The Variation of Magnetic Properties of Fe-Based Amorphous Alloys Along the Ribbon Length

1981 ◽  
Vol 8 ◽  
Author(s):  
Takashi Sato ◽  
Tsutomu Ozawa ◽  
Toshio Yamada ◽  
Ryutaro Matsumoto

ABSTRACTThe variation of ac magnetic properties along the length of melt-spun Fe-based amorphous ribbons was examined in relation to the variations of the roller surface temperature and the ribbon thickness. The results indicated that the lengthwise variation of magnetic properties strongly depends both on the roller surface temperature and the ribbon thickness. The critical cooling rates at which core loss begins to increase were determined from the relationship between core loss and cooling rate. For ribbons cast at lower cooling rate than critical cooling rate, the finedomain patterns were usually observed on the free surface. From the disappearance of the fine-domain pattern and the remarkable decrease of core loss by removal of the surface layers, it is ascertained that the surface layers deteriorate magnetic properties.

2001 ◽  
Vol 674 ◽  
Author(s):  
N. Lupu ◽  
H. Chiriac ◽  
A. Takeuchi ◽  
A. Inoue

ABSTRACTBulk rods with diameters up to 3 mm prepared by suction casting and respectively mould casting and melt-spun amorphous ribbons with thicknesses in the range 25 – 150 μm with compositions Nd90−xFexAl10 (x = 35; 40; 45; 50) were investigated by XRD, DSC and magnetic measurements in the temperature range 5 – 600 K. The microstructure and magnetic properties are strongly dependent on the cooling rate, preparation process and Fe content. The large values of the coercive field, which amount to 320 kA/m in the as-cast state as well as the increase with decrease of the temperature and cooling rate result from the formation of very small metastable or nonequilibrium magnetic clusters.


2000 ◽  
Vol 644 ◽  
Author(s):  
Akihiro Makino ◽  
Akihisa Inoue ◽  
Tuyoshi Masumoto

AbstractThe structure, the soft magnetic properties and the core losses for Fe-Zr-Nb-B(-Cu) nanocrystalline alloys were investigated. It has been already reported that the typical ternary nanocrystalline Fe90Zr7B3 and Fe84Nb7B9 alloys exhibit good soft magnetic properties and a small negative and a small positive magnetostriction (λs), respectively. The soft magnetic properties of the nanocrystalline Fe84–90(Zr, Nb)7B3–9 quaternary alloys with mixed compositions of Fe90Zr7B3 and Fe84Nb7B9 cannot be improved whereas very small magnetostrictions are obtained. The quaternary alloys with 7 at% (Zr + Nb) have structures of an amorphous with α-Fe phases on the free and roll-contacted surfaces at an as-quenched state. The crystalline surface layers deteriorate the soft magnetic properties at a crystallized state. The high saturation magnetic induction of 1.64 T, the high permeability of 60,000 at 1 kHz and the very low core loss of 0.9 W/kg at 1.4 T and 50 Hz are obtained for the Fe85.5(Zr1/3Nb2/3)6B8.5 alloy containing 6 at% of (Zr + Nb) content with nearly zero-λs produced by crystallizing the single amorphous phase without the crystalline surface layers. The thermal stability of the core loss of the quaternary alloy is significantly higher than that of the Fe78Si9B13 amorphous alloy. The crystalline surface layers of the Fe84–90(Zr, Nb)7B3–9 quaternary alloys disappear by 1 at% Cu addition, which results in significant improvement of the soft magnetic properties at a crystallized state.


1980 ◽  
Vol 19 (1-3) ◽  
pp. 149-151 ◽  
Author(s):  
L. Novák ◽  
L. Potocký ◽  
A. Lovas ◽  
É. Kisdi-Koszó ◽  
J. Takács

2019 ◽  
Vol 70 (1) ◽  
pp. 233-235
Author(s):  
Joanna Gondro

In this paper the results of the structural and magnetic properties for amorphous alloys ribbons Fe86Zr7Nb1Cu1B5 and Fe86Zr4Y3Nb1Cu1B5 were presented. From X-ray diffraction and M�ssbauer investigations we have stated that amorphous ribbons were fully amorphous. The investigated alloys, exhibit poor soft magnetic properties at room temperature. However, at low temperatures they show relatively large magnetic susceptibility and good its time stability.


Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.


1988 ◽  
Vol 49 (C8) ◽  
pp. C8-1325-C8-1326
Author(s):  
P. Sánchez ◽  
M. C. Sánchez ◽  
E. López ◽  
M. García ◽  
C. Aroca

Alloy Digest ◽  
1999 ◽  
Vol 48 (1) ◽  

Abstract Armco DI-MAX nonoriented electrical steels have practically identical magnetic properties in any direction of magnetism in the plane of the material. They have superior permeability at high inductions, low average core loss, good gage uniformity, excellent flatness, and a high stacking factor. This datasheet provides information on composition, physical properties, hardness, and tensile properties. Filing Code: FE-88. Producer or source: Armco Inc., Specialty Steels Division. Originally published April 1989, revised January 1999.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4010
Author(s):  
Monika Gwadera ◽  
Krzysztof Kupiec

In order to find the temperature field in the ground with a heat exchanger, it is necessary to determine temperature responses of the ground caused by heat sources and the influence of the environment. To determine the latter, a new model of heat transfer in the ground under natural conditions was developed. The heat flux of the evaporation of moisture from the ground was described by the relationship taking into account the annual amount of rainfall. The analytical solution for the equations of this model is presented. Under the conditions for which the calculations were performed, the following data were obtained: the average ground surface temperature Tsm = 10.67 °C, the ground surface temperature amplitude As = 13.88 K, and the phase angle Ps = 0.202 rad. This method makes it possible to easily determine the undisturbed ground temperature at any depth and at any time. This solution was used to find the temperature field in the ground with an installed slinky-coil heat exchanger that consisted of 63 coils. The results of calculations according to the presented model were compared with the results of measurements from the literature. The 3D model for the ground with an installed heat exchanger enables the analysis of the influence of miscellaneous parameters of the process of extracting or supplying heat from/to the ground on its temperature field.


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