Title :
Evolution of stable and metastable phases and coercivity in rare-earth-rich alloys of the Fe-Nd and Fe-pr systems
Author :
Cabral, F.A.O. ; Gama, S.
fDate :
9/1/1990 12:00:00 AM
Abstract :
Eutectic alloys of the Fe-Nd and Fe-Pr systems were studied in connection with their magnetic behavior in the as-cast state and heat-treated at 600°C for different periods. In both systems, the initial precipitation of a metastable phase is observed. This phase first transforms into Fe17Nd2 and then into a second phase with Fe17Nd5 stoichiometry that is stable. For the Fe-Pr system, the precipitation of two metastable phases that transform into the stable Fe17Pr2 is observed. The shape of the TMA (thermal magnetic analysis) curve changes with the heat-treatment time at 600°C. It changes from a Hopkinson peak to a step. A marked decrease in the coercive field and a drastic change in the microstructure of the samples are observed for both systems
Keywords :
coercive force; crystal microstructure; eutectic alloys; ferromagnetic properties of substances; iron alloys; neodymium alloys; praseodymium alloys; precipitation; 600 degC; Fe-Nd; Fe-Pr; Fe17Nd2; Fe17Nd5; Fe17Pr2; Hopkinson peak; as-cast state; coercivity; eutectic alloys; heat-treated; magnetic behavior; metastable phases; microstructure; precipitation; stable phases; stoichiometry; thermal magnetic analysis; Coercive force; Iron alloys; Magnetic analysis; Magnetic field measurement; Metastasis; Microstructure; Neodymium; Silicon compounds; Thyristors; Water heating;
Journal_Title :
Magnetics, IEEE Transactions on
