Hard magnetic properties of anisotropic Sm–Fe–N magnets produced by compression shearing method

Saito, Tetsuji; Kitazima, Hiroshi

doi:10.1016/j.jmmm.2011.03.022

Cited by 22 publications

(6 citation statements)

References 15 publications

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“…Furthermore, in this study, because die compaction was combined with HVC, the dimensional precision of the fabricated magnets was high (within «0.02 mm for both thickness and width under constant conditions). Such high dimensional precision is a characteristic of die compaction and is difficult to achieve using an explosive method, 22) compression shearing, 23) or swaging, 12) which have been reported for the compaction of SmFeN.…”

Section: Resultsmentioning

confidence: 99%

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Fabrication of High-Density Zn-Bonded Sm–Fe–N Bulk Magnets via High-Velocity Compaction

et al. 2021

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High-velocity compaction (HVC) using a die was investigated as a compaction technique for the fabrication of high-density isotropic Znbonded SmFeN bulk magnets. The compaction characteristics of Zn-mixed SmFeN powders obtained by HVC were investigated while varying the Zn content. Moreover, the magnetic properties, flexural strengths (•), and microstructures of the resulting magnets were studied. The relative density (d r ) steadily increased with the piston velocity during compaction and reached approximately 90% at a piston velocity of 11.2 m•s ¹1 (equivalent to a compaction pressure of 3.45 GPa), regardless of the Zn content. Because the magnets were fabricated using a die, they also had a high dimensional precision. The resulting magnet, with 5 wt% Zn and d r of 89.1%, exhibited a maximum energy product ((BH ) Max ) of 54.4 kJ•m ¹3 , remanence (B r ) of 0.56 T, and coercivity (H cJ ) of 965 kA•m ¹1 . • exceeded 100 MPa when d r was above 88%, which satisfies the required mechanical strength for applications such as permanent magnet motors.

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Section: Resultsmentioning

confidence: 99%

“…The densification of SmFeN has been achieved through the explosive shock-compression method, 22) which is a typical HVC method. Furthermore, swaging 12) and compression shearing 23) have been reported as techniques based on a concept similar to the HVC. The resulting magnets had relative densities (d r ) above 90% or 95%.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of High-Density Zn-Bonded Sm–Fe–N Bulk Magnets via High-Velocity Compaction

et al. 2021

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“…Prototype bulk magnets using non-heat forming processes such as shear compression (Saito T. et al, 2005;Saito T. and Kitazima H., 2011; and shock consolidation (Mashimo T. et al, 2000;Mashimo T. et al, 1999) have been reported, and recently, the authors also conducted research that refocuses on powder rolling (Hosokawa A. et al, 2021b). A method called high-pressure torsion processing has also attracted attention in recent years (Edalati K. and Horita Z., 2016;Valiev R.Z.…”

Section: Low-thermal Load Consolidationmentioning

confidence: 99%

Recent Research Trend in Powder Process Technology for High-Performance Rare-Earth Permanent Magnets

Takagi

Hirayama

Okada

et al. 2023

KONA

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Higher performance is constantly required in rare earth permanent magnets, which are an indispensable component of the motors of electric vehicles. When producing sintered magnets, advanced structural control is necessary in the powder metallurgy process in order to achieve high performance. Especially in recent years, it has become important to develop processes for Sm-Fe-N magnets and metastable phase magnets as next-generation magnets to replace the Nd-Fe-B magnets. Because the crystal grain refinement of sintered magnets is most effective for improving coercivity, production methods for raw powders have evolved from the traditional pulverization to chemical synthesis approaches, and as a result, a submicron-sized Sm-Fe-N powder with huge coercivity has been developed. State-ofthe-art physical synthesis methods have also been applied successfully to the synthesis of nanopowders. Since control of the grain boundary is very effective in Nd-Fe-B magnets, this approach has also been evolved to Sm-Fe-N magnets by nano coating. On the other hand, since technologies for crystalline orientation control and high-density sintering are indispensable for improvement of remanence, new low-thermal load consolidation techniques such as spark plasma sintering are being developed for Sm-Fe-N magnets and metastable phase magnets in order to overcome the inherent low thermal stability of these materials.

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“…One approach to preparing Sm 2 Fe 17 N 3 -based bulk magnets is to apply high pressure, such as by pressing with high pressure [ 65 ] and shock compression [ 66 ]. Saito and Kitazima [ 67 ] reported high (BH) max of 228 kJm −3 by using a compression shearing method. The AIST group [ 65 , 68 , 69 ] applied a high sintering pressure to fabricate binder-free Sm-Fe-N magnets, and Takagi et al [ 69 ] reported Sm-Fe-N bulk magnet showing good (BH) max of 196 kJm −3 (=24.5 MGOe).…”

Section: Development Of High-performance Zn-bonded Sm-fe-n Magnetsmentioning

confidence: 99%

Recent progress in the development of high-performance bonded magnets using rare earth–Fe compounds

Horikawa

Yamazaki

Matsuura

et al. 2021

Science and Technology of Advanced Materials

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Permanent magnets, and particularly rare earth magnets such as Nd-Fe-B, have attracted much attention because of their magnetic properties. There are two wellestablished techniques for obtaining sintered magnets and bonded Nd-Fe-B magnets. Powder metallurgy is used to obtain high-performance anisotropic sintered magnets. To produce bonded magnets, either melt-spinning or the hydrogenation, disproportionation, desorption, and recombination process is used to produce magnet powders, which are then mixed with binders. Since the development of Nd-Fe-B magnets, several kinds of intermetallic compounds have been reported, such as Sm 2 Fe 17 N x and Sm(Fe,M) 12 (M: Ti, V, etc.). However, it is difficult to apply a liquid-phase sintering process similar to the one used for Nd-Fe-B sintered magnets in order to produce high-performance Sm-Fe-based sintered magnets because of the low decomposition temperature of the compound and the lack of a liquid grain boundary phase like that in the Nd-Fe-B system.Therefore, bonded magnets are useful in the production of bulk magnets using these Sm-Fe based compounds. This article reviews recent progress in our work on the development of high-performance bonded magnets using Nd 2 Fe 14 B and Sm 2 Fe 17 N x compounds.

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Hard magnetic properties of anisotropic Sm–Fe–N magnets produced by compression shearing method

Cited by 22 publications

References 15 publications

Fabrication of High-Density Zn-Bonded Sm–Fe–N Bulk Magnets via High-Velocity Compaction

Fabrication of High-Density Zn-Bonded Sm–Fe–N Bulk Magnets via High-Velocity Compaction

Recent Research Trend in Powder Process Technology for High-Performance Rare-Earth Permanent Magnets

Recent progress in the development of high-performance bonded magnets using rare earth–Fe compounds

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