Title :
Precipitation in NdFeB-type magnet materials
Author :
Parker, S.F.H. ; Pollard, R.J. ; Lord, D.G. ; Grundy, P.J.
Author_Institution :
University of Salford, Salford, U.K.
fDate :
9/1/1987 12:00:00 AM
Abstract :
The microstructure of sintered magnets and melt-spun samples made from Nb-containing (Nd,Dy)FeB material has been investigated using transmission and scanning electron microscopy, X-ray microanalysis and thermogravimetric analysis. Comparison of the sintered specimens with NdDyFeB and NdFeB magnets revealed the existence of two additional phases. One of these is an Fe2Nb Laves compound. The second additional phase takes the form of small Nb-containing coherent precipitates within the main Nd2Fe14B grains. In the sintered magnet these particles ranged in size from 20-50 nm. Melt-spun ribbon contained a dispersion of smaller inclusions, typically 5-10 nm in diameter. The presence of these precipitates may be related to the enhanced coercivity found in the magnet and melt-spun samples.
Keywords :
Niobium materials/devices; Permanent magnet materials; Coercive force; Iron; Magnetic analysis; Magnetic force microscopy; Magnetic materials; Microstructure; Neodymium; Niobium; Scanning electron microscopy; Transmission electron microscopy;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.1987.1065299
