The paper presents electrical actuator design considerations introduced by exploiting new magnetic material characteristics. The materials considered are amorphous alloy ribbons as well as neodymium alloy permanent magnets involving very low eddy current losses. Such materials enable electric machine operation at higher frequencies compared with the standard iron laminations used in the traditi...

Permeability and coercivity are the most important parameters for the evaluation of soft magnetic materials. The criteria for the softest magnetic materials demand very high permeability and / or extremely low coercivity and these properties necessitate the anisotropy energy and the magnetoelastic energy tend towards zero. These unique demands are fulfilled when the FINEMET type of nanocrystall...

Defect states in different dielectric materials with crystalline and amorphous structures were investigated with two models, the Broer model and the Bloch model. For crystalline structures as in hafnium oxide, defects were found to fit well with the Broer model due to strong local magnetic-field-orientation dependency. In amorphous materials, for example, organosilicate glass, defects were foun...

The nanocrystallization of Co67Fe4Cr7Si8B14 amorphous ribbons which prepared by planar flow melt spinning process (PFMS) was investigated. Crystallization of the ribbons was studied by differential thermal analysis (DTA), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The DTA result of amorphous ribbon at heating rate of 10˚C/min showedoccurrence of phase transitions in two...

The magnetic characteristics of FINEMET type glass-coated nanowires and submicron wires are investigated by taking into account the structural evolution induced by specific annealing all the way from a fully amorphous state to a nanocrystalline structure. The differences between the magnetic properties of these ultrathin wires and those of the thicker glass-coated microwires and “conventional” ...

In the present research, amorphous Fe73.5Si13.5B9Nb3Cu1 Finemet foils, 21-26µm in thickness and 5mm in width, were prepared by Planar Flow Casting (PFC) process. Wound cores of amorphous Finemet foils were simultaneously annealed and heat treated at 540°C for 60, 120 and 240 minutes in steam and air flow to form oxide insulating coating layer on both surfaces of the foils. The structure of nano...

This article presents an up-to-date magnetic material investigation and overview on magnetic materials used in rotating electrical machines. The focus is on small to mediumsized high-performance and high-efficiency permanent-magnet and induction motors for different application scenarios. The investigated materials include fully processed silicon-iron, nickeliron, and cobalt-iron lamination ste...

The nanocrystallization processes in Fe-Si-B-Nb-Cu and Fe-Nd-B(-Cu-Nb) amorphous alloys have been studied by transmission electron microscopy (TEM) and a three dimensional atom probe (3DAP). Cu additions are effective in refining the nanocrystalline microstructures of an Fe74.5Si13.5B8Nb3Cu1 alloy and an Fe3B/Nd2Fe14B nanocomposite microstructure. This is because Cu atoms form a high density of...

We present a new mechanism for harmonic generation in magnetorheological (MR) fluids, which differs from the usual ones due to magnetic anisotropy existing in amorphous ferromagnetic materials. Based on thermodynamics, we derive the incremental magnetic susceptibility of the MR fluid which is partially situated in a nonuniform magnetic field, and further extract the desired harmonics analytical...