Neodymium-iron-boron rare earth permanent magnet material magnetizing method and device

Abstract

The application relates to the technical field of permanent magnet material magnetization, in particular to a neodymium iron boron rare earth permanent magnet material magnetization method and device, which comprises the following steps: acquiring the magnetic characteristic parameters of neodymium iron boron material to be magnetized; based on the magnetic characteristic parameters, a starting magnetization sequence and a target magnetization sequence are matched from a pre-constructed multi-parameter adaptive magnetization sequence library; a connection transition sequence is inserted between the starting magnetization sequence and the target magnetization sequence, which is used for smoothly transitioning the magnetic field intensity of the magnetization process from a starting level to a target level via the connection transition sequence; and a magnetization process composed of the starting magnetization sequence, the target magnetization sequence and the connection transition sequence is executed. Through the application, the problem of uneven magnetization in the thickness direction of the material can be solved, and the magnetization process is smoothly realized from the surface layer to the deep layer.

Description

Technical Field

[0001] This invention relates to the technical field of magnetizing permanent magnet materials, and in particular to a method and apparatus for magnetizing neodymium iron boron rare earth permanent magnet materials. Background Technology

[0002] To impart the desired magnetic properties to neodymium iron boron rare earth permanent magnet materials, they need to be magnetized. Existing magnetization methods often employ multi-stage magnetic fields to overcome the potential for insufficient magnetization caused by a single pulsed magnetic field. For example, multiple sequences of pulsed magnetic fields with increasing intensity are applied to achieve a deeper magnetization effect on the material.

[0003] However, existing methods typically treat the material as a uniformly magnetic whole, and the applied multi-level magnetic field sequence is pre-set uniformly. This fails to finely adapt to the actual magnetic property gradient distribution that exists in the material along its thickness, such as differences in coercivity or stress state from the surface to the interior due to fabrication processes. Because the magnetization threshold and response characteristics differ at different depths, existing methods struggle to achieve synchronous and sufficient optimal magnetization across the entire material thickness, resulting in the overall magnetization uniformity and potential properties of the material not being fully activated. Summary of the Invention

[0004] This invention provides a method and apparatus for magnetizing neodymium iron boron rare earth permanent magnet materials, which can effectively solve the problems in the background art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for magnetizing neodymium iron boron rare earth permanent magnet materials includes: Obtain the magnetic property parameters of the neodymium iron boron material to be magnetized; Based on the magnetic property parameters, the starting magnetization sequence and the target magnetization sequence are matched from a pre-built multi-parameter adaptive magnetization sequence library; A transition sequence is inserted between the initial magnetization sequence and the target magnetization sequence to smoothly transition the magnetic field strength of the magnetization process from the initial level to the target level via the transition sequence. The magnetization process consisting of the initial magnetization sequence, the target magnetization sequence, and the transition sequence is executed. The initial magnetization sequence, the target magnetization sequence, and the transition sequence all include a gradient magnetic field magnetization path based on the material thickness and coercivity of the NdFeB material to be magnetized. The gradient magnetic field magnetization path has a transition magnetization section with nonlinear increase in magnetic field strength and a stable magnetization section with constant magnetic field strength.

[0006] Furthermore, the magnetic property parameters include at least the material thickness, coercivity, easy magnetization direction, and magnetic property distribution in the thickness direction.

[0007] Furthermore, the multi-parameter adaptive magnetization sequence library is generated based on a combination of multiple classification dimensions, including the material's easy magnetization direction angle, thickness range, and residual stress level.

[0008] Furthermore, in the process of matching the initial magnetization sequence and the target magnetization sequence, the initial magnetization sequence is preferentially adapted to the surface magnetic properties of the material, and the target magnetization sequence is preferentially adapted to the deep magnetic properties of the material.

[0009] Furthermore, the rate of change of magnetic field strength of the transition sequence is derived from the rate of change of magnetic field of the initial magnetization sequence and the target magnetization sequence.

[0010] Furthermore, the construction of the multi-parameter adaptive magnetization sequence library includes: Each dimension, including easy magnetization direction angle, thickness range, and residual stress level, is divided into subclasses according to the influence of magnetic properties on magnetization parameters. The boundaries of the subclasses are verified through experiments. Each magnetization sequence corresponds to a subclass combination in the three-dimensional classification system. The sequence parameters are calibrated through orthogonal experiments, and fixed parameters are selected with magnetization uniformity as the optimization objective. The magnetization sequence is stored in the database in an association form between three-dimensional subclass combinations and parameter sets.

[0011] Furthermore, insert agglutination transition sequences, including: Magnetic property parameters of the middle layer region are extracted from the magnetic property distribution data in the thickness direction. The parameters of the transition sequence are calculated based on the parameters of the initial magnetization sequence, the target magnetization sequence, and the magnetic property parameters of the middle layer. The parameters of the transition sequence include the initial magnetic field strength, nonlinear variation coefficient, and final magnetic field strength of the transition magnetization segment, as well as the magnetic field strength and duration of the stable magnetization segment.

[0012] Furthermore, the initial magnetic field strength adopts the stable segment magnetic field strength of the initial magnetization sequence, the final magnetic field strength adopts the initial magnetic field strength of the transition segment of the target magnetization sequence, the nonlinear variation coefficient is obtained by combining the variation coefficients of the initial and target sequences using the weighted average method of the middle layer permeability, the stable segment magnetic field strength is determined based on the average coercivity of the middle layer, and the stable magnetization time is determined based on the average residual stress of the middle layer.

[0013] Furthermore, the method for determining the magnetic property parameters of the middle layer region includes: At least three detection nodes are selected in the middle layer region along the material thickness direction, corresponding to the near-surface, center and near-deep layers of the middle layer, respectively; Extract the coercivity, permeability and residual stress parameters of each node, and calculate the average coercivity, average permeability and average residual stress of the middle layer.

[0014] On the other hand, the present invention also provides a magnetizing device for neodymium iron boron rare earth permanent magnet materials, comprising: The parameter acquisition module is used to acquire the magnetic property parameters of the neodymium iron boron material to be magnetized; The sequence matching module is used to match the starting magnetization sequence and the target magnetization sequence from a pre-built multi-parameter adaptive magnetization sequence library based on the magnetic property parameters. A sequence construction module is used to insert a transition sequence between the initial magnetization sequence and the target magnetization sequence, wherein the transition sequence smoothly transitions the magnetic field strength of the magnetization process from the initial level to the target level. The process execution module is used to execute the complete magnetization process consisting of the starting magnetization sequence, the transition sequence, and the target magnetization sequence. The initial magnetization sequence, the target magnetization sequence, and the transition sequence all include a gradient magnetic field magnetization path based on the material thickness and coercivity of the NdFeB material to be magnetized. The gradient magnetic field magnetization path includes a transition magnetization section with nonlinearly increasing magnetic field strength and a stable magnetization section with constant magnetic field strength.

[0015] The technical solution of this invention can achieve the following technical effects: by combining a layered adaptation strategy with a dynamic connection mechanism, the transformation from homogeneous magnetization to gradient magnetization is realized; the matching process between the initial magnetization sequence and the target magnetization sequence enables targeted magnetization of different depth regions, while the insertion of the transition sequence ensures the continuity of the magnetization process, so that the magnetic field can smoothly increase from the strength of the adaptation surface layer to the strength of the adaptation depth layer at the optimal rate, forming a continuous and abrupt dynamic magnetic field pattern; the change of this dynamic magnetic field pattern on the time axis can map the magnetic property gradient distribution of the material in the thickness direction, thereby guiding the magnetization process to achieve smooth magnetization from the surface layer to the depth layer.

[0016] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic flowchart of the magnetization method for neodymium iron boron rare earth permanent magnet materials of the present invention. Figure 2 This is a logic block diagram of the magnetization device for neodymium iron boron rare earth permanent magnet material in this invention. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0021] like Figure 1 As shown, the magnetization method for neodymium iron boron rare earth permanent magnet materials of the present invention specifically includes the following steps: Step S1: Obtain the magnetic property parameters of the neodymium iron boron material to be magnetized; Step S2: Based on the magnetic property parameters, the starting magnetization sequence and the target magnetization sequence are matched from the pre-built multi-parameter adaptive magnetization sequence library; Step S3: Insert a transition sequence between the initial magnetization sequence and the target magnetization sequence to smoothly transition the magnetic field strength of the magnetization process from the initial level to the target level via the transition sequence. Step S4: Execute the magnetization process consisting of the initial magnetization sequence, the target magnetization sequence, and the transition sequence; The initial magnetization sequence, the target magnetization sequence, and the transition sequence all include a gradient magnetic field magnetization path based on the material thickness and coercivity of the NdFeB material to be magnetized. The gradient magnetic field magnetization path has a transition magnetization section with nonlinear increase in magnetic field strength and a stable magnetization section with constant magnetic field strength.

[0022] In this embodiment, by combining a layered adaptation strategy with a dynamic connection mechanism, the transition from homogeneous magnetization to gradient magnetization is achieved. The matching process between the initial magnetization sequence and the target magnetization sequence enables targeted magnetization of different depth regions, while the insertion of the transition sequence ensures the continuity of the magnetization process, allowing the magnetic field to grow smoothly from the strength of the adaptable surface layer to the strength of the adaptable deep layer at the optimal rate, forming a continuous and abrupt dynamic magnetic field pattern. The change of this dynamic magnetic field pattern on the time axis can map the magnetic property gradient distribution of the material in the thickness direction, thereby guiding the magnetization process to achieve smooth magnetization from the surface layer to the deep layer. Specifically, a controllable magnetic field time waveform is formed by the nonlinearly rising transition magnetization segment and the smooth sequence connection, enabling the magnetic domain flipping region inside the material to advance from the surface to the depth at a uniform speed. This minimizes internal stress caused by asynchronous magnetization and improves the overall magnetization uniformity. Secondly, it forms an adaptive magnetization capability. By acquiring parameters, matching sequences, inserting transitions, and executing processes, an adaptively adjustable magnetization framework is constructed. This framework can automatically generate customized magnetization paths for materials of different thicknesses, batches, and internal characteristics, ensuring product consistency. In addition, energy efficiency is optimized while ensuring sufficient magnetization. Because the magnetic field is applied smoothly, it avoids the energy waste and potential thermal damage caused by applying ultra-high magnetic fields instantaneously to impact the deep layers, making the energy application more closely match the actual needs of material magnetization.

[0023] In a specific implementation, as one example, to achieve the technical objective of acquiring magnetic characteristic parameters in step S1, an integrated detection device is used. This integrated detection device includes a laser thickness measurement module, an array-type vibrating sample magnetometer probe group, a three-dimensional displacement platform, and a data fusion processing unit. The laser thickness measurement module is used to acquire material thickness and thickness information at the detection location. The array-type vibrating sample magnetometer probe group contains multiple independent detection probes, with the probe spacing adapted to the thickness of the material to be tested to cover the entire thickness range. The three-dimensional displacement platform can move the array-type vibrating sample magnetometer probe group along the material thickness direction and accurately position it. The data fusion processing unit is used to bind thickness data and magnetic characteristic data and establish a correlation. The specific detection method is as follows: Step S11: Fix the neodymium iron boron material to be magnetized on the stage of the three-dimensional displacement platform, so that the material thickness direction is parallel to the moving direction of the array-type vibrating sample magnetometer probe group; start the laser thickness measurement module, collect thickness data at different positions along the material thickness direction, and determine the average value of the collected data as the initial thickness of the material. During the acquisition process, ensure that the detection beam of the laser thickness measurement module is perpendicular to the material surface. Step S12: Based on the initial thickness, the data fusion processing unit divides the material thickness direction into multiple continuous detection nodes. The nodes cover the material surface, transition layer and deep region. The spacing between adjacent nodes is uniform to ensure the continuity of detection and ensure that there are no detection blind spots in the entire thickness range. Step S13: Start the three-dimensional displacement platform and move the array-type vibrating sample magnetometer probe group along the material thickness direction so that the detection center of each probe is aligned with each detection node. Adjust the distance between the probe and the material surface to the required detection range. Simultaneously start the laser thickness measurement module and the array-type vibrating sample magnetometer probe group. The laser thickness measurement module collects the thickness data at the current detection position, and the array-type vibrating sample magnetometer probe group collects the coercivity and easy magnetization direction data of the corresponding node. Collect and record the data of each group simultaneously. Step S14: The data fusion processing unit uses a preset algorithm to bind the position coordinates of each detection node with the coercivity and easy magnetization direction data of the corresponding node, forming an associated dataset containing thickness position, coercivity, and easy magnetization direction; with thickness position as the reference, the magnetic property data of each node is processed continuously, the transition data between adjacent nodes is completed, and finally, complete thickness direction magnetic property distribution data is generated.

[0024] In existing technologies, material thickness and magnetic property parameters are usually detected stepwise using independent devices. Thickness measurement and magnetic property detection lack a clear spatial relationship, and only isolated thickness values ​​and discrete magnetic property data can be obtained, which cannot directly reflect the variation law of magnetic properties in the thickness direction. The essential difference of this embodiment is that it realizes the integrated synchronous detection of thickness parameters and magnetic property parameters. Through the collaboration of array probes and displacement platform, each set of magnetic property parameters is directly anchored to the specific position in the material thickness direction, forming a one-to-one correspondence between thickness position and magnetic property parameters, rather than a simple superposition of isolated parameters.

[0025] In this embodiment, the synchronous detection mode eliminates the reference deviation of step-by-step measurement. Laser thickness measurement and magnetic property detection are based on the same spatial positioning reference, avoiding the error caused by the non-coincidence of the thickness measurement reference and the magnetic property detection reference in traditional methods. The node coverage and continuous data processing of the full thickness range can characterize the gradual change law of magnetic properties from the surface to the deep layer, providing magnetic property data support for the parameter design of the transition sequence in the intermediate region. A single detection process completes the acquisition of all parameters, avoiding positional shifts caused by multiple material clamping and improving the consistency of parameter detection.

[0026] In some embodiments of the present invention, in order to achieve sequence matching in step S2, a targeted matching mechanism between magnetic property parameters and magnetization sequence is established based on the associated dataset obtained in step S1, so as to ensure that the initial magnetization sequence is adapted to the surface magnetic properties of the material and the target magnetization sequence is adapted to the deep magnetic properties of the material.

[0027] Specifically, the multi-parameter adaptive magnetization sequence library is generated based on a combination of multiple classification dimensions, including the material's easy magnetization direction angle, thickness range, and residual stress level. The subclass division and corresponding magnetization sequence parameters for each classification dimension are determined experimentally. The specific construction method is as follows: Step S211: In the multi-parameter adaptation magnetization sequence library, each dimension is divided into subclasses according to the influence law of magnetic properties on magnetization parameters. The subclass boundaries are verified through a large number of experiments to ensure that the magnetization requirements of similar materials are consistent. Regarding the easy magnetization direction angle dimension: Based on the mainstream easy magnetization direction of the material, subcategories are divided according to the sensitivity threshold of magnetic domain orientation to magnetic field direction, ensuring that the magnetic field direction parameters within the subcategories do not need to be adjusted to meet the magnetic domain orientation requirements; the subcategories cover the deviation range of common easy magnetization directions, and each subcategory corresponds to a clear angle interval, with the interval division based on the principle that there is no significant difference in magnetic domain orientation efficiency; Regarding the thickness range: subcategories are formed based on the penetration characteristics of the magnetic field in NdFeB materials. The subcategories are linearly related to the magnetic field penetration time. The ranges cover the commonly used thicknesses of NdFeB materials in industrial production. The magnetic field parameters matched to each subcategory can ensure that the magnetic field penetrates the corresponding thickness of the material uniformly. Regarding the residual stress level dimension: subcategories are formed according to the influence of residual stress on the stable orientation of magnetic domains. The subcategories are based on the experimental relationship between stress and magnetic domain stabilization time. Each subcategory corresponds to an appropriate magnetic field stabilization time parameter to ensure that magnetic domains can be fully oriented under stress conditions. Step S212: Each magnetization sequence corresponds to a subclass combination of the three-dimensional classification system. The sequence contains the core parameters of the gradient magnetic field magnetization path, specifically the initial magnetic field strength and nonlinear change coefficient of the transition magnetization segment, and the magnetic field strength and duration of the stable magnetization segment. Step S213: The parameter calibration of the magnetization sequence is completed through orthogonal experiments. Using the typical magnetic property parameters of the corresponding sub-type materials as variables, multiple sets of magnetic field parameter combination schemes are designed. After magnetization experiments are conducted on each scheme, the magnetization uniformity of the material is detected, and the parameter combination with the best magnetization uniformity is selected as the fixed parameters of the sequence. Step S214: Store all magnetization sequences in the database in an association form that combines three-dimensional subclass combinations with parameter sets. The database supports fast retrieval by three-dimensional subclass information to ensure efficient matching process.

[0028] More specifically, when matching the corresponding magnetization sequence in the multi-parameter adaptation magnetization sequence library, the detection data from step S1 is used as input, and the matching operation is completed through parameter extraction, classification mapping, sequence retrieval, and verification. The specific matching process is as follows: Step S221: Extract key magnetic property parameters of the surface and deep layers from the thickness-direction magnetic property distribution data generated in step S1. The selection of extraction nodes is based on the principle of excluding surface oxide layers and processing defect areas to ensure that the extracted parameters can reflect the true characteristics of the effective magnetization area of ​​the material. The surface parameter extraction node is located in the effective surface area of ​​the material thickness direction, and the deep parameter extraction node is located in the effective deep area of ​​the material thickness direction. Both nodes are located in the defect-free area inside the material. The extracted parameters include the easy magnetization direction angle, thickness assignment information, and residual stress value. After extraction, abnormal data is removed through a data verification mechanism to ensure the integrity and accuracy of the parameters.

[0029] Step S222: Match the extracted surface and deep parameters with the corresponding dimensions of the 3D classification system to determine the subclass to which each parameter belongs. The mapping process includes explicit boundary handling rules to ensure accurate matching even when the parameter is at the subclass boundary. The specific mapping matching is as follows: For easy magnetization direction angle mapping: compare the detected angle value with the subclass interval of the easy magnetization direction angle dimension to determine the subclass; if the angle value is at the boundary of two subclasses, select the subclass according to the principle of minimum angle difference; For thickness attribution mapping: determine the subclass of the material in the thickness range dimension based on the overall thickness of the material, and ensure that the matching sequence parameters are adapted to the magnetic field penetration requirements corresponding to the material thickness; For residual stress mapping: the detected stress value is compared with the subclass interval of the residual stress level dimension to determine the subclass and ensure that the matching sequence parameters are adapted to the magnetic domain stability requirements corresponding to the stress.

[0030] Step S223: Based on the subclass combination of surface parameters, retrieve candidate starting magnetization sequences from the sequence library; based on the subclass combination of deep parameters, retrieve candidate target magnetization sequences; after retrieval, start adaptation verification, and the verification is sorted according to priority rules to ensure accurate matching of core parameters; the priority rules are as follows: First priority verification: accuracy of the easy magnetization direction angle matching, ensuring that the deviation between the magnetic field direction parameters of the sequence and the easy magnetization direction of the material is within the allowable range, which is determined based on the magnetic domain orientation efficiency test; Second priority verification: thickness and stress parameter compatibility, ensuring that the magnetic field penetration parameters and stabilization time parameters of the sequence are adapted to the thickness and stress characteristics of the material, respectively; If the verification fails, a parameter fine-tuning mechanism is triggered, which generates an adaptation sequence based on the sequence parameters of neighboring subclasses to ensure that the sequence parameters match the material properties.

[0031] Step S224: Cross-validate the candidate initial magnetization sequence with the surface coercivity parameters to ensure that the magnetic field strength of the stable magnetization segment of the sequence meets the requirement for complete orientation of the surface magnetic domains; cross-validate the candidate target magnetization sequence with the deep coercivity parameters to ensure that the magnetic field strength is suitable for the deep magnetization requirements. Simultaneously verify the deviation of the easy magnetization direction parameters between the initial and target sequences to ensure that the deviation meets the requirements for subsequent connection. After all validations are passed, output the final initial and target magnetization sequences and store them associated with the material's unique identifier.

[0032] In this embodiment, the surface and deep layers of the material are treated as independent adaptation objects. A precise correspondence between magnetic property parameters and sequences is achieved based on a three-dimensional classification system. The sequence parameters are designed for the magnetic properties of specific regions, rather than being a coarse adaptation based on average parameters, fundamentally solving the problem of sequence decoupling from material properties. The initial magnetization sequence parameters are highly adapted to the surface magnetic properties, avoiding abnormal surface magnetic domain orientation caused by inappropriate magnetic field strength. The target magnetization sequence parameters are adapted to the deep magnetic properties, ensuring sufficient magnetic field penetration and meeting the deep magnetic domain orientation requirements, achieving differentiated optimized magnetization across the entire thickness range of the material. The structured design of the three-dimensional classification system makes the sequence matching process traceable, with each matching result corresponding to specific magnetic property parameters. The pre-built sequence library supports rapid retrieval, and the sequence matching process for a single material is highly efficient, meeting the efficiency requirements of mass production and avoiding production interruptions caused by multiple sequence adjustments.

[0033] In a specific implementation, as an example, in order to construct and insert the transition sequence in step S3, a transition sequence for adapting the magnetic properties of the middle layer of the material is constructed based on the full-thickness magnetic property data obtained in step S1 and the starting and target magnetization sequences output in step S2, so that the magnetic field strength of the magnetization process smoothly transitions from the starting level to the target level, avoiding abrupt changes in magnetic field parameters caused by direct connection of sequences.

[0034] The initial magnetization sequence is adapted to the material surface, and the target magnetization sequence is adapted to the material depth. In the middle layer region between the surface and deep layers along the material thickness direction, the coercivity, permeability, and residual stress exhibit a continuous, gradual change. If the two sequences are directly connected, the abrupt change in magnetic field strength and rate of change will lead to disordered magnetic domain orientation in the middle layer: the magnetic field adapted to the surface layer cannot meet the gradual magnetization threshold of the middle layer, while the magnetic field adapted to the deep layer may cause overmagnetization in the transition region of the middle layer. Therefore, the connecting transition sequence must simultaneously meet the following requirements: firstly, seamless connection with the parameters of the initial and target sequences; and secondly, adaptation to the gradually changing magnetic properties of the middle layer region. The specific construction and insertion implementation are as follows: Step S31: From the thickness-direction magnetic property distribution data generated in Step S1, select three core detection nodes in the middle layer region, corresponding to the near-surface, center, and near-deep layers of the middle layer, respectively. The nodes are evenly spaced to cover the gradual transition range of the middle layer and eliminate interference from surface and deep layer parameters. Extract the coercivity, permeability, and residual stress parameters of each node. The data are all from the associated dataset in Step S1 and no additional detection is required. The extracted data is calibrated. If the difference between a node parameter and its adjacent nodes exceeds the normal fluctuation range of the material's magnetic properties, it is judged as abnormal data and is completed using linear interpolation. The average coercivity of the middle layer is the arithmetic mean of the coercivity of the three nodes, the average permeability of the middle layer is the arithmetic mean of the permeability of the three nodes, and the average residual stress of the middle layer is the arithmetic mean of the residual stress of the three nodes. Form a middle layer characteristic parameter table and associate it with the material's unique number.

[0035] Step S32: The parameters of the transition sequence include the initial magnetic field strength, nonlinear variation coefficient, and final magnetic field strength of the transition magnetization segment, as well as the magnetic field strength and duration of the stable magnetization segment. All parameters are calculated based on the initial and target sequence parameters and the intermediate layer characteristic parameters; specifically as follows: The initial magnetic field strength is directly adopted from the stable section magnetic field strength of the initial magnetization sequence to ensure seamless connection with the output end of the initial sequence; the final magnetic field strength is directly adopted from the initial magnetic field strength of the transition section of the target magnetization sequence to ensure seamless connection with the input end of the target sequence. This design is based on the fact that instantaneous changes in magnetic field strength can cause magnetic domains to reverse and cause orientation disorder, so the magnetic field strength at both ends must be completely consistent with the adjacent sequence. The nonlinear variation coefficient is obtained by using the permeability weighted average method, with the distribution characteristics of the middle layer permeability as the basis for weight allocation, combined with the variation coefficients of the initial sequence and the target sequence. The weight allocation logic is that the higher the permeability, the smaller the resistance to the propagation of the magnetic field in the material, and the higher the rate of change that can be tolerated. The final calculated variation coefficient is between the variation coefficients of the initial and target sequences, thus realizing the gradual change of parameters. The magnetic field strength in the stable section is taken as 1.8 to 2.5 times the average coercivity of the middle layer. This range is determined by NdFeB magnetic domain orientation test, which can ensure the complete orientation of magnetic domains and avoid energy redundancy. The stable magnetization time is determined based on the average residual stress of the middle layer, and the corresponding relationship is consistent with the stress-time matching rule in step S2, ensuring that the middle layer magnetic domains obtain sufficient stable orientation time.

[0036] Step S33: Based on the above parameters, construct a gradient magnetic field magnetization path consistent with the structure of the initial and target sequences. The path is divided into a transition magnetization segment and a stable magnetization segment to ensure the continuity of the magnetic field change pattern. The magnetic field strength of the transition magnetization segment changes according to a quadratic function, and the function form is completely consistent with the transition segment of the initial and target sequences. The duration of the transition segment is determined by back-calculating the magnetic field strength at the end of the transition segment to ensure that the magnetic field strength at the end of the transition segment is precisely aligned with the initial magnetic field strength of the target sequence. The stable magnetization segment starts after the transition segment ends, and the magnetic field strength remains constant with the magnetic field strength of the stable segment. The duration is the determined stable magnetization time, providing a stable orientation environment for the middle magnetic domains. After the path is constructed, its rationality is ensured through parameter logic verification: the magnetic field strength at any position in the middle layer must be between the strength of the stable segment of the initial sequence and the initial strength of the transition segment of the target sequence to avoid local over-strength or under-strength.

[0037] Step S34: Integrate the starting magnetization sequence, the transition sequence, and the target magnetization sequence in the order of starting, transition, and target to form a complete magnetization process. The integration process needs to be verified by both timing and parameters. The temporal continuity verification method includes: ensuring that the start and stop times of the three sequences are completely connected, that the end time of the stable segment of the starting sequence coincides with the start time of the transition segment of the connecting sequence, and that the end time of the stable segment of the connecting sequence coincides with the start time of the transition segment of the target sequence, so as to avoid magnetic field interruption or superposition. The parameter continuity verification methods include: first, magnetic field strength verification, which involves plotting the magnetic field strength and time curves of the three sequences to ensure that there is no difference between the strength of the stable segment of the starting sequence and the initial strength of the connecting sequence, and no difference between the strength of the end point of the connecting sequence and the initial strength of the target sequence, and that the fluctuation of the magnetic field strength in the stable segment is controlled within the allowable range of the magnetization process; second, easy magnetization direction verification, which ensures that the deviation of the magnetic field direction of the three sequences meets the technical requirements of continuous magnetic domain orientation; and third, rate of change verification, which controls the difference in the rate of change of the magnetic field at the junction of adjacent sequences within a range that avoids sudden shocks. After successful verification, the integrated complete magnetization process is output, and the connection sequence parameters, mid-layer characteristic parameter table, and unique material numbers associated with the verification record are stored to meet the quality traceability requirements.

[0038] In this embodiment, the middle layer region is treated as an independent magnetization object, and parameters are designed based on the precise data from step S1, rather than ignoring or using general parameters. The core parameters of the connection sequence are derived from the initial and target sequence parameters and the magnetic properties of the middle layer. The parameters are gradually changed from the surface to the deep layer through weight calculation, rather than a simple numerical transition. The functional form of the gradient path is completely consistent with the initial and target sequences, ensuring the continuity of the magnetic field change. The connection sequence parameters are precisely matched with the magnetic properties of the middle layer, so that the magnetic domains in each region of the middle layer are fully oriented, avoiding local under-magnetization or over-magnetization. In the integrated magnetization process, the magnetic field strength gradually changes from the surface adaptation value through the middle layer to the deep layer adaptation value without any breaks or abrupt changes, ensuring the synchronous magnetic domain orientation across the entire thickness range of the material. The gradient path form of the connection sequence is consistent with the initial and target sequences, so there is no need to adjust the core logic of the magnetization process. Integration can be achieved simply through parameter adaptation, reducing the process debugging cost.

[0039] In a specific implementation, as one example, in step S4, the execution quality of the magnetization process directly determines the final magnetic properties of the material. The magnetization process needs to meet the following conditions: First, the continuity of the sequence execution. The timing and parameter connection of the starting, connecting, and target sequences must completely match the integration standard of step S3. If there are timing gaps or parameter abrupt changes, it will lead to disordered orientation of the middle-layer magnetic domains, destroying the continuous magnetization effect. Second, the controllability of the execution process. Factors such as load fluctuations of the magnetization equipment and material positioning deviations can easily cause magnetic field parameter deviations. Real-time adjustment is needed to ensure that the parameters are consistent with the sequence design. The specific implementation is as follows: Step S41: Fix the NdFeB material to be magnetized at the magnetization station. By adjusting the material's orientation, ensure that the parallelism error between the material's thickness direction and the direction of the magnetic field is controlled within the matching requirements of the magnetic field direction and the easy magnetization direction, and avoid positional shift that could cause the magnetic field direction deviation to exceed the standard. The integrated magnetization sequence parameters and mid-layer characteristic parameter table associated with the material are retrieved from the database and subjected to dual verification: The first verification is the completeness of the parameters, confirming that the core parameters such as the transition segment function form, the stable segment magnetic field strength, and the duration of the three sequences are not missing; the second verification is the correlation of the parameters, verifying the consistency between the initial strength of the connecting sequence and the stable segment strength of the starting sequence, and the consistency between the final strength of the connecting sequence and the initial strength of the transition segment of the target sequence, ensuring complete matching with the construction logic of step S3; if the verification fails, the parameter reloading process is triggered, and the magnetization operation is prohibited from starting.

[0040] Step S42: Generate timing linkage instructions. The control logic of actively triggering the start of the subsequent sequence by the end of the preceding sequence is adopted to achieve seamless connection of the three sequences: when the stable segment of the starting sequence runs to the design end time, a trigger signal is immediately output to start the transition segment of the connecting sequence; when the stable segment of the connecting sequence runs to the design end time, a trigger signal is output to start the transition segment of the target sequence; the transmission delay of the trigger signal is controlled within the response accuracy range of the magnetization equipment to ensure that timing deviations will not cause magnetic field interruption or superposition. The gradient magnetic field is output according to the sequence parameters. The initial sequence transition segment increases the magnetic field strength to the stable segment strength according to the designed nonlinear law and maintains it until the trigger signal arrives. The connecting sequence completes the gradual change and stable maintenance of the magnetic field strength according to the quadratic function law, realizing the parameter transition from the surface to the deep layer. The target sequence continues the logic to complete the deep magnetization. The deviation between the magnetic field direction and the easy magnetization direction determined in step S2 throughout the process meets the requirements of continuous magnetic domain orientation.

[0041] Step S43: During the magnetization process, a closed-loop control mechanism is activated to achieve precise parameter control through dual-dimensional monitoring: The first dimension is magnetic field parameter monitoring, where detection elements are arranged at corresponding positions in the surface, middle, and deep layers along the material thickness direction to collect magnetic field strength data in real time and compare it with the sequence design parameters. The deviation is controlled within the allowable range of the magnetization process, which is determined based on the magnetic field distribution logic in step S3. The second dimension is material magnetic response monitoring, where the instantaneous change in the material's permeability is collected through a real-time magnetic performance detection component and compared with the magnetic characteristic distribution data in step S1. If the rate of change exceeds the normal fluctuation range of the material's magnetic characteristics, it is determined to be an abnormal magnetic response. When the magnetic field strength deviation is detected to exceed the allowable range, the control unit immediately fine-tunes the output current of the power module. The adjustment range is proportional to the deviation, and the adjustment response speed matches the requirements of magnetic field parameter changes. When an abnormal magnetic response is detected, the current sequence execution is paused, and the material positioning accuracy and parameter loading accuracy are re-verified. After confirming that there are no errors, the magnetization is restarted from the sequence node before the abnormality to avoid rework of the entire process.

[0042] In this embodiment, sequential timing linkage is achieved through active triggering signals, reducing the connection deviation from the passive response deviation of existing technologies to within the range of equipment control precision, thus ensuring the continuity of the magnetic field. A dual-dimensional monitoring system for magnetic field parameters and material magnetic response is established to achieve real-time correction of parameter deviations. Sequential linkage and closed-loop control ensure that the magnetic field parameters of each region are fully matched with the design, and the residual magnetism deviation of the material surface, middle layer, and deep layer is controlled within the target range of layered magnetization. The dual-dimensional monitoring and real-time intervention mechanism corrects parameter deviations in the magnetization process at the nascent stage, and the abnormal magnetization rate of a single material is controlled within the acceptable range for mass production.

[0043] Based on the same inventive concept as the magnetization method for neodymium iron boron rare earth permanent magnet materials described in the foregoing embodiments, this invention also provides a magnetization device for neodymium iron boron rare earth permanent magnet materials, such as... Figure 2 As shown, the device includes: The parameter acquisition module is used to acquire the magnetic property parameters of the neodymium iron boron material to be magnetized; The sequence matching module is used to match the starting magnetization sequence and the target magnetization sequence from a pre-built multi-parameter adaptive magnetization sequence library based on the magnetic property parameters. A sequence construction module is used to insert a transition sequence between the initial magnetization sequence and the target magnetization sequence, wherein the transition sequence smoothly transitions the magnetic field strength of the magnetization process from the initial level to the target level. The process execution module is used to execute the complete magnetization process consisting of the starting magnetization sequence, the transition sequence, and the target magnetization sequence. The initial magnetization sequence, the target magnetization sequence, and the transition sequence all include a gradient magnetic field magnetization path based on the material thickness and coercivity of the NdFeB material to be magnetized. The gradient magnetic field magnetization path includes a transition magnetization section with nonlinearly increasing magnetic field strength and a stable magnetization section with constant magnetic field strength.

[0044] The device described above in this invention can effectively realize the magnetization method of neodymium iron boron rare earth permanent magnet materials, and the technical effects it can achieve are as described in the above embodiments, which will not be repeated here.

[0045] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of the application as defined herein, and are to be considered as covering any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Thus, if such modifications and modifications fall within the scope of this application and its equivalents, this application intends to include such modifications and modifications.

Claims

1. A method for magnetizing neodymium iron boron rare earth permanent magnet materials, characterized in that, include: Obtain the magnetic property parameters of the neodymium iron boron material to be magnetized; Based on the magnetic property parameters, the starting magnetization sequence and the target magnetization sequence are matched from a pre-built multi-parameter adaptive magnetization sequence library; A transition sequence is inserted between the initial magnetization sequence and the target magnetization sequence to smoothly transition the magnetic field strength of the magnetization process from the initial level to the target level via the transition sequence. The magnetization process consisting of the initial magnetization sequence, the target magnetization sequence, and the transition sequence is executed. The initial magnetization sequence, the target magnetization sequence, and the transition sequence all include a gradient magnetic field magnetization path based on the material thickness and coercivity of the NdFeB material to be magnetized. The gradient magnetic field magnetization path has a transition magnetization section with nonlinear increase in magnetic field strength and a stable magnetization section with constant magnetic field strength.

2. The magnetization method for neodymium iron boron rare earth permanent magnet materials according to claim 1, characterized in that, The magnetic property parameters include at least the material thickness, coercivity, easy magnetization direction, and magnetic property distribution in the thickness direction.

3. The magnetization method for neodymium iron boron rare earth permanent magnet materials according to claim 2, characterized in that, The multi-parameter adaptive magnetization sequence library is generated based on a combination of multiple classification dimensions, including the material's easy magnetization direction angle, thickness range, and residual stress level.

4. The magnetization method for neodymium iron boron rare earth permanent magnet materials according to claim 3, characterized in that, In the process of matching the initial magnetization sequence and the target magnetization sequence, the initial magnetization sequence is preferentially adapted to the surface magnetic properties of the material, and the target magnetization sequence is preferentially adapted to the deep magnetic properties of the material.

5. The magnetization method for neodymium iron boron rare earth permanent magnet materials according to claim 4, characterized in that, The rate of change of magnetic field strength of the transition sequence is derived from the rate of change of magnetic field of the initial magnetization sequence and the target magnetization sequence.

6. The magnetization method for neodymium iron boron rare earth permanent magnet materials according to claim 3, characterized in that, The construction of the multi-parameter adaptive magnetization sequence library includes: Each dimension, including easy magnetization direction angle, thickness range, and residual stress level, is divided into subclasses according to the influence of magnetic properties on magnetization parameters. The boundaries of the subclasses are verified through experiments. Each magnetization sequence corresponds to a subclass combination in the three-dimensional classification system. The sequence parameters are calibrated through orthogonal experiments, and fixed parameters are selected with magnetization uniformity as the optimization objective. The magnetization sequence is stored in the database in an association form between three-dimensional subclass combinations and parameter sets.

7. The magnetization method for neodymium iron boron rare earth permanent magnet materials according to claim 5, characterized in that, Insert abrupt transition sequences, including: Magnetic property parameters of the middle layer region are extracted from the magnetic property distribution data in the thickness direction. The parameters of the transition sequence are calculated based on the parameters of the initial magnetization sequence, the target magnetization sequence, and the magnetic property parameters of the middle layer. The parameters of the transition sequence include the initial magnetic field strength, nonlinear variation coefficient, and final magnetic field strength of the transition magnetization segment, as well as the magnetic field strength and duration of the stable magnetization segment.

8. The magnetization method for neodymium iron boron rare earth permanent magnet materials according to claim 7, characterized in that, The initial magnetic field strength is adopted from the stable segment magnetic field strength of the initial magnetization sequence, the final magnetic field strength is adopted from the initial magnetic field strength of the transition segment of the target magnetization sequence, the nonlinear variation coefficient is obtained by combining the variation coefficients of the initial and target sequences using the weighted average method of the middle layer permeability, the stable segment magnetic field strength is determined based on the average coercivity of the middle layer, and the stable magnetization time is determined based on the average residual stress of the middle layer.

9. The magnetization method for neodymium iron boron rare earth permanent magnet materials according to claim 8, characterized in that, The method for determining the magnetic property parameters of the middle layer region includes: At least three detection nodes are selected in the middle layer region along the material thickness direction, corresponding to the near-surface, center and near-deep layers of the middle layer, respectively; Extract the coercivity, permeability and residual stress parameters of each node, and calculate the average coercivity, average permeability and average residual stress of the middle layer.

10. A magnetizing device for neodymium iron boron rare earth permanent magnet materials, characterized in that, include: The parameter acquisition module is used to acquire the magnetic property parameters of the neodymium iron boron material to be magnetized; The sequence matching module is used to match the starting magnetization sequence and the target magnetization sequence from a pre-built multi-parameter adaptive magnetization sequence library based on the magnetic property parameters. A sequence construction module is used to insert a transition sequence between the initial magnetization sequence and the target magnetization sequence, wherein the transition sequence smoothly transitions the magnetic field strength of the magnetization process from the initial level to the target level. The process execution module is used to execute the complete magnetization process consisting of the starting magnetization sequence, the transition sequence, and the target magnetization sequence. The initial magnetization sequence, the target magnetization sequence, and the transition sequence all include a gradient magnetic field magnetization path based on the material thickness and coercivity of the NdFeB material to be magnetized. The gradient magnetic field magnetization path includes a transition magnetization section with nonlinearly increasing magnetic field strength and a stable magnetization section with constant magnetic field strength.

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