Title :
A new generation of gas atomized powder with improved levels of energy product and processability
Author :
Branagan, D.J. ; Hyde, T.A. ; Sellers, C.H. ; Lewis, L.H.
Author_Institution :
Idaho Nat. Eng. Lab., Lockheed Idaho Technol. Co., Idaho Falls, ID, USA
fDate :
9/1/1996 12:00:00 AM
Abstract :
New alloy compositions have been developed which allow commercially significant levels of hard magnetic properties (>10 MGOe) to be produced by inert gas atomization (IGA). Improvements in magnetic properties are a result of altering the quenching characteristics of the liquid melt by alloying with simultaneous additions of Ti and C. IGA of previous alloy compositions produced powders in an underquenched condition which resulted in inferior hard magnetic properties. In this new generation of IGA alloys, powders are produced in an overquenched condition which results in a nanocrystalline grain structure after crystallization. This extremely fine structure allows the development of a domain structure which is very similar to optimally quenched melt-spun ribbons. Amorphous or partially crystalline structures were verified in powder particles up to 100 μm by magnetic, thermal, and structural experimental methods
Keywords :
X-ray diffraction; alloying additions; amorphous magnetic materials; ferromagnetic materials; magnetic domains; magnetic force microscopy; magnetic particles; nanostructured materials; permanent magnets; powder metallurgy; quenching (thermal); rare earth alloys; remanence; MFM images; TiC modified alloys; X-ray diffraction; alloy compositions; alloying additions; amorphous structures; domain structure; energy product; gas atomized powder; hard magnetic properties; inert gas atomization; magnetic properties improvement; nanocrystalline grain structure; optimally quenched melt-spun ribbons; overquenched condition; partially crystalline structures; powder particles; processability; quenching characteristics; rare earth alloys; Alloying; Amorphous magnetic materials; Amorphous materials; Crystallization; Magnetic domains; Magnetic liquids; Magnetic properties; Nanostructures; Powders; Titanium alloys;
Journal_Title :
Magnetics, IEEE Transactions on
