Title :
A study of the microstructures and the effects of coating on Nd2Fe14B alloys
Author :
Ahmad, A. ; McGuiness, P.J. ; Harris, I.R.
Author_Institution :
Sch. of Metall. & Mater., Birmingham Uniiv., UK
fDate :
9/1/1990 12:00:00 AM
Abstract :
The microstructures of a range of as-cast and homogenized Nd-Fe-B-type alloys have been investigated. In the as-cast condition, all of the materials with compositions close to that of stoichiometry contain elemental free iron. Results indicate that this free iron can be removed completely from the Nd12.28Fe81.87B5.85 (Nd2.1Fe 14B) alloy by homogenization. Fine particles of the homogenized alloys and of the as-cast Nd12.94Dy1.56Fe77.63Nb1.01B 6.86 alloy (which did not contain free iron) were coated with mechanically soft metals such as copper, aluminium, and zinc, and the magnetic properties of rotary-forged compacts produced from these powders were measured. Aluminum-bonded rotary-forged compacts were also produced by mixing the fine particles of RFeB alloys with aluminum powder. The compacts produced from Nd12.94Dy1.56Fe 77.63Nb1.01 B6.86 alloy particles showed the best coercivity
Keywords :
boron alloys; coercive force; crystal microstructure; ferromagnetic properties of substances; iron alloys; magnetic properties of fine particles; neodymium alloys; permanent magnets; Nd12.28Fe81.87B5.85; Nd12.94Dy1.56Fe77.63Nb1.01 B6.86; Nd2Fe14B; as-cast; coating; fine particles; homogenization; homogenized; magnetic properties; microstructures; rotary-forged compacts; stoichiometry; Aluminum alloys; Coatings; Composite materials; Copper alloys; Iron alloys; Microstructure; Neodymium; Niobium alloys; Powders; Zinc;
Journal_Title :
Magnetics, IEEE Transactions on
