Thick Fe3B/Nd2Fe14B nanocomposite permanent magnet flakes prepared by slow quenching

Thick permanent magnet flakes of Fe3B/Nd2Fe14B nanocomposites have been prepared directly from molten alloys by means of the low surface-velocity melt-spinning technique under a vacuum. Dependence of microstructure and magnetic properties of Nd4Fe77.5B18.5 rapidly solidified alloys have been studied as functions of pressure of a melt-spinner chamber and the surface velocity of a Cu roll. An as-spun alloy of Nd3.5Dy1Fe73Co3Ga1B18.5 Obtained at a V-s = 3.3 m/s under a 1.3 kPa Ar atmosphere has a thickness of 240 mu m and the room temperature magnetic properties of (BH)(max)=131.6 kJ/m(3), B-r = 1.15 T, and H-cJ = 400 kA/m. (C) 1998 American Institute of Physics. [S0021-8979(98)15611-6].