Ring Shape Neodymium Sintered Magnet

/Ring Shape Neodymium Sintered Magnet
  • Neodymium Sintered Magnet

Ring Shape Neodymium Sintered Magnet N52 Neodymium Magnet, Magnetic Ring, Sintered Neo Magnet, High Energy Density Magnet, High BH Neodymium Magnet Supplier

Product Name:N52 Ring Shape Neodymium Sintered Magnet
Magnet ID:Ring-Ø20xØ4x7mm-N52-Ni
+ Highest Energy of All Permanent Magnets
+ Moderate Temperature Stability
+ High Coercive Strength
+ Moderate Mechanical Strength

1. Vacuum Melting
Compositions of neodymium, iron , iron-boron, dysprosium and minor additions including cobalt , copper , gallium, aluminum and others are mixed and induce-melted to form Nd2Fe14B phase and other necessary structures required for high performance permanent magnets. The melting temperature reaches over 1300o C. Usually repeated melting is needed to produce an even phase and structure distribution .

2. Crushing
The ingots from the vacuum melting process are crushed into coarse powder directly , or strip cast followed by HDDR processing into coarse powder .

3. Jet Milling
The coarse powder further milled into required particles sized about 3 microns in diameter by a jet miller . Those particles become single-domain and anisotropic whichare critical for producing a high coercivity magnet. Jet milling is the most effective way to mill the particles so far.

4. Pressing
Compact the fine powder to produce block magnets. Usually a magnetic field is applied during pressing to align those anisotropic particles in order to produce maximum magnetic output in a particular direction. There are two pressing methods, transverse and axial , depending on different applications. Isostatic pressing is normally used to further densify magnets to 75-80% .

5. Vacuum Sintering
The compacted magnets are sintered at temperatures above 1000 o C and for many hours to be solidified and compacted further more up to 99% by shrinking it’s body. A required microstructure between particles for high performance permanent magnets is also formed in this stage. Some following heat-treatments are needed to stabilize the magnets .

6. Machining
Shrinkage and distortion during sintering is too difficult to control adequately and magnets normally need at least a “ clean up” grind on the surface. Small parts are cut or sliced precisely to form a big block to meet the demanding tolerances and different shapes .

7. Surface Treatment
Various surface treatments can be applied on the final products . They include zinc, nickel ,Ni-Cu-Ni multi-layer, e-coating , epoxy and others. They provide different surface finishing, appearance and corrosion resistance, applicable to different application environments.

8. Inspection
This is the final step. Magnets are inspected based on customer specifications and needs, including dimensional and magnetic tests.

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Magnetisation Grade:         N52
Material: Rare Earth Neo, Neodymium-Iron-Boron (NdFeB), NIB
Magnet ID:              Ring-Ø20xØ4x7mm-N52-Ni
Plating / Coating:  Nickel (Ni-Cu-Ni) / Double Ni / Zinc (Zn) / Epoxy (Black/Gray) / Gold (Au)
Shape:         Ring
Ring Magnet Size:
Ring Total Diameter (D):      Ø 20 mm
Ring Inner Diameter (d):      Ø 4 mm
Ring Total Height (H):         7 mm
Tolerance:         ±0.05 mm
Magnetisation Direction:    Axial  /  Radial
Residual Magnetic Flux Density (Br): 1430-1480 mT (14.3-14.8 kGs)
Energy Density (BH)max:             398-422 KJ/m³  (50-53 MGOe)
Coercivity Force (Hcb):              ≥ 796 kA/m ( ≥ 10.0 kOe)
Intrinsic Coercivity Force (Hcj):    ≥ 876  kA/m ( ≥ 11 kOe)
Maximum Operation Temperature: 60 °C
Delivery Time:           14-35 days

Technical Drawing