Improving exchange-spring nanocomposite permanent magnets

2004 ◽  
Vol 85 (22) ◽  
pp. 5293-5295 ◽  
Author(s):  
J. S. Jiang ◽  
J. E. Pearson ◽  
Z. Y. Liu ◽  
B. Kabius ◽  
S. Trasobares ◽  
...  
Keyword(s):  
Permanent Magnets ◽  
Exchange Spring

scholarly journals Cluster-assembled exchange-spring nanocomposite permanent magnets

2005 ◽  
Vol 97 (10) ◽  
pp. 10K310 ◽  
Author(s):  
X. Rui ◽  
Z. G. Sun ◽  
Y. Xu ◽  
D. J. Sellmyer ◽  
J. E. Shield
Keyword(s):  
Permanent Magnets ◽  
Exchange Spring

Physical Properties of Bonded Nanocomposite Type Hard-Soft Magnets

2011 ◽  
Vol 672 ◽  
pp. 84-87
Author(s):  
Eugen Dorolti ◽  
Alex Todoran ◽  
Maria Simona Gutoiu ◽  
Albert Flavius Takacs ◽  
Ionel Chicinaş ◽  
...  
Keyword(s):  
Composite Material ◽  
Magnetic Fields ◽  
Physical Properties ◽  
Mechanical Milling ◽  
Permanent Magnets ◽  
Magnetic Characteristics ◽  
Magnetic Powder ◽  
Processing Conditions ◽  
Soft Magnets ◽  
Exchange Spring

The exchange spring magnetic powders of SmCo5/α-Fe were obtained by mechanical milling and annealing. SmCo5+20 wt% α-Fe powder milled for 8 h and annealed at about 550 °C was considered to be more appropriate for our purpose. The isotropic nanocomposite permanent magnets were obtained by bonding the magnet powder in a binder matrix. Several ratios from 0.5 to 1.5 wt % between binder and magnetic powder were used. The composite material was compacted in dies at pressure from 600 to 800 MPa. The heat treatments for polymerisation were performed at 180 °C for 1h. The density and the microstructure of the magnets are discussed in connection with the properties of the starting powder and processing conditions. Magnetic characteristics of Br, Hc and (BH)max were obtained from hysteresis curves in magnetic fields up to 10 T.

Experimental and micromagnetic first-order reversal curves analysis in NdFeB-based bulk “exchange spring”-type permanent magnets

2007 ◽  
Vol 316 (2) ◽  
pp. 177-180 ◽  
Author(s):  
Horia Chiriac ◽  
Nicoleta Lupu ◽  
Laurentiu Stoleriu ◽  
Petronel Postolache ◽  
Alexandru Stancu
Keyword(s):  
Permanent Magnets ◽  
First Order ◽  
Exchange Spring ◽  
Spring Type

scholarly journals Magnetic reversal in three-dimensional exchange-spring permanent magnets

2006 ◽  
Vol 99 (8) ◽  
pp. 08B508 ◽  
Author(s):  
J. E. Shield ◽  
J. Zhou ◽  
S. Aich ◽  
V. K. Ravindran ◽  
R. Skomski ◽  
...  
Keyword(s):  
Permanent Magnets ◽  
Three Dimensional ◽  
Magnetic Reversal ◽  
Exchange Spring

scholarly journals High-energy product exchange-spring FePt/Fe cluster nanocomposite permanent magnets

2006 ◽  
Vol 305 (1) ◽  
pp. 76-82 ◽  
Author(s):  
X. Rui ◽  
J.E. Shield ◽  
Z. Sun ◽  
L. Yue ◽  
Y. Xu ◽  
...  
Keyword(s):  
Permanent Magnets ◽  
High Energy ◽  
Energy Product ◽  
Exchange Spring

Optimizing the magnetic properties of hard and soft materials for producing exchange spring permanent magnets.

2020 ◽  
Author(s):  
Michele Petrecca ◽  
Beatrice Muzzi ◽  
Stefano Olivieri ◽  
Martin Albino ◽  
Nader Yaacoub ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Permanent Magnets ◽  
Soft Materials ◽  
Exchange Spring

EM of rapidly solidified permanent magnets

1992 ◽  
Vol 50 (1) ◽  
pp. 198-199
Author(s):  
Raja K. Mishra
Keyword(s):  
Melt Spinning ◽  
Permanent Magnets ◽  
Dark Field Image ◽  
Dark Field ◽  
Maximum Energy ◽  
Quench Rate ◽  
Maximum Energy Product ◽  
Energy Product ◽  
Annular Dark Field ◽  
Rapidly Solidified

The discovery of a new class of permanent magnets based on Nd2Fe14B phase in the last decade has led to intense research and development efforts aimed at commercial exploitation of the new alloy. The material can be prepared either by rapid solidification or by powder metallurgy techniques and the resulting microstructures are very different. This paper details the microstructure of Nd-Fe-B magnets produced by melt-spinning.In melt spinning, quench rate can be varied easily by changing the rate of rotation of the quench wheel. There is an optimum quench rate when the material shows maximum magnetic hardening. For faster or slower quench rates, both coercivity and maximum energy product of the material fall off. These results can be directly related to the changes in the microstructure of the melt-spun ribbon as a function of quench rate. Figure 1 shows the microstructure of (a) an overquenched and (b) an optimally quenched ribbon. In Fig. 1(a), the material is nearly amorphous, with small nuclei of Nd2Fe14B grains visible and in Fig. 1(b) the microstructure consists of equiaxed Nd2Fe14B grains surrounded by a thin noncrystalline Nd-rich phase. Fig. 1(c) shows an annular dark field image of the intergranular phase. Nd enrichment in this phase is shown in the EDX spectra in Fig. 2.

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