Sintered Nd–Fe–B magnets with improved impact stability

Wang, H.J.; Li, A.H.; Zhu, Minggang; Li, W.

doi:10.1016/j.jmmm.2006.04.012

Cited by 28 publications

(2 citation statements)

References 7 publications

(7 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As shown in Figure 4g, 2-14-1 grains with sizes of approximately 300 nm were homogeneously formed in the 12.5 at.% Nd-containing HDDR powders. Because the fracture of Nd-Fe-B alloys occurs along the Nd-rich GBPs [31], the homogeneous morphology of the 2-14-1 grain on the fracture surface directly indicates that uniform and continuous Nd-rich GBPs are formed within the samples [31,32]. Therefore, in the 12.5 at.% Nd-containing HDDR powders, the Nd-rich GBPs are also expected to be uniformly formed.…”

Section: Resultsmentioning

confidence: 99%

Design of High-Remanence Nd-Fe-B Hot-Pressed Magnets by Manipulating Coercivity of Hydrogenation-Disproportionation-Desorption-Recombination Treated Anisotropic Precursors

Yoo,

Kim,

Cha

et al. 2023

Materials

View full text Add to dashboard Cite

We propose a method of manipulating the coercivity of anisotropic hydrogenation-disproportionation-desorption-recombination (HDDR) powders to fabricate high-remanence and fine-grained Nd-Fe-B magnets using only hot-pressing without a subsequent hot-deformation process. By reducing the Nd content of anisotropic HDDR precursors such that their coercivity (Hcj) is lowered, the c-axis of each HDDR particle is well-aligned parallel to the direction of the applied magnetic field during the magnetic alignment step. This is because the magnetic repulsive force between adjacent particles, determined by their remanent magnetization, decreases as a result of the low coercivity of each particle. Therefore, after hot-pressing the low-Hcj HDDR powders, a significantly higher remanence (11.2 kG) is achieved in the bulk than that achieved by hot-pressing the high-Hcj HDDR powders (8.2 kG). It is clearly confirmed by the large-scale electron backscatter diffraction (EBSD) analysis that the alignment of the c-axis of each anisotropic HDDR particle in the bulk is improved when low-Hcj HDDR powders are used to fabricate hot-pressed magnets. This coercivity manipulation of HDDR powders can be a helpful method to expand the use of HDDR powders in fabricating anisotropic Nd-Fe-B bulk magnets.

show abstract

Section: Resultsmentioning

confidence: 99%

Design of High-Remanence Nd-Fe-B Hot-Pressed Magnets by Manipulating Coercivity of Hydrogenation-Disproportionation-Desorption-Recombination Treated Anisotropic Precursors

Yoo,

Kim,

Cha

et al. 2023

Materials

View full text Add to dashboard Cite

show abstract

“…have also been added to Nd-Fe-B magnets to improve their mechanical properties. [95][96][97] A systematic investigation on the effect of metal addition (Al, Ga, Cu, Nb, Zr, Ti, V, Mn, etc.) on the impact toughness has been performed by Liu et al [98] Four ideal metals (Al, Ga, Cu, Nb) were shown to be efficacious in improving impact toughness.…”

Section: Mechanical Properties Of Hd Ndfeb Magnetmentioning

confidence: 99%

Rare earth permanent magnets prepared by hot deformation process

et al. 2018

View full text Add to dashboard Cite

Hot deformation is one of the primary methods for fabricating anisotropic rare earth permanent magnets. Firstly, rapidly quenched powder flakes with a nanocrystal structure are condensed into fully dense isotropic precursors using the hot-pressing process. The prepared isotropic precursors are then hot-deformed to produce high-anisotropy uniaxial bulk rare earth permanent magnets and a highly textured structure is produced via this process. The resulting magnets possess many advantages such as near-net-shape, outstanding corrosion resistance, and ultrafine-grain structure. The influence of the preparation parameters utilized in the hot-pressing and deformation processes on the magnetic properties and microstructure of the permanent magnets are systemically summarized in this report. As a near-net-shape technique, the hot deformation process has notable advantages with regard to the production of irregular shapes, especially for radially oriented ringshaped magnets with high length-diameter ratios or thin walls. The difficulties associated with the fabrication of crack-free, homogeneous, and non-decentered ring-shaped magnets are substantially resolved through an emphasis on mold design, adjustment of deformation parameters, and application of theoretical simulation. Considering the characteristics of hotdeformed magnets which include grain shape and size, anisotropic distribution of intergranular phases, etc., investigation and improvement of the mechanical and electric properties, in addition to thermal stability, with the objective of improving the application of hot-deformed magnets or ring-shaped magnets, is of practical significance.

show abstract