I. V. Slinkin, O. A. Chikova, V. V. Vyukhin.
ABSTRACT
Neodymium is one of the most widely used rare earth metals, the main amount of neodymium is used for the manufacture of permanent magnets. Experimental data on the physicochemical properties of neodymium and Fe–30% Nd–1% B–1% Co–1% Dy in the liquid state are presented. Initially, in the production of NdFeB magnets, an ingot Fe–30% Nd–1% B–1% Co–1% Dy is prepared. The kinematic viscosity and resistivity of liquid neodymium Nd (99.85%) and kinematic viscosity of the melt Fe–30% Nd–1% B–1% Co–1% Dy were measured. The dependence of the kinematic viscosity of the neodymium melt on the temperature is described by the Arrhenius–Frenkel–Eyring equation and is consistent with the results of the theoretical calculation. The temperature dependence of the kinematic viscosity of the melt Fe–30% Nd–1% B–1% Co–1% Dy is anomalous in the temperature range from 1320 to 1550°C-viscosity increases with temperature. The authors describe the increase in viscosity with temperature, the so-called “quasi-gas” behavior of the melt, within the framework of physical chemistry concepts using the concept of molar viscosity. The dependence of the resistivity of liquid neodymium on the temperature is described by a linear equation. The measured resistivity of the neodymium melt is 30% higher than the experimental data obtained by other researchers. The results of measurements will be used to optimize the parameters of metallurgical production of sintered permanent magnets Ural Strip Casting NdFeB.
KEYWORDS
neodymium, alloy Fe–30% Nd–1% B–1% Co–1% Dy, melt, viscosity, resistivity
DOI:10.31857/S0235010620030093