Abstract
In this study, the phase evolution, microstructure and magnetic properties of bulk α-Fe/Nd2Fe14B nanocomposite magnets prepared by a combination of severe plastic deformation (SPD) and thermal annealing have been investigated. Experimental results demonstrate that SPD affects the phase evolution of (Nd,Pr)-Fe-Co-Nb-B alloy upon annealing significantly. The formation of metastable intermediate phases, such as Nd2Fe23B3 and Fe3B, in the alloy has been effectively inhibited as the strain ε is increased to ε = 6.1, yielding a high volume fraction of α-Fe phase (Vc ∼ 37%) in the bulk α-Fe/Nd2Fe14B magnets. The grain size of α-Fe and Nd2Fe14B phases in the magnets decreases with increasing strain. A smaller grain size d = 13.3 nm for α-Fe and 26.5 nm for Nd2Fe14B is achieved at ε = 6.1, and the magnets show the magnetic properties, (BH)max = 14.9 MGOe and Hc = 6.4 kOe, larger than those in the α-Fe/Nd2Fe14B magnets made by directly annealing amorphous ribbons, (BH)max = 10.3 MGOe and Hc = 4.6 kOe. The enhanced coercivity in the SPD magnets results from an increase in domain-wall-pinning strength.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
