J. Phys. III France
Volume 2, Numéro 2, February 1992
Page(s) 267 - 273
DOI: 10.1051/jp3:1992125
J. Phys. III France 2 (1992) 267-273

Effect of grain size distribution on the properties of sintered (Nd, Dy)-(Fe, Co)-B magnets

S. Szymura1, Yu. M. Rabinovich2, H. Bala3, V. V. Sergeev2 and L. V. Potapova2

1  Institute of Physics, Technical University, PL-42-200 Czestochowa, Poland
2  All-Union Science-Research Institute of Electromechanics, VNIIEM, 107817 Moscow, U.S.S.R.
3  Institute of Chemistry, Technical University, PL-42-200 Czestochowa, Poland

(Received 6 August 1991, revised 31 October 1991, accepted 4 November 1991)

The effect of grain size and grain size distribution on magnetic properties of the sintered Nd 14Dy 1.5Fe 68.5-Co 5Al 1Cr 2.5B 7.5 permanent magnet was investigated. As the average grain size or the volume fraction of the large grains increased, the magnetic properties were reduced. The heterogeneous grain size distribution causes kink on the demagnetization curve. The effect of intrinsic coercivity $(_{\rm i}H_{\rm c})$ on the thermomagnetic properties was estimated by measuring $_{\rm i}H_{\rm c}$ and irreversible flux losses at elevated temperature.

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