Characterization and optimization process of amorphous Metallic Glass ribbons for transformer cores

Abstract

An amorphous metallic glass ribbons (100) of Fe-Si-B (unannealed) for transformer cores (112)

Specification

Description:Magnetic materials found to occupy a prominent place in Engineering industry and in our daily lives. The soft magnetic materials find application as materials for electrical engineering and power electronics which are used in the production, transportation, and the use of electrical energy like dynamos and alternators, electromagnets, low power transformers, motors. In electrical power generation and transmission, the greatest demand is for transformer cores. The materials used for the transformer cores is almost exclusively grain- oriented silicon-iron. These transformers are used in the power generation. High frequency transformers use cobalt-iron. These transformers operate under a.c. conditions and require (μ) of the core and also low electrical conductivity to reduce the eddy current losses. In the transformer core the material used is grain-oriented silicon-iron alloy with 3- 4% Silicon. In distribution transformers, which supplies power to residences, stores, offices and small industries the principal characteristic is that they are put in service for a period of 25-40 years and during that time the primary coil is continuously energized by the utility supply. The significance of this duty pattern is that the magnetic core material linking the primary and the secondary coils is thus cycled around its B-H loop at the line frequency continuously for up to 40 years. The metallic glasses especially amorphous-metal cored transformers like silicon-iron transformers are used to obtain 99% of efficiency by reducing the core losses. The materials of present study are Fe-Si-B, prepared for soft magnetic applications. , C , C , Claims:1. An amorphous metallic glass ribbons (100) of Fe-Si-B (unannealed) for transformer cores (112);
2. An amorphous metallic glass ribbons (100) As claimed in claim 1 consists of sample A (101) and sample B (102) are characterized by XRD (103) confirm amorphous in nature with short range periodicity and are associated with d-spacings 3.56 Å and 2.014 Å respectively;
3. An amorphous metallic glass ribbons (100) As claimed in claim 1 the sample A (101) and sample B (102) are characterized by SEM (104). The micrographs reveal that both the samples have a homogeneous matrix in which a few regions of precipitates exist as defects. Also, the shape of the crystallites in sample A (101) is rather spherical and most of them are of 1-10 μm size. In comparison, the crystallites in the sample B (102) are of varied shapes and sizes distributed in a range of 5-40 μm;

4. An amorphous metallic glass ribbons (100) As claimed in claim 1 the sample A (101) and sample B (102) are characterized by EDAX (105). A compositional study using EDAX (105) in the matrix suggested sample A (101) to have Fe and Si in the ratio 85:15 while sample B (102) had Fe and Si in the ratio 86:14. A study of this data reveals that the spherical precipitates seen in sample "A" (101) has Fe3S composition. In sample B α-Fe precipitates out with smaller grain size ~ 5 μm;
5. An amorphous metallic glass ribbons (100) As claimed in claim 1 the two samples A (101) and B (102) were characterized by DSC (106) technique. Two different intensive exothermic peaks appear at around 509oC and 551oC is observed for sample A (101), Similarly, from the DSc scan of sample B (102) two intensive exothermic peaks appear at around 479oC and 548oC;
6. An amorphous metallic glass ribbons (100) As claimed in claim 1 sample A (101) and sample B (102) are characterized by VSM (107) technique to gain the magnetic parameters saturation magnetization (Ms) (108) and induction (Bs) (109), coercive field (Hc) (110) and remanent magnetization (Mr) (111);

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