Effect of NdF3 and NdCl3 substitution for Nd2O3 on the reduction–diffusion process of Nd–Fe–B powders

Abstract

A method for measuring the pair interaction potential between colloidal particles by extrapolation measurement of collective structure to infinite dilution is presented and explored using simulation and experiment. The method is particularly well suited to systems in which the colloid is fluorescent and refractive index matched with the solvent. The method involves characterizing the potential of mean force between colloidal particles in suspension by measurement of the radial distribution function using 3D direct visualization. The potentials of mean force are extrapolated to infinite dilution to yield an estimate of the pair interaction potential, U (r). We use Monte Carlo (MC) simulation to test and establish our methodology as well as to explore the effects of polydispersity on the accuracy. We use poly-12-hydroxystearic acid-stabilized poly(methyl methacrylate) (PHSA-PMMA) particles dispersed in the solvent dioctyl phthalate (DOP) to test the method and assess its accuracy for three different repulsive systems for which the range has been manipulated by addition of electrolyte.1

Recycling of Nd–Fe–B Sintered Magnets Sludge via the Reduction–Diffusion Route To Produce Sintered Magnets with Strong Energy Density

“…The RD process is a unique method to prepare Nd–Fe–B alloy powders by using rare earth oxides as the raw material and calcium as the reducing agent . Compared with conventional powder metallurgical methods, the RD process exhibits many advantages in energy consumption and production costs to prepare Nd–Fe–B alloy powders suitable for fabrication of Nd–Fe–B sintered magnets with good magnetic properties. , With this new technology, we developed recycled Nd–Fe–B sintered magnets with average magnetic properties. Moreover, the new technology is also capable of treating large volumes of Nd–Fe–B sludge for the mass production of recycled Nd–Fe–B sintered magnets.…”

“…19 Compared with conventional powder metallurgical methods, the RD process exhibits many advantages in energy consumption and production costs to prepare Nd−Fe−B alloy powders suitable for fabrication of Nd−Fe−B sintered magnets with good magnetic properties. 20,21 With this new technology, we developed recycled Nd−Fe−B sintered magnets with average magnetic properties. Moreover, the new technology is also capable of treating large volumes of The sludge was first rinsed with acetone in an ultrasonic cleaning machine for 10 min to remove part of the organic impurities.…”

Synthesis of Nd2Fe14B powders by spray-drying and reduction–diffusion processes

“…The compact was used for Ca reduction and diffusion, which was proceeded under a flowing Ar atmosphere at 1000°C for 2 h. All constituents were reduced and transformed into alloy particles by the solid-state diffusion. 14,19,21 The recovered Nd 2 Fe 14 B particles are sphere shaped with mean particle size of <1 micron [ Fig. 2(d)], which was in a loose state interspersed with fine particles of the by-product CaO.…”