Developments in the processing and properties of NdFeb-type permanent magnets

Brown, David Norvil; Ma, B.M.; Chen, Zhongmin

doi:10.1016/s0304-8853(02)00334-7

Cited by 385 publications

(149 citation statements)

References 9 publications

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“…However, sintered magnets with complex net geometry are difficult to produce with traditional manufacturing techniques; pressing tools are only available for a limited number of shapes and the mechanical stability and the large shrinkage of the green bodies upon sintering (up to 25 vol%) are additional challenges for realizing net shape structures. Machining after sintering is also difficult, as the materials are brittle and prone to cracking . A number of alternative methods for complex net shape magnets have been tested to date.…”

Section: Introductionmentioning

confidence: 99%

Net Shape 3D Printed NdFeB Permanent Magnet

et al. 2017

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Section: Introductionmentioning

confidence: 99%

Net Shape 3D Printed NdFeB Permanent Magnet

et al. 2017

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“…NdFeB powder for polymer bonded magnets can be produces by a melt spinning process. This produces ribbons or flakes with a size about 200 µm [4,5]. Inert gas atomization processes produce spherical powder with a particle size of approximately 45 µm [6], which is usually preferred in injection molding processes to achieve better rheological behavior.…”

Section: Introductionmentioning

confidence: 99%

3D print of polymer bonded rare-earth magnets, and 3D magnetic field scanning with an end-user 3D printer

Huber

Abert

Bruckner

et al. 2016

Applied Physics Letters

180

121

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3D print is a recently developed technique, for single-unit production, and for structures that have been impossible to build previously. The current work presents a method to 3D print polymer bonded isotropic hard magnets with a low-cost, end-user 3D printer. Commercially available isotropic NdFeB powder inside a PA11 matrix is characterized, and prepared for the printing process. An example of a printed magnet with a complex shape that was designed to generate a specific stray field is presented, and compared with finite element simulation solving the macroscopic Maxwell equations. For magnetic characterization, and comparing 3D printed structures with injection molded parts, hysteresis measurements are performed. To measure the stray field outside the magnet, the printer is upgraded to a 3D magnetic flux density measurement system. To skip an elaborate adjusting of the sensor, a simulation is used to calibrate the angles, sensitivity, and the offset of the sensor. With this setup a measurement resolution of 0.05 mm along the z-axes is achievable. The effectiveness of our novel calibration method is shown.With our setup we are able to print polymer bonded magnetic systems with the freedom of having a specific complex shape with locally tailored magnetic properties. The 3D scanning setup is easy to mount, and with our calibration method we are able to get accurate measuring results of the stray field.

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“…Commercial melt-spun Nd13.5Fe73.8Ga0.4Co6.7B5.6 powders (Magnequench Neo Powders MQU-F1) [13] were subjected to pressing on an ECAP facility at 723 K and 823 K; the back pressure was altered systematically at 823 K. Unlike dieupsetting, our process is single-step where pre-compaction is unnecessary. In addition, the same sample was pressed twice subsequently through the route A and C (described below) at 823 K with a constant backward pressure (BP) of 0.5 GPa.…”

Section: Methodsmentioning

confidence: 99%

Effect of Processing Parameters on the Magnetic Properties and Macrotexture of a Nd_13.5Fe_73.8Co_6.7B_5.6Ga_0.4Alloy Processed by Equal Channel Angular Pressing With Back Pressure

et al. 2016

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Equal channel angular pressing (ECAP) is a well-established thermo-mechanical processing technique which could induce c-axis texture of Nd2Fe14B in a melt-spun Nd13.5Fe73.8Co6.7B5.6Ga0.4 alloy. However, the effects of ECAP processing parameters such as temperature, backward-pressure and multiple-pass ECAP routes remain unknown for this alloy. In this work we have investigated the effects of these processing parameters on the c-axis texture formation. It is found by xray diffraction macrotexture analysis that the maximum intensity of 001 pole figures for the tetragonal-Nd2Fe14B phase (Imax) shows an increase from 2.7 to 4.1 m.r.d. (multiples of random distribution) by increasing the ECAP temperature from 723 to 823 K, while the difference in remanent magnetization between easy and hard directions (ΔMr ) rises from 24.0 Am 2 /kg to 41.5 Am 2 /kg. When the back-pressure was increased from 0.25 to 0.5 GPa at 823 K, Imax showed an increase from 2.8 to 4.1 m.r.d. However, Imax saturated for back-pressures above 0.5 GPa, suggesting that back pressure has limited effect on the texture formation, although it is necessary for compaction of the alloy powders. Two multiple-pass ECAP routes conventionally known as route-A and -C were employed for two-pass ECAP at 823 K. It is found that the route A processing is effective in enhancing the texture formation while the texture is lost by a subsequent pressing when adopting route C. Therefore, compaction of Nd13.5Fe73.8Co6.7B5.6Ga0.4 alloy powder using route A ECAP passes with 0.5 GPa backpressure at 823 K results in pronounced texture, which is beneficial for anisotropic hard magnetic properties.

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Developments in the processing and properties of NdFeb-type permanent magnets

Cited by 385 publications

References 9 publications

Net Shape 3D Printed NdFeB Permanent Magnet

Net Shape 3D Printed NdFeB Permanent Magnet

3D print of polymer bonded rare-earth magnets, and 3D magnetic field scanning with an end-user 3D printer

Effect of Processing Parameters on the Magnetic Properties and Macrotexture of a Nd_13.5Fe_73.8Co_6.7B_5.6Ga_0.4Alloy Processed by Equal Channel Angular Pressing With Back Pressure

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Developments in the processing and properties of NdFeb-type permanent magnets

Cited by 385 publications

References 9 publications

Net Shape 3D Printed NdFeB Permanent Magnet

Net Shape 3D Printed NdFeB Permanent Magnet

3D print of polymer bonded rare-earth magnets, and 3D magnetic field scanning with an end-user 3D printer

Effect of Processing Parameters on the Magnetic Properties and Macrotexture of a Nd13.5Fe73.8Co6.7B5.6Ga0.4Alloy Processed by Equal Channel Angular Pressing With Back Pressure

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Product

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Effect of Processing Parameters on the Magnetic Properties and Macrotexture of a Nd_13.5Fe_73.8Co_6.7B_5.6Ga_0.4Alloy Processed by Equal Channel Angular Pressing With Back Pressure