NdFeB Magnet Demagnetization Detection by Surface Pole Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for evaluating the demagnetization state of grain boundary diffusion NdFeB magnets are inefficient, damaging the magnet, and require significant resources, as they involve cutting the magnet into layers and using large equipment, making it difficult to assess internal demagnetization without damaging the product.
Innovation Solution
A method involving the application of a reverse magnetic field to a saturation-magnetized grain boundary diffusion NdFeB magnet, observing the magnetic pole distribution on non-diffusion faces, which determines irreversible demagnetization without damaging the magnet, using devices like magnetic field distribution visualization tools.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the magnet is cut into layers for detection, then the internal demagnetization state can be evaluated, but the magnet is damaged and detection efficiency is low
Solution Approach 1:
The patent replaces the mechanical cutting method with a magnetic field-based detection method. By applying a reverse magnetic field and observing magnetic pole distribution changes on the magnet surface, internal demagnetization can be evaluated without physically cutting or damaging the magnet, thus maintaining both measurement precision and operational efficiency
Solution Approach 2:
The patent uses magnetic pole distribution as an intermediary indicator to reflect internal demagnetization state. Instead of directly measuring internal properties through cutting, the method observes the external manifestation (magnetic poles on surface) that indirectly reveals the internal condition, enabling non-destructive evaluation
2Measurement precision
If large equipment such as VSM, PPMS, MPMS is used for detection, then accurate demagnetization measurement can be obtained, but resource consumption is high
Solution Approach 1:
The patent employs simple, readily available magnetic field generation devices and observation methods instead of expensive specialized equipment like VSM or PPMS. The method uses basic magnets or electromagnets to generate reverse magnetic fields and observes magnetic pole distribution through simple means, significantly reducing resource consumption while maintaining detection capability
Solution Approach 2:
The magnet itself serves as both the object of detection and the indicator of its state. The magnetic pole distribution on the magnet surface directly reveals the internal demagnetization condition, eliminating the need for complex external measurement equipment and reducing resource requirements
3Measurement precision
If the magnet is cut into layers for detection, then each layer's coercivity can be analyzed, but the product integrity is compromised and further use is impossible
Solution Approach 1:
The patent replaces mechanical cutting with magnetic field interaction. By applying a reverse magnetic field and observing changes in magnetic pole distribution on the intact magnet surface, coercivity and demagnetization state can be analyzed without compromising product integrity, allowing the magnet to remain functional after detection
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 allows for accurate, non-destructive assessment of demagnetization with high efficiency, maintaining the integrity of the magnet and reducing resource consumption, and is applicable to magnets of various sizes and temperatures.
Implementation Method 1
a face of the magnet is coated with a heavy rare earth material, and the heavy rare earth material enters a grain boundary of the magnet
Implementation Method 2
applying a reverse magnetic field to a saturation-magnetization grain boundary diffusion NdFeB magnet, and, if a number of magnetic poles on a non-diffusion face of the grain boundary diffusion NdFeB magnet is increased
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The present application relates to a technical field of determining an irreversible demagnetization of a grain boundary diffusion NdFeB magnet, and more particularly, to a method for identifying an irreversible demagnetization of a grain boundary diffusion NdFeB magnet by magnetic field distribution. After applying a reverse magnetic field to a saturatedly magnetized grain boundary diffusion NdFeB magnet, if a number of magnetic poles on a non-diffusion face of the grain boundary diffusion NdFeB magnet is increased, it is determined that there is an irreversible demagnetization in the grain boundary diffusion NdFeB magnet. The method of the present application may not only detect whether there is the irreversible demagnetization in the grain boundary diffusion NdFeB magnet, but also restrain from damaging the integrity of the grain boundary diffusion NdFeB magnet.