Abstract
Bulk dense anisotropic rare earth (RE)-Fe-B magnets synthesized by hot pressing and subsequent hot deforming melt-spun powders have attracted much attention because of their good all-around properties. It is well known that the formation of the desired crystallographic texture is critical to obtain good magnetic properties in the preparation process of anisotropic RE-Fe-B magnets. Melt-spun ribbons with nominal compositions of Nd <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">13</sub> Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">78</sub> Co <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> B <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> and Ce <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sub> Cu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> were consolidated into isotropic nanocrystalline NdFeB hot-pressed magnets by the spark plasma sintering technique, and the microstructure and magnetic properties of the magnets were investigated. Results demonstrate that the coercivity of the magnets is enhanced dramatically by the grain boundary diffusion of the low-melting-point CeCu alloy. With 10 wt% CeCu addition, the coercivity increases from 7.5 to 12.44 kOe. The excessive CeCu, however, reduces the remanence of the NdFeB magnets from 7.76 to 5.66 kGs. Moreover, an appropriate holding time effectively improves the magnetic properties of the magnets. The microstructure indicates that the main phase NdFeB with a grain thickness of 20 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> , and the rest are Nd-rich phase and CeCu grain boundary phase. The intergranular phase of CeCu acts as a diffusion channel, which improves the diffusion efficiency and the uniform distribution of elements. The magnets sintered by spark plasma form a special two-zone structure with a coarse grain region and a fine grain region, and the CeCu alloy effectively inhibits the growth of the grains.
Accepted Version
Published Version
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.
