Title :
Experimental Proof of Microwave Sintering of Nd–Fe–B Powders Toward Fabrication of Permanent Magnets
Author :
Margarit, Gjoka ; Neil, Dan ; Hadjipanayis, George ; Niarchos, Dimitri G.
Author_Institution :
Inst. of Nanosci. & Nanotechnol., NCSR Demokritos, Athens, Greece
Abstract :
The Nd-Fe-B magnets were prepared using conventional and microware sintering processes. A finely tuned microwave cavity operating in the 2.45 GHz, which works in single mode of electric field (e-field), was used to investigate the microwave sintering of Nd-Fe-B powders. The highest sintering temperature used was 1173 K, and the sintering lasted up to 610 s. The density of microwave sintered Nd-Fe-B magnets could reach values as high as 7.43 g/cc. We have managed to sinter Nd-Fe-B powders and produce magnets at a fraction of the time and energy used in conventional resistive/radiant heating, which is in excess of 1273 K for many hours, and in many cases after homogenization at high temperatures.
Keywords :
boron alloys; heat treatment; high-temperature effects; iron alloys; magnetic particles; microwave materials processing; neodymium alloys; permanent magnets; powders; sintering; NdFeB; conventional resistive-radiant heating; conventional sintering processes; finely tuned microwave cavity; frequency 2.45 GHz; high-temperature homogenization; microwave sintering processes; permanent magnets; powders; single electric field mode; temperature 1173 K; time 610 s; Coercive force; Electromagnetic heating; Microwave FET integrated circuits; Microwave imaging; Microwave integrated circuits; Microwave theory and techniques; Powders; Coercivity; material preparation; microwave ovens; permanent magnets;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2014.2321483
