The hard magnetic properties of nanocomposite Nd3.6Pr5.4Fe83Co3B5 ribbons prepared by melt spinning

2007 ◽

Author(s):

Zongjun Tian ◽

Shangdong Li ◽

Youwei Du ◽

Yinhui Huang

Keyword(s):

Magnetic Properties ◽

Hysteresis Loop ◽

Grain Boundaries ◽

Exchange Coupling ◽

Melt Spinning ◽

Permanent Magnets ◽

Energy Product ◽

Remanence Ratio ◽

Optimum Energy ◽

Hard Magnetic Properties

The effect of indium additions on the microstructures and magnetic properties of Nd9Fe85−xB6Inx (x = 0–2) nanocomposites prepared by melt spinning was investigated. It was found that a certain amount of indium added to Nd9Fe85B6 magnets enhances the hard magnetic properties. The coercivity and remanence ratio of the magnet with 0.5 at.% indium increases from 405kA/m (no indium) to 465kA/m and from 0.7 to 0.86 respectively. Squareness of its hysteresis loop is also improved greatly. The optimum energy product (BH)max increases remarkably from 95kJ/m3 to 145kJ/m3. The origin for those enhancements is mainly attributed to the magnetically softened grain boundaries and enhanced crystallographical coherency by indium addition. The magnetic annealing is found to be helpful to enhance the coherency and coupling between hard and soft phases.

Download Full-text

Microstructure and hard magnetic properties of directly synthesized L10(Fe1−xPtx)78Zr4B18 nanocrystalline alloys by melt spinning

Journal of Applied Physics ◽

10.1063/1.1853252 ◽

2005 ◽

Vol 97 (10) ◽

pp. 10H307 ◽

Cited By ~ 10

Author(s):

T. Bitoh ◽

A. Makino ◽

M. Nakagawa

Keyword(s):

Magnetic Properties ◽

Melt Spinning ◽

Nanocrystalline Alloys ◽

Hard Magnetic Properties

Download Full-text

Effect of Preparation on Glass Formation and Magnetic Properties of Nd-Fe-Co-Al-B Alloys

MRS Proceedings ◽

10.1557/proc-644-l12.14 ◽

2000 ◽

Vol 644 ◽

Author(s):

G. Kumar ◽

J. Eckert ◽

L.Q. Xing ◽

A. Güth ◽

S. Roth ◽

...

Keyword(s):

Magnetic Properties ◽

Melt Spinning ◽

Hysteresis Loops ◽

Liquid Region ◽

Atomic Order ◽

Copper Mold ◽

Mechanically Alloyed ◽

Copper Mold Casting ◽

Mold Casting ◽

Hard Magnetic Properties

AbstractThe effect of alternative preparation methods (copper mold casting, melt spinning, and mechanical attrition) on amorphization and properties of Nd57Fe20Co5Al10B8 and Nd40Fe40Co5Al8B7 alloys has been investigated. For all differently prepared samples an amorphous phase is formed upon solidification or solid sate reaction. However, the samples prepared by different processing routes exhibit different transformation behavior in thermal analysis. The cast Nd57Fe20Co5Al10B8 rod exhibits crystallization at 790 K followed by melting at 810 K. Neither appreciable endothermic reaction due to a glass transition nor a supercooled liquid region have been observed. Mechanically alloyed powders and ball-milled prealloys reveal two exothermic DSC peaks in the range of 650-850 K. The J-H hysteresis loops of samples synthesized by different routes show that the unique atomic order responsible for hard magnetic properties can only be accessed at moderate cooling rate of the melt as realized in copper mold casting. Rapidly quenched ribbons, mechanically alloyed powders and ball-milled ingots do not show hard magnetic properties at room temperature. These results indicate that amorphous samples with different local atomic order can be prepared by different processing routes.

Download Full-text

Microstructure and hard magnetic properties of nanocomposite Sm2Fe15Ga2Cx permanent magnets with an excess of Fe prepared directly by melt spinning

Applied Physics Letters ◽

10.1063/1.120939 ◽

1998 ◽

Vol 72 (9) ◽

pp. 1110-1112 ◽

Cited By ~ 18

Author(s):

Zhao-hua Cheng ◽

Jun-xian Zhang ◽

Hui-qun Guo ◽

J. van Lier ◽

H. Kronmüller ◽

...

Keyword(s):

Magnetic Properties ◽

Melt Spinning ◽

Permanent Magnets ◽

Hard Magnetic Properties

Download Full-text

Improved thermal stability of hard magnetic properties in rapidly solidified RE–TM–B alloys

Journal of Materials Research ◽

10.1557/jmr.2008.0337 ◽

2008 ◽

Vol 23 (10) ◽

pp. 2733-2742 ◽

Cited By ~ 10

Author(s):

Z.W. Liu ◽

R.V. Ramanujan ◽

H.A. Davies

Keyword(s):

Thermal Stability ◽

Grain Size ◽

Magnetic Properties ◽

Elevated Temperature ◽

Melt Spinning ◽

Maximum Energy ◽

Maximum Energy Product ◽

Energy Product ◽

Rapidly Solidified ◽

Hard Magnetic Properties

Rapidly solidified nanocrystalline RE–TM–B (RE = Nd, Pr, Dy, TM = Fe, Co) alloys with enhanced hard magnetic properties were synthesized by melt spinning. The composition- and microstructure-dependent elevated temperature magnetic properties were investigated. The temperature coefficients of remanence (α) and coercivity (β) were determined. The effects of Pr substituting Nd, Co substituting Fe, Dy substituting RE, and grain size on the Curie temperature and thermal stability were studied. Co or Dy substitutions were found to have a significant beneficial effect on the thermal stability. Reducing grain size could also improve elevated temperature behavior. Maximum energy product (BH)max > 100 kJ/m3 could be obtained in compositionally optimized nanophase alloys at temperature of 473 K. Extremely low coefficients of α and β were realized in exchange coupled nanocomposite alloys. Bonded nanocomposite magnets with α = −0.052%/K and β = −0.0365%/K for 300–400 K were also successfully fabricated.

Download Full-text

Influence Of Cooling Rate On Phase Composition And Magnetic Properties Of Sm12.5Co66.5Fe8Cu11Si2 Alloy In The Form Of Ribbon In As-Quenched State

Archives of Metallurgy and Materials ◽

10.1515/amm-2015-0190 ◽

2015 ◽

Vol 60 (2) ◽

pp. 667-670

Author(s):

M. Dośpiał ◽

M. Nabiałek ◽

K. Błoch

Keyword(s):

Magnetic Field ◽

Magnetic Properties ◽

Melt Spinning ◽

Magnetic Measurements ◽

Rapid Quenching ◽

Vibrating Sample Magnetometer ◽

Fabrication Method ◽

Entire Volume ◽

Diffraction Patterns ◽

Hard Magnetic Properties

Abstract The fabrication method and magnetic properties of Sm12.5Co66.5Fe8Cu11Si2 alloy are presented in this article. The samples were produced by rapid quenching of the liquid alloy onto a rotating, copper wheel (the so-called ‘melt-spinning’ method) and they had a thin ribbon shape. The microstructure of the samples was investigated by measurements of diffraction patterns for powdered samples, in order to obtain data from the entire volume of the sample. It was found, that samples were composed of different amounts of Sm2Co17, SmCo5 and SmCo7 phases, depending on the linear velocity of the copper wheel used during the fabrication process. The magnetic measurements were performed using a vibrating sample magnetometer (LakeShore VSM) working with an external magnetic field of up to 2 T. It was found that the obtained ribbons displayed relatively good hard magnetic properties, such as remanence μ0MR, and high resistance to demagnetization fields JHC.

Download Full-text