High coercivity in rare-earth lean nanocomposite magnets by grain boundary infiltration

Madugundo, Rajasekhar; Salazar-Jaramillo, Daniel; Barandiarán, J.M.; Hadjipanayis, G. C.

doi:10.1016/j.jmmm.2015.07.019

Cited by 12 publications

(5 citation statements)

References 13 publications

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“…In [126], magnets based on NdFeB were fabricated by BJ followed by sintering and infiltration by nonmagnetic eutectic Nd 3 Cu 0.25 Co 0.75 and Pr 3 Cu 0.25 Co 0.75 alloys. These compositions were selected not only due to their low melting points but also due their ability to significantly increase the internal coercivity of magnets based on NdFeB [129][130][131]. It is generally believed that a thick interlayer of the phase enriched with rare earth elements and depleted in Fe is necessary for weakening the exchange coupling between the grains of the Nd 2 Fe 14 B phase, which leads to an increased coercivity.…”

Section: Binder Jettingmentioning

confidence: 99%

3D Printing Technologies for Fabrication of Magnetic Materials Based on Metal–Polymer Composites: A Review

Mazeeva,

Masaylo,

Razumov

et al. 2023

Materials

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Additive manufacturing is a very rapidly developing industrial field. It opens many possibilities for the fast fabrication of complex-shaped products and devices, including functional materials and smart structures. This paper presents an overview of polymer 3D printing technologies currently used to produce magnetic materials and devices based on them. Technologies such as filament-fused modeling (FDM), direct ink writing (DIW), stereolithography (SLA), and binder jetting (BJ) are discussed. Their technological features, such as the optimal concentration of the filler, the shape and size of the filler particles, printing modes, etc., are considered to obtain bulk products with a high degree of detail and with a high level of magnetic properties. The polymer 3D technologies are compared with conventional technologies for manufacturing polymer-bonded magnets and with metal 3D technologies. This paper shows prospective areas of application of 3D polymer technologies for fabricating the magnetic elements of complex shapes, such as shim elements with an optimized shape and topology; advanced transformer cores; sensors; and, in particular, the fabrication of soft robots with a fast response to magnetic stimuli and composites based on smart fillers.

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Section: Binder Jettingmentioning

confidence: 99%

3D Printing Technologies for Fabrication of Magnetic Materials Based on Metal–Polymer Composites: A Review

Mazeeva,

Masaylo,

Razumov

et al. 2023

Materials

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“…In this case, the grain boundary infiltration differs from grain boundary diffusion in the fact that the passing alloy is liquid [12]. It was shown experimentally that to realize infiltration in permanent magnets and rapidly quenched Nd-Fe-B alloys, alloys comprising a rare-earth metal, copper, and, sometimes another 3d-metal can be used [13][14][15]. In [14], the grain boundary infiltration was performed after additive manufacturing of magnets, whereas in [16], the record coercivity of printer magnets was achieved in the absence of post-processing and heavy rare-earth metals.…”

Section: Introductionmentioning

confidence: 99%

The Magnetic Properties of a NdFeB Permanent Magnets Prepared by Selective Laser Sintering

Maltseva

Андреев

Neznakhin

et al. 2022

Phys. Metals Metallogr.

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Abstract—The additive manufacturing of functional materials has a number of advantages over the sintering, which consist in the possibility of fabricating near-net-shape and locally forming the properties. In the present study, the effect of synthesis parameters on the phase composition and magnetic hysteretic properties of single-layer Nd2Fe14B-based permanent magnets synthesized by selective laser sintering is investigated. The causes for the effect of synthesis parameters on the magnetic hysteretic properties are considered. The possibility of reaching a coercivity of single-layer magnets of 19.5 kOe, which are free of heavy rare-earth metals, is demonstrated.

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“…However, both Dy and Tb are critical and strategic raw materials [1], and the recent rare-earth crisis calls for rare-earth-lean or rareearth-free permanent magnets. Melt-spun Nd-lean Nd-Fe-B alloys are potential candidates for the development of nanocomposite magnets consisting of magnetically hard Nd 2 Fe 14 B grains exchange-coupled with magnetically soft α-Fe grains [2]. Usually, the coercivity of these magnets is rather low, but could be enhanced substantially with grain-boundary infiltration [2].…”

Section: Introductionmentioning

confidence: 99%

“…Melt-spun Nd-lean Nd-Fe-B alloys are potential candidates for the development of nanocomposite magnets consisting of magnetically hard Nd 2 Fe 14 B grains exchange-coupled with magnetically soft α-Fe grains [2]. Usually, the coercivity of these magnets is rather low, but could be enhanced substantially with grain-boundary infiltration [2]. Therefore, it is very important to gain a better understanding of the crystallization processes and the final microstructure in melt-spun Nd-Fe-B alloys before infiltration [2,3].…”

Section: Introductionmentioning

confidence: 99%

“…Usually, the coercivity of these magnets is rather low, but could be enhanced substantially with grain-boundary infiltration [2]. Therefore, it is very important to gain a better understanding of the crystallization processes and the final microstructure in melt-spun Nd-Fe-B alloys before infiltration [2,3]. In this sense, many researchers have been working to identify the best fabrication conditions to obtain exchangecoupled nanocomposite Nd-Fe-B-based permanent magnets [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

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Effect of Nb and Cu on the crystallization behavior of under-stoichiometric Nd–Fe–B alloys

Salazar¹,

Martín-Cid²,

Madugundo³

et al. 2016

J. Phys. D: Appl. Phys.

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In this work, we present a complete study of the influence of Nb and Cu addition on the crystallization behavior of Nd-lean Nd-Fe-B melt-spun alloys. Alloys with compositions Nd 10−x−y Fe 84 B 6 Nb x Cu y (x = 1, y = 0 and x = 0.5, y = 0.5) were melt-spun at different wheel speeds (15-40 m s −1) to obtain samples in amorphous, highly disordered and nanocrystalline structures. The crystallization process, induced by different heat treatments, was studied by means of differential thermal analysis and x-ray powder thermodiffraction. Magnetic properties of as-made and heat-treated ribbons were measured by magnetometry. The as-made amorphous samples showed a crystallization to the 2:14:1 hard magnetic phase at T 1 ~ 350 °C. Doping with Nb results in an increase of T 1 , and addition of Cu lowers T 1. This behavior is explained in terms of an inhibition of grain growth by Nb and a nucleation enhancement by Cu additions. During the crystallization process, a secondary phase (identified as a bcc-Fe-rich phase) is formed. The amount of such a phase increases with the annealing temperature. Coercivity increases upon annealing reaching maxima at 700-750 °C. This can be explained in terms of competition between the two phases formed: the 2:14:1 hard phase and the soft bcc-Fe-rich phase. The highest coercivity of the Nd-lean samples is observed when the microstructure is appropriate and both phases are exchange-coupled.

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High coercivity in rare-earth lean nanocomposite magnets by grain boundary infiltration

Cited by 12 publications

References 13 publications

3D Printing Technologies for Fabrication of Magnetic Materials Based on Metal–Polymer Composites: A Review

3D Printing Technologies for Fabrication of Magnetic Materials Based on Metal–Polymer Composites: A Review

The Magnetic Properties of a NdFeB Permanent Magnets Prepared by Selective Laser Sintering

Effect of Nb and Cu on the crystallization behavior of under-stoichiometric Nd–Fe–B alloys

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