Title :
Control of ordering and microstructure in Pr-Co and Sm-Fe alloys for permanent magnets
Author :
Meacham, B.E. ; Shield, J.E. ; Branagan, D.J.
Author_Institution :
Dept. of Mater. Sci. & Eng., Utah Univ., Salt Lake City, UT, USA
fDate :
7/1/2001 12:00:00 AM
Abstract :
In this study, the structural state and microstructural scale of Pr2Co17 and Sm2Fe17 were modified by rapid solidification and alloying. Partial suppression of the dumbbell ordering was accomplished by melt spinning, and more effective suppression, leading to the formation of the TbCu7-type structure, was accomplished by the addition of Ti or Ti and C. Annealing recovered the order, although Ti and TiC significantly affected the kinetics in the Sm-Fe system. The addition of Ti and C refines the grain size in both Pr-Co and Sm-Fe. The degree of order was found to influence the coercivity in the nitrided Sm-Fe alloys. The Pr-Co alloys were found to have a planar easy magnetization direction at all levels of ordering
Keywords :
annealing; cobalt alloys; coercive force; ferromagnetic materials; grain size; iron alloys; magnetisation; melt spinning; order-disorder transformations; permanent magnets; praseodymium alloys; rapid solidification; samarium alloys; Pr-Co alloy; Pr2Co17; Sm-Fe alloy; Sm2Fe17; alloy design; annealing kinetics; coercivity; dumbbell ordering; easy axis; grain size; magnetization; melt spinning; microstructural engineering; nitridation; order-disorder transition; permanent magnet; rapid solidification; structural state; Alloying; Annealing; Argon; Cobalt alloys; Iron alloys; Microstructure; Permanent magnets; Power engineering and energy; Samarium alloys; US Department of Energy;
Journal_Title :
Magnetics, IEEE Transactions on
