Manufacturing Process
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Permanent Magnet Manufacturing Process
At PermanentMagnet.net, we have built a reputation for delivering high-performance permanent magnets through a refined, technologically advanced, and quality-controlled manufacturing process. Our manufacturing system combines decades of experience, high-grade materials, and precision engineering to create magnets that meet the exacting standards of modern industry.
Below is a step-by-step overview of our magnet manufacturing process:
1. Raw Material Preparation
The process begins with the careful selection of rare-earth and metallic materials such as Neodymium (Nd), Iron (Fe), Boron (B), Samarium (Sm), and Cobalt (Co). These materials are weighed and blended in strict proportions to create alloy compositions optimized for desired magnetic characteristics.
2. Alloy Melting & Strip Casting
The selected raw materials are melted in a vacuum induction furnace to form a homogenous molten alloy. The molten alloy is rapidly cooled using a strip casting process, forming thin metal flakes or ribbons. This rapid cooling is essential to ensure uniform grain structure and prevent unwanted crystallization.
3. Hydrogen Decrepitation & Jet Milling
The alloy strips undergo hydrogen decrepitation, which breaks them into coarse powder. This powder is then finely milled using jet milling, achieving particle sizes of a few microns. The resulting ultrafine magnetic powder is essential for producing high-density, high-coercivity magnets.
4. Pressing and Magnetic Alignment
The powder is then compacted into a mold using isostatic or die pressing, under a strong magnetic field. This aligns the magnetic domains along a single axis, producing anisotropic magnets with superior magnetic performance.
We offer pressing options such as:
- Axial pressing
- Radial pressing
- Transverse pressing
5. Sintering
The pressed blocks are sintered in a controlled atmosphere furnace at temperatures above 1000°C. Sintering densifies the material and initiates the metallurgical bonding process, converting the compact into a solid magnet. The sintering process also determines the magnet’s final grain structure and mechanical strength.
6. Aging and Heat Treatment
After sintering, the magnets are subjected to an aging or tempering process to stabilize their magnetic and mechanical properties. This ensures long-term stability in various environmental conditions.
7. Machining and Shaping
Sintered magnets are hard and brittle, requiring specialized diamond grinding tools to machine them into precise shapes and tolerances. We manufacture custom shapes, such as:
- Rings
- Discs
- Blocks
- Arcs
- Custom geometries (based on drawings or CAD files)
8. Surface Coating and Plating
To protect against corrosion and wear, we apply surface treatments tailored to the application:
- Nickel (Ni-Cu-Ni) coating for durability and aesthetics
- Epoxy for chemical resistance
- Zinc or Phosphate for basic protection
- Gold for biomedical or sensitive applications
9. Magnetization
The final products are magnetized using high-voltage impulse magnetizers. The magnetic orientation and field strength are set according to customer specifications:
- Axial
- Radial
- Multi-pole
- Custom directions
10. Final Inspection and Quality Control
Each magnet undergoes rigorous quality assurance testing:
- Magnetic properties (Br, Hc, BHmax)
- Dimensional accuracy
- Coating thickness and adhesion
- Salt spray and environmental resistance
- Batch traceability and compliance (RoHS, REACH, ISO 9001)
11. Packaging and Delivery
Magnets are carefully packed with magnetic shielding materials to comply with international shipping standards. Labels, barcodes, and batch information are provided for full traceability. Custom packaging is available upon request.
Why Our Manufacturing Process Stands Out
Advanced processing equipment
- In-house R&D and custom prototyping
- Strict quality assurance at every step
- Scalable production for small to bulk orders
- Tailored solutions for diverse industries
