtain results which are accurate to within ±0.5 pct. For the pure metals, the data are in good agreement with some recent work. The results obey Andrade’s equation ηv^1/3 = A expC/vT, the constants having values ofA = 2.54 × 10⁻³ and C = 86.30 for lead, andA = 2.75 × 10⁻³ and C = 88.49 for tin. No evidence has been found to support the reports of some investigators that Pb-Sn alloys experience structural changes or abnormal interatomic reactions in any specific composition ranges such as around the eutectic. The results confirm recent work that isothermal viscosities vary with composition in a linear manner. Formerly Research Scientist, Department of Energy, Mines and Resources, Ottawa, Canada