12 research outputs found
Foundation earthing of container substation treated as a building
Artykuł podnosi aspekt stosowanych materia-łów na uziemienia sztuczne i przewody łączące uziom sztuczny łączony z uziomem fundamentowym stacji elektroenergetycznej.The article is focused on materials used for external earthing and conductors connecting the external earthing system with foundation earthing of the substation
57Fe Mössbauer effect study of Nd-Fe-B hybrid bonded magnets
An investigation of magnetic interaction between the particles of hybrid bonded magnets based on mixtures of Nd-(Fe,Co)-B and strontium ferrite powders was carried out. An enhancement of the magnet remanence and coercivity caused by the interaction between their components was observed. From Mössbauer effect study, it results that this enhancement can be correlated with the increase of an average hyperfine field at Fe sites in Nd-(Fe,Co)-B magnets with the strontium ferrite addition
Effect of Preparing Conditions on the Phase Constitution and Magnetic Properties of Nd-Pr-Fe-Zr-B Alloy Ribbons
The aim of presented work was to study influence of preparing conditions on phase constitution and magnetic properties of the RE-Fe-B nanocomposite magnets doped with Zr. X-ray studies carried out for samples obtained under lower pressure of Ar atmosphere (0.6×10⁵ Pa) revealed higher ability to formation of nanocrystalline structure. In case of higher pressure of Ar (0.8×10⁵ Pa) it was possible to obtain full amorphous ribbon during melt-spinning process. The best magnetic properties (means the higher values of coercivity field , remanence and maximum energy product were measured for sample prepared with the lowest copper wheel speed 20 m/s and higher pressure of Ar (0.8×10⁵ Pa)
Struktura domenowa anizotropowego odkształconego na gorąco magnesu na bazie związku Nd-(Fe, Co)-B
The measurements of the recoil curves for the die-upset Nd-(Fe, Co)-B based magnets from different points on the magnetization and demagnetization curves have been carried out by means of the LakeShore vibrating sample magnetometer in an applied magnetic fields up to 2 T. From the recoil curves the so-called Wohlfarth's remanence relationship has been derived. From this it was deduced that the magnetic interaction existing between the magnet grains has a dipolar nature. The existence of the magnetic interaction has been confirmed by magnetic domain observations by using the magnetic force microscopy (MFM). In the area of interaction domains there is the fine scale magnetic contrast resulting from the dipolar interaction between neighboring grains.Za pomocą magnetometru wibracyjnego firmy LakeShore wyznaczono krzywe powrotne dla spęczanych magnesów Nd-(Fe, Co)-B w polu magnetycznym do 2 T. Na podstawie krzywych powrotnych wyznaczono zależność remeanencyjną Wohlfartha. Z zależności tej wynika, że oddziaływania magnetyczne pomiędzy ziarnami to dalekozasięgowe oddziaływania dipolowe. Obecność tych oddziaływań została potwierdzona przez obserwację struktury domenowej za pomocą mikroskopu sił magnetycznych (MFM). Oscylacyjne zmiany kontrastu, występujące w obszarach zbliżonych do wielkości ziaren, świadczą o istnieniu uporządkowania magnetycznego w tych obszarach, które jest wynikiem oddziaływania dipolowego między sąsiednimi ziarnami
Investigation of the Magnetization Reversal Process of High-Remanent Alloy in the As-Cast State
In this work the magnetic properties of ribbons with composition of obtained by using the melt-spinning method were studied. From the X-ray diffraction patterns the phase composition was determined. It was found that investigated alloy was composed of α-Fe and phases. From the peaks broadening the grain sizes of α-Fe and phases were estimated as equal to 20 nm and 40 nm, respectively. From the recoil curves the reversible and irreversible parts of magnetization and differential susceptibility and were determined as a function of an applied field. From these dependences it was found that the pinning of domain walls at the grain boundaries is the main magnetization reversal process. The interactions between grains were investigated by means of the δ M plot. It was stated that short range exchange interaction between grains of hard and soft phases are dominant and causes the remanence enhancement