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Technology

Extrusion-Compression Method for Producing Bonded Permanent Magnets

Topic:

Invention Reference Number

201804254
3D printed permanent magnets

Permanent bonded magnets are integral in various applications due to their strong magnetic properties and durability. Traditional methods of producing these magnets face challenges such as high viscosity, high melting points, and degradation of materials at elevated temperatures. These issues hinder the production of magnets with complex shapes and consistent magnetic properties. Additionally, recycling used bonded magnets is a complicated process, often leading to decreased performance in recycled products.

Description

This invention introduces a novel extrusion-compression method to produce bonded permanent magnets with high magnetic particle loading (≥80 vol %) and uniform magnetic properties. The process involves three key steps:

  1. Low-shear compounding: A thermoplastic polymer and magnetic particles are mixed to form an initial homogeneous mixture.
  2. Low-shear plasticating: The mixture is fed into a plasticator with a low-shear single screw within a heated barrel, transforming it into solid pellets.
  3. Compression molding: The pellets are molded under compression to form the final bonded magnet. This method allows the creation of complex shapes and consistent magnetic properties, making it a significant advancement over conventional techniques.

Benefits

  • High magnetic particle loading: Achieves ≥80 vol % magnetic particle content.
  • Uniform magnetic properties: Variance in magnetic properties is less than 5%.
  • Complex shapes: Capable of producing magnets in intricate shapes, including gears and tools.
  • Recycling capability: Efficiently recycles used bonded magnets, maintaining high performance.

Applications and Industries

  • Electric motors: Enhances performance and efficiency in electric motors due to high magnetic strength and uniformity.
  • Automotive industry: Used in sensors, actuators, and electric vehicle motors.
  • Aerospace: Provides reliable magnetic components for various aerospace applications.
  • Renewable energy: Used in wind turbines and other renewable energy systems requiring high-performance magnets.
  • Electronics: Essential for components in electronic devices that require precise and strong magnetic fields.

Contact

To learn more about this technology, email partnerships@ornl.gov or call 865-574-1051.