Technology of the Dy Saving for the High-performance Nd-Fe-B Sintered Magnets

元, 中村

doi:10.2320/materia.50.374

Cited by 3 publications

(2 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is a method of incorporating heavy rare earth element (HRE) such as Dy or Tb through the grain boundaries of sintered Nd-Fe-B magnets at elevated temperatures keeping the majority of the Nd 2 Fe 14 B grain intact. This process has been industrially implemented to manufacture high coercive and high remanence Nd-Fe-B based sintered magnets [7]. In this process, Dy is considered to diffuse through grain boundaries (GBs) to form (Nd 1Àx Dy x ) 2 Fe 14 B shells surrounding the Nd 2 Fe 14 B grains [8,9].…”

Section: Introductionmentioning

confidence: 99%

Faceted shell structure in grain boundary diffusion-processed sintered Nd–Fe–B magnets

Seelam

Ohkubo

Abe

et al. 2014

Journal of Alloys and Compounds

View full text Add to dashboard Cite

a b s t r a c tDysprosium enriched shell structure formed by the grain boundary diffusion process (GBDP) of a sintered Nd-Fe-B magnet was characterized by using scanning electron microscopy, electron back-scattered diffraction and transmission electron microscopy. Faceted core-shell interfaces with an abrupt change in Dy concentration suggest the Dy-rich shells are formed by the solidification of the liquid phase during cooling from the GBDP temperature. The Nd-rich phases are almost free from Dy, and their quantity near the surface of a bulk sample is much higher than that in the center, indicating that a higher fraction of a liquid phase exists near the surface during processing at 900°C. These microstructural features are explained on the basis of the phase equilibrium between Nd and Nd 2 Fe 14 B at the processing temperature and subsequent cooling. Based on the results, we discuss the coercivity enhancement by the GBDP using Dy vapor.

show abstract

Section: Introductionmentioning

confidence: 99%

Faceted shell structure in grain boundary diffusion-processed sintered Nd–Fe–B magnets

Seelam

Ohkubo

Abe

et al. 2014

Journal of Alloys and Compounds

View full text Add to dashboard Cite

show abstract

“…This is thought to be due to vacancy diffusion rather than body diffusion (interstitial diffusion), and is a feature of GBD processing that introduces Dy as an oxide. 24) Figure 5(a) presents an SEM-BSE image showing the typical microstructure in the center (ca. 1.0 mm) of the magnet.…”

Section: Resultsmentioning

confidence: 99%

Elemental Distribution near the Grain Boundary in a Nd–Fe–B Sintered Magnet Subjected to Grain-Boundary Diffusion with Dy<sub>2</sub>O<sub>3</sub>

et al. 2020

View full text Add to dashboard Cite

We have investigated the microstructure in a NdFeB sintered magnet subjected to the grain-boundary diffusion (GBD) process with Dy 2 O 3 . It was found that thin (Nd,Dy) 2 Fe 14 B shells with a thickness of at least 10 nm and an average Dy concentration of approximately 0.7 at% were formed even at the center of the specimen, at a depth of approximately 1 mm from the specimen surface. However, the area fraction of the fcc NdO phase remained almost constant at approximately 3% throughout the magnet irrespective of depth, and the grain-boundary wetting phase hardly changed except in the vicinity of the surface. Furthermore, the thickness (ca. 3 nm) and structure (amorphous) of the thin grain boundary phase existing between Nd 2 Fe 14 B grains remained almost unchanged by the Dy-GBD process, despite the formation of the coreshell structure. Therefore, the Dy concentration in the thin Dy-substituted shell is important for improving the coercivity via the GBD process.

show abstract

Coercivity saturation in Nd-Fe-B sintered magnets treated by grain boundary diffusion process of Tb-Ni-Al alloy

Itakura,

Kontani,

Akamine

et al. 2023

Journal of Magnetism and Magnetic Materials

View full text Add to dashboard Cite

Technology of the Dy Saving for the High-performance Nd-Fe-B Sintered Magnets

Cited by 3 publications

References 3 publications

Faceted shell structure in grain boundary diffusion-processed sintered Nd–Fe–B magnets

Faceted shell structure in grain boundary diffusion-processed sintered Nd–Fe–B magnets

Elemental Distribution near the Grain Boundary in a Nd–Fe–B Sintered Magnet Subjected to Grain-Boundary Diffusion with Dy<sub>2</sub>O<sub>3</sub>

Coercivity saturation in Nd-Fe-B sintered magnets treated by grain boundary diffusion process of Tb-Ni-Al alloy

Contact Info

Product

Resources

About