Microstructure and Magnetic Properties of NdFeB Based Nanocomposites to Shock Compression

Advances in Electronic Packaging, Parts A, B, and C ◽

10.1115/ipack2005-73230 ◽

2005 ◽

Author(s):

Jin-Chein Lin ◽

M. H. Nien ◽

L. C. Chang

Keyword(s):

Magnetic Properties ◽

Shock Compression ◽

Melt Spinning ◽

Magnetic Alloys ◽

Main Work ◽

High Shock ◽

Different Temperatures ◽

Medium Particle ◽

Deformation Processes ◽

Strong Exchange

Three typical Nd-Fe-B permanent magnetic alloys of Nd13Fe75B6Al6, Nd13Fe79B6Si2 and Nd13Fe80B6Zr1 have been presented to study the effect of annealing and shock compression on the microstructure, magnetic and mechanical properties. The response of NdFeB based nanocomposites mixed with medium particle morphologies of Al, Si and Zr, respectively were conducted under high shock pressure. The starting materials were prepared by rapidly quenching and melt-spinning of NdFeB based powders under vacuum at different temperatures. The magnetic properties on Br, Hci and (BH)max tend to increase with rising annealing temperature, and reach their highest value at either 700° or 750°C. The addition of Zr and Si enhance the chemical short range reaction and stablize the residual amorphous matrix. For recovery shock-consolidate compression, Br and Hci reach to a peak value at about 5.5 GPa which can be closely associated with the retention of nanostructure and strong exchange coupling between hard and soft magnetic phases. Secondly, the main work is to experimentally investigate the mechanics of the deformation processes leading to shock-induced chemical reaction. The results showed that the fracture mechanism on three specific magnetic alloys reveal that the Nd13Fe79B6Si2 sample, and the addition of Zr in NdFeB will lead to embrittlement of the ductile morphology.

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Praseodymium and Neodymium-Based Nanocrystalline Hard Magnetic Alloys

MRS Proceedings ◽

10.1557/proc-577-27 ◽

1999 ◽

Vol 577 ◽

Cited By ~ 14

Author(s):

H.A. Davies ◽

C.L. Harland ◽

R.J.I. Betancour ◽

S.G. Mendoza

Keyword(s):

Thermal Stability ◽

Magnetic Properties ◽

Melt Spinning ◽

Experimental Studies ◽

Anisotropy Field ◽

Partial Substitution ◽

Magnetic Alloys ◽

Alloy Systems

ABSTRACTThe magnetic properties of nanophase exchange enhanced RE-Fe-B based alloys ribbons prepared by melt spinning are presented and discussed. The alloy systems investigated include NdyFe94−yB6 and PryFe94−yB6, for y within the range 6-20 at%, and the data are compared in the context of the larger anisotropy field for the Pr2Fe14B phase in comparison with Nd2Fe14B. Experimental studies are also reported for nanophase (Nd-Pr)- Fe-B alloys with various proportions of Nd:Pr, to investigate the increase in coercivity of NdFeB by partial substitution of Nd by Pr, and for (Nd, Pr)-(Fe-Co)-B-based systems, to study the degree to which the remanence enhancement can be maintained for alloys in which Co substitutes for Fe to increase the thermal stability.

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Amorphization, Crystallization, and Magnetic Properties of Melt-Spun SmCo7−x(Cr3C2)x Alloys

Journal of Metallurgy ◽

10.1155/2011/910268 ◽

2011 ◽

Vol 2011 ◽

pp. 1-5

Author(s):

Liya Li ◽

Wei Xie

Keyword(s):

Magnetic Properties ◽

Exchange Coupling ◽

Melt Spinning ◽

Amorphous State ◽

Wheel Surface ◽

Amorphous Phases ◽

Annealed Ribbon ◽

Melt Spun ◽

Interaction Domains ◽

Strong Exchange

Effects of Cr3C2 content and wheel surface speed on the amorphous formation ability and magnetic properties have been investigated for melt-spun SmCo7−x(Cr3C2)x (x=0.10-0.25) alloys. Ribbon melt-spun at lower wheel speed (30 m/s) has composite structure composed of mostly SmCo7, a small amount of Sm2Co17, and residual amorphous phases. The grain size of SmCo7 phase decreases with the increase of Cr3C2 content x. When melt spinning at 40 m/s, SmCo7−x(Cr3C2)x alloys can be obtained in the amorphous state for 0.15≤x≤0.25 with intrinsic coercive Hci of the order of 40–70 Oe. DSC analysis reveals that SmCo7 phase first precipitates from the amorphous matrix at 650∘C, followed by the crystallization of Sm2Co17 phase at 770∘C. Optimal coercivity Hci of 7.98 kOe and remanent magnetization Mr of 55.05 emu/g have been realized in SmCo6.8(Cr3C2)0.20 magnet subjected to melt spinning at 40 m/s and annealing at 650∘C for 5 min. The domain structure of the annealed ribbon is composed of interaction domains typically 100–400 nm in size, which indicates the presence of a strong exchange coupling between the grains.

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Influence of Annealing Temperature on the Magnetic Properties of Rapidly Quenched (Nd,Pr)2-(Fe,Co,Ga,Ti,C)14B/α-Fe Nanocomposite Ribbons

Advances in Materials Science and Engineering ◽

10.1155/2013/620761 ◽

2013 ◽

Vol 2013 ◽

pp. 1-5

Author(s):

Rahim Sabbaghizadeh ◽

Mansor Hashim ◽

Reza Gholamipour ◽

Ghazaleh Bahmanrokh ◽

Mohd Shamsul Ezzad Shafie

Keyword(s):

Magnetic Properties ◽

Melt Spinning ◽

Annealing Temperature ◽

Practical Method ◽

Nominal Composition ◽

Metallic Materials ◽

Scanning Calorimetry ◽

X Ray ◽

Microscopy Technique ◽

Different Temperatures

The effects of different heat treatment temperatures on the structure and magnetic properties of Nd-Fe-B nanocomposite permanent magnetic alloys with nominal composition of Nd9.4Pr0.6Fe74.5Co6B6Ga0.5Ti1.5C1.5have been investigated. The most practical method to produce nanostructured metallic materials is rapid solidification. Melt spinning with constant wheel speed ofV=40 m/s was employed to produce ribbons. As-spun ribbons were examined by using differential scanning calorimetry (DSC) and X-ray diffractometer (XRD) with Cu-kαradiation. The ribbons were annealed at different temperatures in order to extract the best magnetic properties. The XRD and electron microscopy technique results confirm that grains are in the size of less than 50 nm. In addition, optimum magnetic properties were obtained at 700°C annealed temperature.

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Optimum Soft Magnetic Properties of the FeSiBNbCu Alloy Achieved by Heat Treatment and Tailoring B/Si Ratio

Metals ◽

10.3390/met10101297 ◽

2020 ◽

Vol 10 (10) ◽

pp. 1297

Author(s):

Jonghee Han ◽

Seoyeon Kwon ◽

Sungwoo Sohn ◽

Jan Schroers ◽

Haein Choi-Yim

Keyword(s):

Heat Treatment ◽

Magnetic Properties ◽

Melt Spinning ◽

Nanocrystalline Alloys ◽

Soft Magnetic Properties ◽

Vibrating Sample Magnetometer ◽

Soft Magnetic ◽

Different Temperatures ◽

Annealing Heat Treatment ◽

Si Content

To increase the saturation magnetization (Ms) of commercially available soft magnetic Finemet alloys to the level comparable to that of Si-steel and Fe-based nanocrystalline alloys such as Nanoperm, Nanomet, the B or Si content in combination with annealing heat treatment was tailored. The ribbons of Fe95−xSi1BxNb3Cu1 (x = 11, 12, 13) and Fe87−xSixB9Nb3Cu1 (x = 6, 8, 10) were prepared by melt-spinning and annealed at different temperatures to develop nanocrystalline microstructure optimizing the soft magnetic properties. The magnetic properties of the as-spun and annealed ribbons were measured using a vibrating sample magnetometer and AC B-H loop tracer to acquire Ms of above 1.4 T in all as-spun ribbons. Among the alloys, Fe84Si1B11Nb3Cu1 annealed at 545 °C showed the highest Ms of 2 T, which exceeds that of the conventional Finemet and other Fe-based nanocrystalline alloys.

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Influence of Cu on the Improvement of Magnetic Properties and Structure of L10 FePt Nanoparticles

Nanomaterials ◽

10.3390/nano11051097 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1097

Author(s):

Luran Zhang ◽

Xinchen Du ◽

Hongjie Lu ◽

Dandan Gao ◽

Huan Liu ◽

...

Keyword(s):

Magnetic Properties ◽

Annealing Temperature ◽

Reduction Method ◽

Solid Phase ◽

Average Particle Size ◽

Fept Nanoparticles ◽

Average Particle ◽

Phase Reduction ◽

Different Temperatures ◽

One Step

L10 ordered FePt and FePtCu nanoparticles (NPs) with a good dispersion were successfully fabricated by a simple, green, one-step solid-phase reduction method. Fe (acac)3, Pt (acac)2, and CuO as the precursors were dispersed in NaCl and annealed at different temperatures with an H2-containing atmosphere. As the annealing temperature increased, the chemical order parameter (S), average particle size (D), coercivity (Hc), and saturation magnetization (Ms) of FePt and FePtCu NPs increased and the size distribution range of the particles became wider. The ordered degree, D, Hc, and Ms of FePt NPs were greatly improved by adding 5% Cu. The highest S, D, Hc, and Ms were obtained when FePtCu NPs annealed at 750 °C, which were 0.91, 4.87 nm, 12,200 Oe, and 23.38 emu/g, respectively. The structure and magnetic properties of FePt and FePtCu NPs at different annealing temperatures were investigated and the formation mechanism of FePt and FePtCu NPs were discussed in detail.

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