Papers by Keyword: Soft Magnetic Alloy

Abstract: In this work, we investigated the dynamics of nanocrystallization from the amorphous state of the Fe_72.5Cu₁Nb₂Mo_1.5Si₁₄B₉ alloy together with magnetic phase transformations. The thermomagnetic analysis was performed with the simultaneous recording of the temperature inside the core by a thermocouple and the inductance of the winding wound over the core. It was found that the permeability of the core after the crystallization peak first increases rapidly, and then decreases and stabilizes at some level. Permeability growth begins at a temperature that coincides with the Curie point of the Fe₈₀Si₂₀ solid solution. A decrease in permeability was associated with stabilization of the structure of the amorphous and crystalline phases upon cooling. With decreasing temperature, the active redistribution of chemical elements is suppressed, and silicon atoms occupy a stable position in the crystal lattice of iron. Nanocrystalline cores have different Curie temperatures in the state after the peak of crystallization and 300 seconds after the peak. This indicates the continuation of the diffusion of silicon from the amorphous matrix into Fe-Si nanocrystals for some time after the crystallization peak.

Abstract: The structure and physical properties of the Fe_72.5Cu₁Nb₂Mo_1.5Si₁₄B₉ nanocrystalline alloy have been studied both in terms of dynamics, using thermomagnetic analysis and statics, using specimens subjected to a complete course of heat treatment at the specified annealing temperature. In the course of nanocrystallization, there was a peak detected on the curve of permeability, that peak appeared several minutes later than the heat production peak. The permeability peak occurrence can be related to the formation of a sufficiently large amount of the crystalline ferromagnetic phase α-FeSi followed by saturating it with silicon due to diffusion.

Abstract: The morphology, microstructure and magnetic properties in 1K107 alloy annealed by nitrogen and transversal magnetic (N₂) are studied. The results show that coercivity (H_c), remanence ratio (B_r/B_s), core loss (P_c), and effective permeability (μ_e) are efficiently optimized by transversal magnetic annealing (N₂) according to the methods of digital electric bridge, rectifier bridge, X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM), etc.

Abstract: A new concept is suggested that serves to explain the effects of thermomagnetic treatment. Its validity is proved via measurements of magnetic properties and electron microscopy examination of structure of soft magnetic materials after different treatments. This concept allows one to consciously choose the treatment mode aiming on improvement of magnetic properties of alloys.