Impulse Magnetization of Nd-Fe-B Sintered Magnets for Sensors
نویسندگان
چکیده
Magnetization of large Nd-Fe-B sintered permanent magnets is still challenging. This type of permanent magnet is electrically conductive, so impulse magnetization causes a flow of eddy currents which prevent magnetization of the whole volume of the magnet. The paper deals with the impulse magnetization of sintered Nd-Fe-B permanent magnets and shows a method for the determination of suitable parameters for the supply system. The necessary magnetic field strength for magnetization of the magnet to saturation was determined. The optimal magnetizing fixture supply voltage for magnetization to saturation was determined from simulations in PSpice software, finite element analyses in Maxwell 15 and measurements. Measurements of magnetic induction on the surface of the Nd-Fe-B magnet are also presented to ensure that a magnet with 70 mm diameter and 20 mm in height is fully saturated.
منابع مشابه
Relation between domain wall motion and coercivity in Nd-Fe-B sintered magnets prepared in various conditions
For the study of the relationship between the domain wall motion (DWM) and the coercivity in the samples of Dy-free Nd-Fe-B sintered magnets, the DC susceptibility (χDC) in the initial magnetization from the thermally demagnetized state and the DWM in the partially demagnetized state after the full magnetization in 5T-pulse field were measured. In the high coercivity (μ0Hc) samples of μ0Hc=1.35...
متن کاملEffect of Post-Sintering Annealing Treatment on Magnetic Properties of Some Nd Fe b Based Magnets
Effects of post-sintering annealing treatment between 300 and 1000ºC for up to 8 hrs time periods followed by either furnace cooling (FC) or air-cooling (AC) on the hard magnetic properties of some Nd-Fe-B based sintered magnets was investigated. It was shown that the intrinsic coercivity (Hci), second quadrant demagnetization loop shape and thus the energy density (BH)max varied considerably a...
متن کاملCoercivity enhancement of Nd-Fe-B sintered magnets by grain boundary modification via reduction-diffusion process
The interface between the Nd2Fe14B particles and the grain boundary surrounding them in Nd-Fe-B sintered magnets was modified by diffusion Dy metal selectively through the grain boundary involving the reduction of Dy2O3 or DyF3 with CaH2 and the coercivity of them was effectively enhanced from 0.98 MA/m to 1.42 MA/m with keeping the high value of remanence. The resultant coercivity was higher t...
متن کاملSintering of Nd-Fe-B Magnets from Dy Coated Powder
High-coercive (Nd,Dy)-Fe-B magnets were fabricated via dysprosium coating on Nd-Fe-B powder. The sputtering coating process of Nd–Fe–B powder yielded samples with densities greater than 98%. (Nd,Dy)2Fe14B phases may have effectively penetrated into the boundaries between neighboring Nd2Fe14B grains during the sputtering coating process, thereby forming a (Nd,Dy)2Fe14B phase at the grain boundar...
متن کامل