Effect of Co Substitution on Crystallization and Magnetic Behavior of Fe 85.45-x Co x Cu 0.55 B 14 Metallic Glass

• Published in: Materials Vol. 13; no. 4
• Main Authors: Hawelek, Lukasz, Warski, Tymon, Wlodarczyk, Patryk, Polak, Marcin, Zackiewicz, Przemyslaw, Radon, Adrian, Wojcik, Anna, Kolano-Burian, Aleksandra
• Format: Journal Article
• Language: English
• Published: Switzerland 19-02-2020
• Subjects: magnetic properties; metallic glass; crystallization; soft magnetic materials
• ISSN: 1996-1944; 1996-1944

The effects of Co for Fe substitution on magnetic properties, thermal stability and crystal structure of Fe
Co
Cu
B
(x = 0, 2.5, 5, 7.5, 10) melt spun amorphous alloys were investigated. The Cu content was firstly optimized to minimize the energy of amorphous phase formation by the use of a thermodynamic approach. The formation of crystalline α-Fe type phase has been described using differential scanning calorimetry, X-ray diffractometry and transmission electron microscopy. The classical heat treatment process (with heating rate 10 °C/min) in vacuum for wound toroidal cores was optimized in the temperature range from 280 to 430 °C in order to obtain the best magnetic properties (magnetic saturation Bs and coercivity Hc obtained from the B(H) dependencies) at 50 Hz frequency. For optimal heat-treated samples, the complex magnetic permeability in the frequencies 10
-10
Hz at room temperature was measured. Finally, magnetic core losses were obtained for 1 T/50 Hz and 1.5 T/50 Hz values for samples annealed at T = 310 °C. An analysis of transmission electron microscope images and electron diffraction patterns confirmed that high magnetic parameters are related to the coexistence of the amorphous and nanocrystalline phases.