Influence of wheel speed during planar flow melt spinning on the microstructure and soft magnetic properties of Fe68.5Si18.5B9Nb3Cu1 ribbons

• Published in: Journal of materials science Vol. 46; no. 3; pp. 616 - 622
• Main Authors: Srinivas, M., Majumdar, B., Akhtar, D., Srivastava, A. P., Srivastava, D.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.02.2011; Springer Nature B.V
• Subjects: Annealing; Braking systems; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Coercivity; Crystal defects; Crystallization; Crystallography and Scattering Methods; Enthalpy; Magnetic permeability; Magnetic properties; Magnetic saturation; Magnetism; Materials Science; Melt spinning; Microstructure; Nanocrystals; Polymer Sciences; Positron lifetime spectroscopy; Ribbons; Scanning electron microscopy; Solid Mechanics; Spectrum analysis; Transmission electron microscopy; Volume fraction; Wheels; Amorphous Phase; Amorphous Matrix; Wheel Speed; Saturation Magnetization; Positron Lifetime
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-010-4770-3

The structure and soft magnetic properties of Fe 68.5 Si 18.5 B 9 Nb 3 Cu 1 (at.%) alloy ribbons produced through planar flow melt spinning at different wheel speeds viz. 34, 17 and 12 m/s have been investigated using X-ray diffraction, differential scanning calorimetry, transmission electron microscopy, vibrating sample magnetometer and positron lifetime spectroscopy. Amorphous ribbons formed with different wheel speeds manifested different enthalpy and activation energy of crystallization. The volume fraction of nanocrystalline phase, saturation magnetization and permeability are found to increase whereas coercivity is found to decrease with increasing wheel speed on annealing. A detailed analysis of positron lifetime spectra obtained from the as-spun ribbons has been used to rationalize the variation in microstructure and magnetic properties. The presence of larger number of defects at higher wheel speed increases the volume fraction of nanocrystalline phase on annealing which improves the soft magnetic properties.