Title :
Effects of Nb addition and/or casting method on the amount of precipitated Fe in NdFeB alloys
Author :
liu, W.L. ; Liang, Y.L. ; Ma, B.M. ; Bounds, C.O.
Author_Institution :
Rhone-Poulenc Basic Chemicals, Cranbury, NJ, USA
fDate :
9/1/1992 12:00:00 AM
Abstract :
A novel method has been developed to measure the amount of precipitated Fe in a series of (Nd0.9Dy0.1)x Fe93.5-x-yNbyB6.5 alloys, where x=13, 14, 15, or 17, and y=0 or 0.5. It has been found that the amount of precipitated Fe decreases significantly with increasing rare earth content. Nb has been found to suppress the amount of precipitated Fe by approximately 50% for all compositions studied. Rapid solidification via an inert gas atomization process has been used to further suppress the amount of precipitated Fe in (Nd0.9Dy 0.1)xFe93-xNb0.5B6.5 where x=13 and 14. The amount of precipitated Fe can be efficiently decreased, overcoming the problems suggested by the equilibrium phase diagram for these alloys. It is concluded that inert gas atomization offers a promising means to produce alloy powders with fewer Fe-precipitates, and thus sintered magnets with superior magnetic properties and corrosion resistance
Keywords :
boron alloys; directional solidification; dysprosium alloys; ferromagnetic properties of substances; iron alloys; magnetisation; neodymium alloys; niobium alloys; permanent magnets; phase diagrams; precipitation; rapid solidification; (Nd0.9Dy0.1)xFe93.5-x-y NbyB6.5; NdFeB alloys; casting method; corrosion resistance; equilibrium phase diagram; inert gas atomization; magnetic properties; precipitated Fe; rapid solidification; sintered magnets; Casting; Chemicals; Composite materials; Corrosion; Iron alloys; Magnetic properties; Microstructure; Niobium alloys; Optical microscopy; Permanent magnets;
Journal_Title :
Magnetics, IEEE Transactions on
