Material data measurements of molten Nd2Fe14B

High performance Nd-Fe-B magnets are of enormous economic interest and play a key role in the development of electronics and motors. The excellent ferromagnetic properties of the Rare - Earth magnets are due to the hart magnetic Nd2Fe14B-phase (f-Phase) with high saturation polarization and magnetocrystalline anisotropy. Stoichiometric Nd-Fe-B alloys perform a peritectic reaction under near-equilibrium conditions, and the phase and microstructure selection plays a crucial role on the hard magnetic properties of this material. Besides additions and substitutes, the melt convection strongly influences the microstructure formation of Nd-Fe-B alloys, in particular the volume fraction and grain size of the properitectic g-Fe phase which deteriorates the hard magnetic properties of the material. Numerical simulations are essential in order to understand and design the various flow structures. Therefore, the investigation of electrophysical and structure sensitive properties of the system in the liquid state prior to solidification is very important.
We present new results for the electrical and thermal conductivity, thermoelectric power and viscosity carried out in a temperature range from the liquidus (1553 K) to 1620 K. The electrical conductivity and thermoelectric power were measured using a contact 4-probe method. The thermal conductivity was investigated by a steady-state concentric cylinder method. The shear viscosity measurements were performed using an oscillating-cup viscometer. Special attention was paid to the region close to the liquidus where heating and cooling rates were reduced and the measurement steps shortened to 1 K.