Magnetic Stabilization of Neodymium-Iron-Boron Magnets
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Solution Overview
Problem
The high cost and excessive usage of heavy rare earth elements in permanent magnetic materials, particularly in neodymium-iron-boron magnets used in new energy vehicles and other applications, due to the conventional diffusion methods which require large quantities for enhancing coercivity, pose a significant challenge.
Innovation Solution
A magnetic stabilization method involving a physical sputtering or chemical coating process to form thin films with varying concentrations of heavy rare earth elements on specific faces of neodymium-iron-boron substrates, followed by heat treatment, allowing for a reduced usage of heavy rare earth elements while maintaining or improving coercivity by controlling the distribution of these elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional heavy rare earth element diffusion process is used to improve coercivity, then coercivity is improved, but heavy rare earth element consumption increases and cost increases
Solution Approach 1:
The patent applies local quality by forming thin films with varying concentrations of heavy rare earth elements on specific faces of the neodymium-iron-boron substrate. Different regions of the substrate receive different amounts of heavy rare earth elements based on their specific coercivity requirements, rather than uniformly treating the entire surface. This localized approach improves coercivity where needed while minimizing overall heavy rare earth element consumption.
Solution Approach 2:
The patent utilizes parameter changes by controlling the concentration distribution of heavy rare earth elements in the thin films through physical sputtering or chemical coating processes. By adjusting deposition parameters such as sputtering power, coating time, and film thickness, the patent achieves optimized coercivity enhancement with reduced heavy rare earth element usage compared to conventional diffusion methods.
2Strength
If heavy rare earth content is increased to improve magnetic performance, then coercivity and resistance to demagnetization are improved, but manufacturing cost increases significantly
Solution Approach 1:
The patent reduces manufacturing cost by applying heavy rare earth elements locally on specific faces of the substrate rather than throughout the entire magnet. This localized enhancement achieves the required resistance to demagnetization in critical areas while minimizing the total quantity of expensive heavy rare earth materials needed, thereby reducing overall manufacturing cost.
Solution Approach 2:
The patent applies partial action by forming thin films only on specific faces of the neodymium-iron-boron substrate rather than treating the entire surface. This selective approach provides sufficient coercivity enhancement and demagnetization resistance for the application while using a relatively small amount of heavy rare earth elements, optimizing the balance between performance and cost.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method effectively reduces the overall cost of permanent magnets by minimizing the amount of heavy rare earth elements used while ensuring stable magnetization and customized coercivity distribution, meeting specific resistance to demagnetization requirements at different positions.
Implementation Method 1
high-temperature heat treatment is performed on the thin film to make the heavy rare earth element such as Dy or Tb diffuse from the surface of the neodymium-iron-boron substrate into the neodymium-iron-boron substrate along a grain boundary
Implementation Method 2
A physical sputtering method may be used to perform processing on the first face to form the thin film
Implementation Method 3
Alternatively, a chemical coating method may be used to coat slurry on the first face
Data Source
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AI summary
This application discloses a permanent magnet with stable magnetization, and the permanent magnet with stable magnetization may be used on new energy vehicles, wind power generation, energy-saving appliances, smart manufacturing, and other fields. The permanent magnet with stable magnetization has one magnetization direction, the permanent magnet with stable magnetization includes a heavy rare earth element, and the heavy rare earth element is dispersed in the permanent magnet with stable magnetization and has a varying concentration along a direction perpendicular to the magnetization direction. When magnetic stabilization processing is performed on the permanent magnet with stable magnetization, a permanent magnet with stable magnetization that meets different requirements on resistance to demagnetization at different positions can be obtained simply by forming, on a first face of a permanent magnet substrate, a thin film with a varying thickness or a thin film with a varying concentration of the heavy rare earth element. In addition, this further reduces a usage quantity of the heavy rare earth elements.