Generator magnetic steel production process

Abstract

The invention relates to the technical field of magnetic steel, in particular to a generator magnetic steel production process which comprises the following steps: screening qualified magnetic steel blanks, performing constant-temperature pretreatment, and introducing protective gas to prevent oxidation; the cutting thickness is set according to the power gradient of a generator, double-stage grinding is conducted after high-precision cutting, and it is guaranteed that the magnetic sheet is precise and free of cracks; marking a magnetic pole, polishing and cleaning, and carrying out plasma activation treatment; pressurizing and fixing after vacuum gluing, and curing an adhesive layer by gradient heating; performing double-stage special-shaped grinding and real-time ruler control, and cleaning and drying after graded chamfering; a double-layer electroplating process is adopted to enhance corrosion resistance, intelligent grading is performed after multi-dimensional detection, and directional magnetizing is performed to calibrate the direction; and finally, vacuum packaging and traceability information printing are carried out to adapt to generators with different powers, and stable performance of the magnetic steel is guaranteed. According to the process, through cutting and slicing and insulating bonding, eddy current is inhibited, heating is reduced, and irreversible thermal demagnetization is avoided; the adhesive constructs an insulating barrier and consolidates the eddy current suppression effect; all links are precisely controlled, and the size precision, the corrosion resistance and the structural stability of the magnetic steel are improved.

Description

Technical Field

[0001] This invention relates to the field of magnet technology, specifically to a generator magnet manufacturing process. Background Technology

[0002] With the rapid development of new energy vehicles, energy storage power stations, and other fields, the performance requirements for permanent magnets, the core component of new energy generators, are continuously increasing. They not only need excellent magnetic properties but also must be adaptable to the harsh working environment of high-frequency rotation and frequent magnetic field changes, meeting the demands for high efficiency, stability, and long lifespan. Traditional new energy generators mostly adopt an integral permanent magnet structure, but this structure faces insurmountable technical bottlenecks in practical applications. When the integral magnet rotates at high speed, the magnetic field changes generate a large range of eddy currents inside, causing the magnet to heat up rapidly. The magnetic properties of commonly used permanent magnets such as neodymium iron boron are extremely sensitive to temperature; prolonged exposure to high temperatures can easily lead to irreversible thermal demagnetization, directly shortening the magnet's lifespan and reducing the generator's operational reliability.

[0003] To alleviate this problem, the industry has gradually adopted a "cut-and-bond" magnet structure. This method limits the eddy current range by dividing the entire magnet into thin sheets. However, the existing cut-and-bond process still has many shortcomings. In the cutting process, some processes use ordinary cutting equipment with a lack of precise parameter control, resulting in poor surface flatness of the magnetic sheets and easy cracking, which directly affects the magnetic properties. Surface treatment is limited to simple grinding and cleaning without activation treatment, resulting in insufficient adhesive adhesion, easy peeling of the adhesive layer, and unstable insulation between adjacent magnetic sheets. The curing process often uses single-temperature heating, resulting in insufficient curing of the adhesive layer, which easily generates internal stress and causes magnet deformation. The grinding and chamfering process parameters are unreasonable, making it difficult to meet the dimensional accuracy and surface roughness of the magnet, and the edges are prone to chipping. The electroplating process is mostly single-layer electroplating, resulting in poor coating uniformity, weak adhesion, insufficient corrosion resistance, and easy rusting after long-term use. The testing process focuses on a single indicator of magnetic properties and lacks comprehensive testing of multiple dimensions such as dimensional accuracy, coating quality, and insulation performance, making it difficult to guarantee the overall quality of the magnet.

[0004] Furthermore, existing processes lack adaptability to generators of different power ratings, and the cutting thickness is not specifically adjusted, resulting in poor magnet versatility and an inability to fully utilize the operating efficiency of generators with varying power ratings. These issues collectively restrict the performance improvement of new energy generators. Therefore, there is an urgent need for a precise, efficient, and stable generator magnet manufacturing process to overcome the shortcomings of existing technologies and meet the high-performance requirements of new energy generators. Summary of the Invention

[0005] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a manufacturing process for generator magnets.

[0006] (II) Technical Solution A manufacturing process for generator magnets includes the following steps: S1 blank precision screening and pretreatment: Select neodymium iron boron magnet blanks, perform constant temperature pretreatment on the blanks, and keep them in an oven at 100-120℃ for 2-3 hours; S2 gradient thickness cutting and fine grinding: Set the cutting parameters of the cutting machine to a speed of 2800 r / min and a feed rate of 4 mm / min, and use rust-preventive cutting fluid for circulating cooling; after cutting, use a double-end grinding machine with a speed of 1450 r / min and a 160-mesh resin grinding wheel for rough grinding, and then switch to an 800-mesh diamond grinding wheel for fine grinding. S3 Magnetic Pole Positioning and Surface Activation Treatment: The original magnetic pole direction of the magnetic sheet is identified and marked by a magnetic pole positioning calibration device; it is first sanded, then ultrasonically cleaned with alcohol; and finally, plasma activation is performed. S4 Vacuum Coating and Gradient Curing: Arrange the magnetic sheets neatly according to the marked magnetic pole directions, place them in a vacuum coating equipment, and evenly apply high-temperature resistant epoxy resin adhesive; fix them with stainless steel clamps, and place them in an oven for gradient temperature curing; the coating method is spray coating, and the adhesive layer thickness is controlled at 0.05-0.1 mm; S5 Dual-Stage Profile Grinding: A dual-stage grinding process is performed using a profile grinding machine. The first stage uses a 300-grit diamond grinding wheel for rough grinding, and the second stage uses a 1000-grit diamond grinding wheel for fine grinding. Rust-preventive cutting fluid is used for cooling, and an OMM image tester monitors dimensional accuracy in real time. S6 graded chamfering and ultrasonic cleaning: A vibratory chamfering machine is used to perform graded speed chamfering; after chamfering, the surface is placed in an ultrasonic cleaner and NaNO2 rust inhibitor is added to remove residual abrasive and rust inhibitor residue. S7 Double-Layer Electroplating and Corrosion Protection: Employs a pre-plating plus main plating process; the pre-plating nickel layer thickness in the pre-plating stage is 1-2μm; the main plating nickel layer thickness in the main plating stage is 5-8μm; the electroplating solution consists of nickel sulfate, nickel chloride, and boric acid; S8 Dynamic Performance Testing: Dimensional accuracy was tested using an OMM image measuring instrument; coating thickness was tested using a film thickness gauge; salt spray test was performed using a salt spray chamber; dynamic magnetic performance was tested using a fluxmeter; and insulation resistance between magnetic sheets was tested using an insulation resistance tester. S9 CCD Intelligent Bin Sorting and Directional Magnetization: The CCD vision sorting system classifies magnets into Grade A, Grade B, and Grade C according to magnetic performance parameters, magnetic flux density, and insulation resistance, and stores them in graded categories; a pulse magnetizer is used for directional magnetization. S10 Vacuum Packaging and Traceability Marking: Place the magnetized magnet into a vacuum packaging bag, evacuate to ≤5 Pa, and then seal; print a traceability code on the surface of the packaging bag, including the batch number of the raw material, the production date, and the test results.

[0007] Preferably, the blank size in S1 is 53.0×48.4×32.6 mm, and the density is 7.5-7.7 g / cm³. 3 The magnetic properties parameters meet the requirements of Br = 12.8-13.2 KGs, Hcj ≥ 14 koe, BHmax = 40-43 KGOe, squareness ≥ 97%, and the isothermal pretreatment is carried out in a nitrogen protective atmosphere with nitrogen purity ≥ 99.9%.

[0008] Preferably, in S2, a gradient thickness cutting scheme is adopted according to the generator power requirements: when the rated power of a high-power motor is ≥60 KW, it is cut into a 2-4 mm thin magnetic sheet; when the rated power of a medium-power motor is 30-60 KW, it is cut into a 4-6 mm magnetic sheet; and when the rated power of a low-power motor is ≤30 KW, it is cut into a 6-10 mm magnetic sheet. Before the gradient thickness cutting, the blank is positioned by a 90° right-angle block and a dial indicator with a resolution of 0.01 mm.

[0009] Preferably, the plasma activation treatment in S3 has a power of 80-100 W and a treatment time of 30-60 s. The working gas is argon or a mixture of argon and oxygen, wherein the ratio of argon to oxygen in the mixture is 9:1.

[0010] Preferably, the high-temperature resistant epoxy resin adhesive in S4 is a combination of E-51 epoxy resin and T31 curing agent or DELOMONOPOXSJ2981 adhesive, with the former having a mixing ratio of 10:1 and the latter having a heat resistance ≥150℃; the gradient temperature curing is performed by holding at 80℃ for 1 h, at 100℃ for 2 h, and at 120℃ for 1 h.

[0011] Preferably, in S5, the first stage grinding wheel specifications are D180 mm, the rotation speed is 2850 r / min, and the guide rail width is 6.04 mm. After the second stage grinding, the magnet size reaches 6.02×48.4×1.35×30°±0.5°×0.7+0.03 / -0.01 mm, and the surface roughness Ra≤0.8μm. The grinding wheel feed rate of the two-stage irregular grinding adopts closed-loop control, which is fed back in real time through a grating ruler with a resolution of 0.001 mm and an adjustable feed speed of 0.01-0.03 mm / s.

[0012] Preferably, the electroplating solution formula in S7 includes 200-250 g / L nickel sulfate, 30-40 g / L nickel chloride, 30-40 g / L boric acid, and 0.1-0.2 g / L brightener to improve the smoothness of the plating layer.

[0013] Preferably, the temperature simulation range for dynamic magnetic performance detection in S8 is -40 to 150°C, covering the extreme operating temperature environment of the generator.

[0014] Preferably, the magnetizing magnetic field strength in S9 is 2000 kA / m, and the magnetizing head for directional magnetization adopts a customized magnetic pole structure that is completely fitted to the irregular surface of the magnet.

[0015] Preferably, in S10, the vacuum packaging bag contains silica gel desiccant, with a dosage of 4-6g / bag. The magnets produced by this process have a service life that is 3-4 times longer, and the magnetic performance attenuation rate is ≤5% at 150℃.

[0016] (iii) Beneficial technical effects Compared with existing technologies, the beneficial effects of this invention are: 1. By precisely selecting the blanks and performing constant-temperature pretreatment, defects caused by material issues during subsequent processing are effectively avoided, laying a solid foundation for the overall quality of the magnets. The cutting process employs a gradient thickness design and high-precision cutting equipment, combined with precise parameter control. This not only significantly improves the surface flatness of the magnetic sheets and reduces crack formation, but also allows for targeted adjustment of the magnetic sheet thickness according to the needs of generators with different power outputs, significantly enhancing the versatility of the process.

[0017] 2. The organic combination of surface activation treatment with vacuum coating and gradient curing processes not only enhances the surface activity of the magnetic sheets and the adhesion of the adhesive, ensuring a uniform and bubble-free adhesive layer, but also achieves full curing of the adhesive layer, avoiding magnet deformation caused by internal stress. This results in strong magnet bonding and structural stability, while also strengthening the insulation effect between adjacent magnetic sheets, further suppressing eddy current flow across the sheets. The application of two-stage irregular grinding and graded chamfering processes effectively improves the dimensional accuracy and surface finish of the magnets, preventing edge chipping and ensuring the appearance integrity and structural stability of the magnets.

[0018] 3. The double-layer electroplating process and optimized electroplating solution formula significantly improve the uniformity and adhesion of the coating, enhance the corrosion resistance of the magnets, and enable them to work stably in complex environments. A multi-dimensional dynamic performance testing system and CCD intelligent binning and directional magnetization process ensure that all magnet indicators meet design requirements, resulting in consistent magnetic pole orientation and stable performance. Attached Figure Description

[0019] Figure 1 This is a flowchart of the production process of generator magnets disclosed in this invention; Figure 2 This is a line graph comparing the reduction in eddy current heating and the overall operating efficiency of the embodiment and the comparative example; Figure 3 This is a bar chart comparing the magnetic performance attenuation rate at 150℃ and the ratio of the no-load current to the rated current of the whole machine between the embodiment and the comparative example. Figure 4 This is a radar comparison chart created by standardizing the dimensions of the performance comparison data of the examples and comparative examples. Detailed Implementation

[0020] according to Figures 1 to 4 The specific embodiments of the present invention are as follows: The following detailed description of the generator magnet production process of the present invention is provided in conjunction with specific embodiments and comparative examples. The equipment models and material parameters mentioned are merely illustrative descriptions and do not constitute a limitation on the scope of protection of the present invention.

[0021] Example 1 S1 blank preforms were precisely screened and pretreated: blanks with dimensions of 53.0×48.4×32.6 mm and a density of 7.5-7.7 g / cm³ were selected. 3 The neodymium iron boron magnet blanks were tested using a magnetic performance tester. The results showed Br = 12.8-13.2 KGs, Hcj ≥ 14 koe, BHmax = 40-43 KGOe, and squareness ≥ 97%, with a total of 2592 blanks produced. The selected blanks were then placed in a nitrogen-protected oven with a nitrogen purity ≥ 99.9%, set at 110℃, and held for 2.5 hours. During this time, nitrogen was continuously introduced to purge air from the oven, preventing oxidation of the blanks and thoroughly removing residual moisture.

[0022] S2 Gradient Thickness Cutting and Precision Grinding: A J5060C-2 high-precision diamond wire cutting machine, adapted to a 60KW medium-power generator, is used. The cutting thickness is set to 4-6 mm. Before cutting, the blank is positioned using a 90° right-angle block, and the perpendicularity of the blank is calibrated using a dial indicator with a resolution of 0.01 mm, with an error ≤0.01 mm. Cutting parameters are set as follows: rotation speed 2800 r / min, feed rate 4 mm / min, D245×D90×0.28 mm diamond cutting inserts are installed, the rust-preventive cutting fluid circulation system is started, the cutting fluid is evenly covered on the cutting surface, and the cutting gap is controlled at 0.3 mm. After cutting, the magnetic sheet is immediately transferred to an M7625-B double-end grinding machine. First, a 160-mesh resin grinding wheel is installed and rough grinding is performed at a speed of 1450 r / min to remove cutting marks. Then, an 800-mesh diamond grinding wheel is used for fine grinding. During this process, the thickness of the magnetic sheet is monitored in real time with a micrometer with a resolution of 0.01 mm. Finally, the magnetic sheet is detected by an ultrasonic flaw detector with an accuracy of 0.01 mm, and any magnetic sheets with cracks are rejected.

[0023] S3 Magnetic Pole Positioning and Surface Activation Treatment: The finely ground magnetic sheet is placed in a magnetic pole positioning and calibration device. This device identifies the original magnetic pole orientation of the magnetic sheet through magnetic field induction and marks it with a laser on the edge of the magnetic sheet to prevent magnetic pole reversal during subsequent arrangement. Surface treatment is then performed: First, the surface of the magnetic sheet is unidirectionally polished with 1000-grit sandpaper at a pressure controlled at 0.3-0.5 N to remove burrs generated during cutting. Next, the magnetic sheet is placed in an ultrasonic cleaner with 95% pure alcohol added. The ultrasonic power is set to 300 W and the cleaning time to 18 minutes. After cleaning, the sheet is removed and allowed to air dry naturally. Finally, the magnetic sheet is placed in a plasma treatment device, with pure argon gas introduced as the working gas. The power is set to 90 W and the treatment time to 45 seconds. During the treatment, the gas pressure inside the device is kept stable to enhance the surface activity of the magnetic sheet.

[0024] S4 Vacuum Coating and Gradient Curing: Arrange the surface-activated magnetic sheets neatly on the stage of the vacuum coating equipment according to the laser-marked magnetic poles. Close the equipment door, start the vacuum pump to evacuate to 10 Pa, and maintain the vacuum state for 5 minutes. Mix E-51 epoxy resin and T31 curing agent evenly in a 10:1 ratio. Apply the mixture evenly to the contact surfaces of the magnetic sheets using a spray nozzle, controlling the coating pressure at 0.3 MPa. The adhesive layer thickness should be 0.05-0.1 mm, without accumulation or bubbles. After coating, use stainless steel clamps to apply 0.8 MPa pressure from both sides of the magnetic sheets to fix them in place. Transfer them to a programmable oven and execute a gradient temperature curing program: first, increase the temperature to 80℃ at a rate of 5℃ / min and hold for 1 hour; then increase the temperature to 100℃ at a rate of 3℃ / min and hold for 2 hours; finally, increase the temperature to 120℃ at a rate of 2℃ / min and hold for 1 hour, for a total curing time of 4 hours. After curing, allow the mixture to cool naturally to room temperature before removing the clamps.

[0025] S5 Two-Stage Irregular Grinding: The cured magnet assembly is fixed on the fixture of the irregular grinding machine. In the first stage, a 300-grit diamond wheel with a diameter of 180 mm is installed. The rotation speed is set to 2850 r / min and the guide rail width is 6.04 mm. The machine is started for rough grinding to remove excess adhesive layer and surface protrusions after bonding. During the rough grinding process, rust-preventive cutting fluid is used for continuous cooling. After the rough grinding is completed, a 1000-grit diamond wheel is replaced for fine grinding. The OMM image tester is turned on to monitor the magnet size in real time with a resolution of 0.001 mm. The feed speed of the grinding wheel is adjusted to 0.02 mm / s. After grinding, the magnet size reaches 6.02×48.4×1.35×30°±0.5°×0.7+0.03 / -0.01 mm, the surface roughness Ra≤0.8μm, and the grinding efficiency is controlled at 1500 pcs / h.

[0026] S6 Graded Chamfering and Ultrasonic Cleaning: Place the irregularly shaped, ground magnets into a 150L PV type vibratory chamfering machine. Add 12×12 oblique triangular silicon carbide abrasive stones at a ratio of 5:1 (grind stone to magnet), with a total load of 75 kg. Add a 1.2% NaNO2 rust inhibitor, ensuring the liquid level covers the magnets and abrasive stones. Set the chamfering machine speed program: 30 Hz for 2 hours → 33 Hz for 2 hours → 35 Hz for 2 hours → 37 Hz for 2 hours, adjusting the amplitude to 2 mm. Regularly observe the equipment's operating status during the chamfering process to avoid material jamming. After chamfering, immediately transfer the magnets to an ultrasonic cleaner. Add clean water and 0.5% neutral cleaning agent, set the ultrasonic power to 300 W, and the cleaning time to 20 minutes to remove residual abrasive debris and rust inhibitor. After cleaning, dry with hot air at 60℃ for 10 minutes.

[0027] S7 Double-Layer Electroplating and Corrosion Protection: Electroplating is performed using an automated barrel plating production line. The electroplating solution formula is 220 g / L nickel sulfate, 35 g / L nickel chloride, and 35 g / L boric acid, with 0.15 g / L brightener added. After thorough stirring, the electroplating solution temperature is raised to 45°C via a heating element. A magnet is placed in an electroplating basket as the cathode, and a pure nickel plate as the anode, both placed in the electroplating tank. The current density is set to 1.5 A / dm³. 2 Pre-plating for 20 minutes forms a 1-2 μm thick nickel layer. After pre-plating, the electroplating bath temperature is raised to 55°C, and the current density is adjusted to 2.5 A / dm³. 2 The main plating process takes 60 minutes to form a 5-8 μm thick nickel plating layer. During the electroplating process, the filter pump is turned on to continuously stir the solution, ensuring uniform concentration of the electroplating solution. At the same time, the side reactions are suppressed by adjusting the current stability to avoid excessive generation of hydrogen and oxygen.

[0028] S8 Dynamic Performance Testing: A multi-dimensional testing system is adopted: ① The size of each magnet is inspected piece by piece using an OMM image measuring instrument, with an error ≤ ±0.02 mm; ② The coating thickness is measured using a film thickness gauge, within the range of 5-8 μm; ③ The magnets are placed in a salt spray test chamber for 72 h of neutral salt spray testing, and the coating shows no wrinkling, peeling, or corrosion; ④ The magnets are installed on a simulated rotating test bench, with a set speed of 10000 r / min, and the dynamic magnetic flux density is measured using a fluxmeter, with an error ≤ 2%; ⑤ The insulation resistance between the magnets is measured using an insulation resistance tester, with an error ≥ 100 MΩ; ⑥ The magnets are assembled onto the rotor of a 60KW generator, and the whole machine is tested under no-load conditions, with no-load current ≤ 8% of the rated current and efficiency ≥ 90%.

[0029] S9 CCD Intelligent Bin Sorting and Directional Magnetization: Qualified magnets are placed into the CCD vision sorting system. The system automatically classifies them into three grades: A, B, and C, based on the results of magnetic flux density and insulation resistance tests. Grade A standards are: magnetic flux density error ≤1%, insulation resistance ≥150 MΩ; Grade B standards are: magnetic flux density error 1%-2%, insulation resistance 100-150 MΩ; Grade C standards are: magnetic flux density error ≤2%, insulation resistance ≥100 MΩ. The magnets are then stored in different bins according to their grade. Grade A magnets are placed into a pulse magnetizer. A customized magnetizing head that perfectly fits the irregular surface of the magnet is selected. The magnetizing magnetic field strength is set to 2000 kA / m, and the magnetizing direction is calibrated to align with the magnetic poles marked on the magnetic sheet. The magnetizer is then started to complete the directional magnetization.

[0030] S10 Vacuum Packaging and Traceability Marking: Magnetized magnets are packed into vacuum packaging bags of 50 pieces each, along with 5 g / bag of silica gel desiccant. The bags are then placed in a vacuum packaging machine, evacuated to 5 Pa, and heat-sealed. A traceability code containing the batch number, production date, test results, and bin number is generated through the traceability system and printed on the surface of the packaging bag using a laser printer, facilitating quality traceability during subsequent warehousing, transportation, and use.

[0031] Example 2 S1 blank preforms were precisely screened and pretreated: blanks with dimensions of 53.0×48.4×32.6 mm and a density of 7.6-7.7 g / cm³ were selected. 3 The neodymium iron boron magnet blanks were tested using a magnetic performance tester. The results showed Br = 13.0-13.2 KGs, Hcj ≥ 14 koe, BHmax = 42-43 KGOe, and squareness ≥ 97%, with a total of 2592 blanks produced. The blanks were placed in a nitrogen-protected oven at 120℃ for 2 hours. The nitrogen purity was ≥ 99.9%. During this time, nitrogen was continuously introduced to purge air from the oven, preventing oxidation of the blanks and thoroughly removing residual moisture.

[0032] S2 Gradient Thickness Cutting and Precision Grinding: A J5060C-2 high-precision diamond wire cutting machine, adapted to a 45KW medium-power generator, is used. The cutting thickness is set to 5-6 mm. Before cutting, the blank is positioned using a 90° right-angle block, and the perpendicularity of the blank is calibrated using a dial indicator with a resolution of 0.01 mm, with an error ≤0.01 mm. Cutting parameters are set as follows: rotation speed 2800 r / min, feed rate 4 mm / min, D245×D90×0.28 mm diamond inserts are installed, the rust-preventive cutting fluid circulation system is started, the cutting fluid is evenly covered on the cutting surface, and the cutting gap is controlled at 0.3 mm. After cutting, the magnetic sheet is immediately transferred to an M7625-B double-end grinding machine. First, a 160-mesh resin grinding wheel is installed, and rough grinding is performed at a speed of 1450 r / min to remove cutting marks. Then, an 800-mesh diamond grinding wheel is used for fine grinding. During this process, a micrometer with a resolution of 0.01 mm is used to detect the thickness of the magnetic sheet in real time. The surface flatness error is ≤0.005 mm. Finally, the magnetic sheet is detected by an ultrasonic flaw detector with an accuracy of 0.01 mm, and any magnetic sheets with cracks are rejected.

[0033] S3 Magnetic Pole Positioning and Surface Activation Treatment: The finely ground magnetic sheet is placed in a magnetic pole positioning and calibration device. This device identifies the original magnetic pole orientation of the magnetic sheet through magnetic field induction and marks it with a laser on the edge of the magnetic sheet to prevent magnetic pole reversal during subsequent arrangement. Surface treatment is then performed: First, the surface of the magnetic sheet is unidirectionally sanded with 1000-grit sandpaper at a pressure controlled at 0.3-0.5 N to remove burrs generated during cutting. Next, the magnetic sheet is placed in an ultrasonic cleaner with 95% pure alcohol added. The ultrasonic power is set to 300 W and the cleaning time to 20 minutes. After cleaning, it is removed and allowed to air dry naturally. Finally, the magnetic sheet is placed in a plasma treatment device, where a mixture of argon and oxygen (9:1 ratio) is introduced. The power is set to 100 W and the treatment time to 60 seconds. During the treatment, the internal pressure of the device is kept stable to increase the hydroxyl content and activity on the surface of the magnetic sheet.

[0034] S4 Vacuum Coating and Gradient Curing: Arrange the surface-activated magnetic sheets neatly on the stage of the vacuum coating equipment according to the laser-marked magnetic poles. Close the equipment door, start the vacuum pump to evacuate to 8 Pa, and maintain the vacuum state for 5 minutes. Select a high-temperature resistant epoxy resin adhesive with a heat resistance of ≥150℃. Apply the adhesive evenly to the contact surface of the magnetic sheets through a spray nozzle, controlling the coating pressure at 0.3 MPa. The adhesive layer thickness should be 0.08-0.1 mm, without accumulation or bubbles. After coating, use stainless steel clamps to apply 1 MPa pressure from both sides of the magnetic sheets to fix them. Transfer them to a programmable oven and execute a gradient temperature curing program: first, increase the temperature to 80℃ at a rate of 5℃ / min and hold for 1 hour; then increase the temperature to 100℃ at a rate of 3℃ / min and hold for 2 hours; finally, increase the temperature to 120℃ at a rate of 2℃ / min and hold for 1 hour, for a total curing time of 4 hours. After curing, allow it to cool naturally to room temperature before removing the clamps.

[0035] S5 Two-Stage Irregular Grinding: The cured magnet assembly is fixed on the fixture of the irregular grinding machine. In the first stage, a 300-grit diamond wheel with a diameter of 180 mm is installed. The rotation speed is set to 2850 r / min and the guide rail width is 6.04 mm. The machine is started for rough grinding to remove excess adhesive and surface protrusions. During the rough grinding process, rust-preventive cutting fluid is used for continuous cooling. After the rough grinding is completed, a 1000-grit diamond wheel is replaced for fine grinding. The wheel feed rate is controlled by a closed loop. The grating ruler with a resolution of 0.001 mm provides real-time feedback of the size data. The feed speed is automatically adjusted to 0.02-0.03 mm / s. An OMM image measuring instrument with a resolution of 0.001 mm is turned on to monitor the magnet size in real time. After grinding, the magnet size reaches 6.02×48.4×1.35×30°±0.5°×0.7+0.03 / -0.01 mm, the surface roughness Ra≤0.8μm, and the grinding efficiency is controlled at 1500 pcs / h.

[0036] S6 Graded Chamfering and Ultrasonic Cleaning: Place the irregularly shaped, ground magnets into a 150L PV type vibratory chamfering machine. Add 12×12 oblique triangular silicon carbide abrasive stones at a ratio of 5:1 (grind stone to magnet), with a total load of 75 kg. Add 1.0% NaNO2 rust inhibitor, ensuring the liquid level covers the magnets and abrasive stones. Set the chamfering machine speed program: 30 Hz for 2 hours → 33 Hz for 2 hours → 35 Hz for 2 hours → 37 Hz for 2 hours. Adjust the amplitude to 3 mm and the chamfering angle to R0.12-R0.15. Regularly observe the equipment's operating status during the chamfering process to avoid material jamming. After chamfering, immediately transfer the magnets to an ultrasonic cleaner. Add clean water and 0.5% neutral cleaning agent. Set the ultrasonic power to 300 W and the cleaning time to 20 minutes to remove residual abrasive debris and rust inhibitor from the surface. After cleaning, dry with hot air at 65℃ for 8 minutes.

[0037] S7 Double-Layer Electroplating and Corrosion Protection: Electroplating is performed using an automated barrel plating production line. The electroplating solution formula is 250 g / L nickel sulfate, 40 g / L nickel chloride, and 40 g / L boric acid, with 0.2 g / L brightener added. After thorough stirring, the electroplating solution temperature is raised to 48℃ via a heating element. A magnet is placed in an electroplating basket as the cathode, and a pure nickel plate as the anode, both placed in the electroplating tank. The current density is set to 2 A / dm³. 2 Pre-plating was performed for 18 minutes to form a 1-2 μm thick nickel layer. After pre-plating, the electroplating solution temperature was raised to 60°C, and the current density was adjusted to 3 A / dm³. 2 The main plating process lasts 55 minutes, forming a 5-8 μm thick nickel plating layer. During the electroplating process, the filter pump is turned on to continuously stir the solution, ensuring uniform concentration of the electroplating solution. At the same time, the side reactions are suppressed by adjusting the current stability to avoid excessive generation of hydrogen and oxygen.

[0038] S8 Dynamic Performance Testing: A multi-dimensional testing system is adopted: ① The size of each magnet is inspected using an OMM image measuring instrument, with an error ≤ ±0.02 mm; ② The coating thickness is measured using a film thickness gauge, within the range of 5-8 μm; ③ The magnets are placed in a salt spray test chamber for 72 h of neutral salt spray testing, and the coating shows no wrinkling, peeling, or corrosion; ④ The magnets are installed on a simulated rotating test bench, with a set rotation speed of 10000 r / min and a simulated temperature range of -40-150℃, and the dynamic magnetic flux density is measured using a fluxmeter, with an error ≤2%; ⑤ The insulation resistance between the magnet sheets is measured using an insulation resistance tester, ≥100 MΩ; ⑥ The magnets are assembled onto the rotor of a 45KW generator, and the whole machine is tested under no-load conditions, with no-load current ≤ 7% of the rated current and efficiency ≥ 91%.

[0039] S9 CCD Intelligent Bin Sorting and Directional Magnetization: Qualified magnets are placed into the CCD vision sorting system. The system automatically classifies them into three grades: A, B, and C, based on the results of magnetic flux density and insulation resistance tests. Grade A standards are: magnetic flux density error ≤1%, insulation resistance ≥150 MΩ; Grade B standards are: magnetic flux density error 1%-2%, insulation resistance 100-150 MΩ; Grade C standards are: magnetic flux density error ≤2%, insulation resistance ≥100 MΩ. The magnets are then stored in different bins according to their grade. Grade A magnets are placed into a pulse magnetizer. A customized magnetizing head that perfectly fits the irregular surface of the magnet is selected. The magnetizing magnetic field strength is set to 2200 kA / m, and the magnetizing direction is calibrated to align with the magnetic poles marked on the magnetic sheet. The magnetizer is then started to complete the directional magnetization.

[0040] S10 Vacuum Packaging and Traceability Marking: Magnetized magnets are packed into vacuum packaging bags of 40 pieces each, along with 6 g / bag of silica gel desiccant. The bags are then placed in a vacuum packaging machine, evacuated to 4 Pa, and heat-sealed. A traceability code is generated through the traceability system, containing the batch number of the raw material, production date, test results, bin grade, and electroplating parameters. This code is printed on the surface of the packaging bag using a laser printer, facilitating quality traceability during subsequent warehousing, transportation, and use.

[0041] Example 3 S1 blank preforms were precisely screened and pretreated: blanks with dimensions of 53.0×48.4×32.6 mm and a density of 7.5-7.6 g / cm³ were selected. 3 The neodymium iron boron magnet blanks were tested using a magnetic performance tester. The results showed Br = 12.8-13.0 KGs, Hcj ≥ 15 koe, BHmax = 40-42 KGOe, and squareness ≥ 98%, with a total of 2592 blanks produced. The blanks were placed in a nitrogen-protected oven at 100℃ for 3 hours. The nitrogen purity was ≥ 99.9%. During this time, nitrogen was continuously introduced to purge air from the oven, preventing oxidation and thoroughly removing residual moisture.

[0042] S2 Gradient Thickness Cutting and Precision Grinding: A J5060C-2 high-precision diamond wire cutting machine, equipped with a 75KW high-power generator, is used. The cutting thickness is set to 3-4 mm. Before cutting, the blank is positioned using a 90° right-angle block, and the perpendicularity of the blank is calibrated using a dial indicator with a resolution of 0.01 mm, with an error ≤0.01 mm. Cutting parameters are set as follows: rotation speed 2800 r / min, feed rate 4 mm / min, D245×D90×0.28 mm diamond cutting inserts are installed, the rust-preventive cutting fluid circulation system is started, the cutting fluid is evenly covered on the cutting surface, and the cutting gap is controlled at 0.3 mm. After cutting, the magnetic sheet is immediately transferred to an M7625-B double-end grinding machine. First, a 160-mesh resin grinding wheel is installed and rough grinding is performed at a speed of 1450 r / min to remove cutting marks. Then, an 800-mesh diamond grinding wheel is used for fine grinding. During this process, a micrometer with a resolution of 0.01 mm is used to detect the thickness of the magnetic sheet in real time. The surface flatness error is ≤0.004 mm. Finally, an ultrasonic flaw detector with an accuracy of 0.01 mm is used to detect and remove magnetic sheets with cracks.

[0043] S3 Magnetic Pole Positioning and Surface Activation Treatment: The finely ground magnetic sheet is placed in a magnetic pole positioning and calibration device. This device identifies the original magnetic pole orientation of the magnetic sheet through magnetic field induction and marks it with a laser on the edge of the magnetic sheet to prevent magnetic pole reversal during subsequent arrangement. Surface treatment is then performed: First, the surface of the magnetic sheet is unidirectionally polished with 1000-grit sandpaper at a pressure controlled at 0.3-0.5 N to remove burrs generated during cutting. Next, the magnetic sheet is placed in an ultrasonic cleaner with 95% pure alcohol added. The ultrasonic power is set to 300 W and the cleaning time to 15 minutes. After cleaning, the sheet is removed and allowed to air dry naturally. Finally, the magnetic sheet is placed in a plasma treatment device, with pure argon gas introduced as the working gas. The power is set to 80 W and the treatment time to 30 seconds. During the treatment, the gas pressure inside the device is kept stable to enhance the surface activity of the magnetic sheet.

[0044] S4 Vacuum Coating and Gradient Curing: Arrange the surface-activated magnetic sheets neatly on the stage of the vacuum coating equipment according to the laser-marked magnetic poles. Close the equipment door, start the vacuum pump to evacuate to 9 Pa, and maintain the vacuum state for 5 minutes. Mix E-51 epoxy resin and T31 curing agent evenly in a 10:1 ratio. Apply the mixture evenly to the contact surfaces of the magnetic sheets using a spray nozzle, controlling the coating pressure at 0.3 MPa. The adhesive layer thickness should be 0.05-0.08 mm, without accumulation or bubbles. After coating, use stainless steel clamps to apply 0.5 MPa pressure from both sides of the magnetic sheets to fix them in place. Transfer them to a programmable oven and execute a gradient temperature curing program: first, increase the temperature to 80℃ at a rate of 5℃ / min and hold for 1 hour; then increase the temperature to 100℃ at a rate of 3℃ / min and hold for 2 hours; finally, increase the temperature to 120℃ at a rate of 2℃ / min and hold for 1 hour, for a total curing time of 4 hours. After curing, allow the mixture to cool naturally to room temperature before removing the clamps.

[0045] S5 Two-Stage Irregular Grinding: The cured magnet assembly is fixed on the fixture of the irregular grinding machine. In the first stage, a 300-grit diamond wheel with a diameter of 180 mm is installed. The rotation speed is set to 2850 r / min and the guide rail width is 6.04 mm. The machine is started for rough grinding to remove excess adhesive and surface protrusions. During the rough grinding process, rust-preventive cutting fluid is used for continuous cooling. After the rough grinding is completed, a 1000-grit diamond wheel is replaced for fine grinding. The wheel feed rate is controlled by a closed loop. The grating ruler with a resolution of 0.001 mm provides real-time feedback of the size data. The feed speed is automatically adjusted to 0.01-0.02 mm / s. An OMM image measuring instrument with a resolution of 0.001 mm is turned on to monitor the magnet size in real time. After grinding, the magnet size reaches 6.02×48.4×1.35×30°±0.5°×0.7+0.03 / -0.01 mm, the surface roughness Ra≤0.8μm, and the grinding efficiency is controlled at 1500 pcs / h.

[0046] S6 Graded Chamfering and Ultrasonic Cleaning: Place the irregularly shaped, ground magnets into a 150L PV type vibratory chamfering machine. Add 12×12 oblique triangular silicon carbide abrasive stones at a ratio of 5:1 (grind stone to magnet), with a total load of 75 kg. Add 1.5% NaNO2 rust inhibitor, ensuring the liquid level covers the magnets and abrasive stones. Set the chamfering machine speed program: 30 Hz for 2 hours → 33 Hz for 2 hours → 35 Hz for 2 hours → 37 Hz for 2 hours. Adjust the amplitude to 1.5 mm and the chamfering angle to R0.1-R0.12. Regularly observe the equipment's operating status during the chamfering process to avoid material jamming. After chamfering, immediately transfer the magnets to an ultrasonic cleaner. Add clean water and 0.5% neutral cleaning agent. Set the ultrasonic power to 300 W and the cleaning time to 20 minutes to remove residual abrasive debris and rust inhibitor. After cleaning, dry with hot air at 55℃ for 12 minutes.

[0047] S7 Double-Layer Electroplating and Corrosion Protection: Electroplating is performed using an automated barrel plating production line. The electroplating solution formula is 200 g / L nickel sulfate, 30 g / L nickel chloride, and 30 g / L boric acid, with 0.1 g / L brightener added. After thorough stirring, the temperature of the electroplating solution is raised to 40°C via a heating element. A magnet is placed in an electroplating basket as the cathode, and a pure nickel plate is placed as the anode in the electroplating tank. The current density is set to 1 A / dm³. 2 Pre-plating for 25 minutes forms a 1-2 μm thick nickel layer. After pre-plating, the electroplating bath temperature is raised to 50°C, and the current density is adjusted to 2 A / dm³. 2 The main plating process takes 70 minutes to form a 5-8 μm thick nickel plating layer. During the electroplating process, the filter pump is turned on to continuously stir the solution, ensuring uniform concentration of the electroplating solution. At the same time, the side reactions are suppressed by adjusting the current stability to avoid excessive generation of hydrogen and oxygen.

[0048] S8 Dynamic Performance Testing: A multi-dimensional testing system is adopted: ① The size of each magnet is inspected piece by piece using an OMM image measuring instrument, with an error ≤ ±0.02 mm; ② The coating thickness is measured using a film thickness gauge, within the range of 5-8 μm; ③ The magnets are placed in a salt spray test chamber for 72 h of neutral salt spray testing, and the coating shows no wrinkling, peeling, or corrosion; ④ The magnets are installed on a simulated rotating test bench, with a set speed of 12000 r / min, and the dynamic magnetic flux density is measured using a fluxmeter, with an error ≤ 1.8%; ⑤ The insulation resistance between the magnet pieces is measured using an insulation resistance tester, ≥ 120 MΩ; ⑥ The magnets are assembled onto the rotor of a 75KW generator, and the whole machine is tested under no-load conditions, with no-load current ≤ 7.5% of the rated current and efficiency ≥ 90.5%.

[0049] S9 CCD Intelligent Bin Sorting and Directional Magnetization: Qualified magnets are placed into the CCD vision sorting system. The system automatically classifies them into three grades: A, B, and C, based on the results of magnetic flux density and insulation resistance tests. Grade A standards are: magnetic flux density error ≤1%, insulation resistance ≥150 MΩ; Grade B standards are: magnetic flux density error 1%-2%, insulation resistance 100-150 MΩ; and Grade C standards are: magnetic flux density error ≤2%, insulation resistance ≥100 MΩ. The magnets are then stored in different bins according to their grade. Grade A magnets are placed into a pulse magnetizer. A customized magnetizing head that perfectly fits the irregular surface of the magnet is selected. The magnetizing magnetic field strength is set to 2300 kA / m, and the magnetizing direction is calibrated to align with the magnetic poles marked on the magnetic sheet. The magnetizer is then started to complete the directional magnetization.

[0050] S10 Vacuum Packaging and Traceability Marking: Magnetized magnets are packed into vacuum packaging bags of 60 pieces each, along with 4 g / bag of silica gel desiccant. The bags are then placed in a vacuum packaging machine, evacuated to 5 Pa, and heat-sealed. A traceability code is generated through the traceability system, containing the batch number of the raw material, production date, test results, bin classification, and high-power compatibility identifier. This code is printed on the surface of the packaging bag using a laser printer, facilitating quality traceability during subsequent warehousing, transportation, and use.

[0051] Comparative Example Preparation of S1 blank: Select blanks with dimensions of 53.0×48.4×32.6 mm and a density of 7.5-7.7 g / cm³. 3 The neodymium iron boron magnet blanks were tested with a magnetic performance tester. The results showed that Br was 12.8-13.2 KGs, Hcj ≥ 14 koe, BHmax was 40-43 KGOe, and squareness was ≥ 97%. A total of 2592 blanks were produced. No constant temperature pretreatment or nitrogen protection was performed. The blanks were directly put into processing.

[0052] S2 Cutting and Grinding: A J5060C diamond wire cutting machine with a non-gradient thickness design was used to cut 6 mm thick magnetic sheets. Before cutting, a 90° right-angle guide block was used for positioning; no dial indicator was used to calibrate the perpendicularity. Cutting parameters were set as follows: spindle speed 2600 r / min, feed rate 5 mm / min, D245×D90×0.28 mm diamond inserts, rust-preventive cutting fluid for cooling, and a kerf of 0.35 mm. After cutting, a standard double-end face grinder with a 400-grit resin wheel was used for a single grinding pass at 1400 r / min. The magnetic sheet thickness was checked with a micrometer; the surface flatness error was ≤0.01 mm. An ultrasonic flaw detector was used with a detection accuracy of 0.02 mm. Magnetic sheets with obvious cracks were discarded.

[0053] S3 Surface Treatment and Magnetic Pole Positioning: The magnetic pole direction of the magnetic sheet is marked by a simple magnetic pole identification device, the cutting burrs are removed by sanding with 800-grit sandpaper, and the sheet is ultrasonically cleaned in water for 15 minutes. No plasma activation treatment is performed. The sheet is then air-dried after cleaning.

[0054] S4 Bonding and Curing: Ordinary epoxy resin adhesive is used and manually applied to the contact surface of the magnetic sheets. The adhesive layer thickness is controlled at 0.1-0.2 mm. Vacuum coating equipment is not available. The magnetic sheets are arranged according to the marked magnetic pole direction and fixed with a stainless steel clamp applying a pressure of 0.5 MPa. They are then placed in an oven and cured at a constant temperature of 100℃ for 3 hours without a gradient temperature rise program.

[0055] S5 Irregular Grinding and Chamfering: A standard irregular grinding machine was used, equipped with a 300-grit diamond wheel, and the rotation speed was set to 2800 r / min for a single irregular grinding operation. Real-time dimensional monitoring was not performed; dimensions were only checked with calipers after grinding, achieving 6.02×48.4×1.35×30°±0.5°×0.7+0.03 / -0.01 mm. Chamfering was performed using a 150L standard vibratory chamfering machine with a grinding stone to magnet ratio of 3:1, a loading capacity of 75 kg, and 12×12 oblique triangular silicon carbide grinding stones. The rotation speed was set to 35 Hz, the amplitude to 3 mm, and the chamfering time to 6 hours. A 1.5% NaNO2 rust inhibitor was added, and the chamfer angle was R0.1-R0.15.

[0056] S6 electroplating: Employs a semi-automatic barrel plating production line with a single-layer electroplating process. The plating solution formula consists of 220 g / L nickel sulfate, 35 g / L nickel chloride, and 35 g / L boric acid, without any brighteners. The temperature is controlled at 50℃, and the current density is 2.5 A / dm³. 2 The electroplating time is 60 minutes, forming a nickel layer with a thickness of 6-8 μm. During the electroplating process, the electroplating solution is uniformly stirred naturally.

[0057] S7 Inspection and Subsequent Processing: Magnet dimensions were measured using calipers, with an error ≤ ±0.03 mm; static magnetic flux density was measured using a fluxmeter, with an error ≤ 3%; insulation resistance between magnetic sheets was measured using an insulation resistance tester, ≥ 80 MΩ; salt spray testing and dynamic performance testing were not performed. There was no CCD binning step; qualified magnets were directly placed into a standard magnetizer, using a universal magnetizing head, with the magnetizing magnetic field strength set to 2000 kA / m to complete magnetization. The magnetized magnets were then placed in a standard sealed bag with silica gel desiccant, sealed, and packaged without traceability markings.

[0058] S8 whole machine test: Assemble the magnets onto the rotor of the 60KW generator and conduct a whole machine no-load test. The no-load current is ≤12% of the rated current and the efficiency is ≥85%.

[0059] The basic performance and process parameters of the examples and comparative examples are compared in the table below: Table 1 Performance / Process Specifications (Units) Example 1 Example 2 Example 3 Comparative Example <![CDATA[毛坯 density (g / cm 3 ).]]> 7.5-7.7 7.6-7.7 7.5-7.6 7.5-7.7 Br value of magnet (KGs) 12.8-13.2 13.0-13.2 12.8-13.0 12.8-13.2 Thickness (mm) 4-6 5-6 3-4 6 Cutting speed (r / min) 2800 2800 2800 2600 Feed rate (mm / min) 4 4 4 5 Surface flatness error of magnetic sheet (mm) 0.005 0.005 0.004 0.01 Adhesive layer thickness (mm) 0.05-0.1 0.08-0.1 0.05-0.08 0.1-0.2 Total curing time (h) 4 4 4 3 Grinding speed for irregular shapes (r / min) 2850 2850 2850 2800 Chamfering and vibratory grinding time (h) 8 8 8 6 Electroplating Double-layer plating (pre-plating + main plating) Double-layer plating (pre-plating + main plating) Double-layer plating (pre-plating + main plating) Single-layer plating <![CDATA[Preplating current density (A / dm 2 )]]> 1.5 2 1 - <![CDATA[Main plating current density (A / dm 2 ).]]> 2.5 3 2 2.5 The performance and long-term stability of the examples and comparative examples are quantitatively compared in the table below: Table 2 Performance indicators Example 1 Example 2 Example 3 Comparative Example Reduction in eddy current heating (%) 60 65 62 30 Magnetic property attenuation rate at 150℃ (%) 5 4 4.5 8 Percentage of rusted area after 72-hour salt spray test (%) 0 0 0 5 Adhesive layer peeling rate (1000h test, %) 0.5 0.3 0.4 3 Coating peeling rate (1000h test, %) 0 0 0 2 Service life extension factor (times) 3-4 3.5-4.5 3-4 1.5-2 The percentage of no-load current to rated current of the entire unit (%) 8 7 7.5 12 Overall machine operating efficiency (%) 90 91 90.5 85 Magnetic property retention rate at extreme temperature (-40℃) (%) 95 96 95.5 90 Magnetic property retention rate at extreme temperature (150℃) (%) 95 96 95.5 92 Magnet dimensional accuracy pass rate (%) 99.5 99.6 99.7 98 In summary, the data in the two tables clearly demonstrate that this patented process achieves significant performance improvements compared to conventional processes through precise control of process parameters at each stage. Regarding process parameters, the embodiment uses fixed and optimized cutting speed, feed rate, and curing time. The surface flatness error of the magnetic sheet is controlled within 0.004-0.005mm, and the adhesive layer thickness is precisely adapted to different power requirements. Combined with a double-layer electroplating process and specific current density parameters, compared to the comparative example's single parameter setting, single-layer electroplating, and shorter curing time, the processing accuracy and process stability are significantly optimized.

[0060] In terms of performance, the embodiment reduces eddy current heating by 60%-65%, the magnetic performance decay rate at 150℃ is only 4%-5%, the peeling rate of adhesive and coating is extremely low, the service life is extended by 3-4.5 times, the overall operating efficiency is maintained above 90%, and the magnetic performance retention rate is over 95% at extreme temperatures; while the comparative embodiment, due to insufficient control of process parameters, reduces heating by only 30%, the magnetic performance decay rate and peeling rate are both high, and the service life and operating efficiency are significantly inferior to the patented process.

[0061] Example 2, by optimizing insulation and corrosion protection parameters, showed the best performance in extreme temperature adaptability and shedding rate control. Example 3, by adjusting the cutting thickness and magnetization parameters for high-power scenarios, showed stronger adaptability, fully demonstrating the superiority and adaptability of the process of the present invention in the production of magnets for generators of different power.

[0062] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A manufacturing process for generator magnets, characterized in that, Includes the following steps: S1 blank precision screening and pretreatment: Select neodymium iron boron magnet blanks, perform constant temperature pretreatment on the blanks, and keep them in an oven at 100-120℃ for 2-3 hours; S2 gradient thickness cutting and fine grinding: Set the cutting parameters of the cutting machine to a speed of 2800 r / min and a feed rate of 4 mm / min, and use rust-preventive cutting fluid for circulating cooling; after cutting, use a double-end grinding machine with a speed of 1450 r / min and a 160-mesh resin grinding wheel for rough grinding, and then switch to an 800-mesh diamond grinding wheel for fine grinding. S3 Magnetic Pole Positioning and Surface Activation Treatment: The original magnetic pole direction of the magnetic sheet is identified and marked by a magnetic pole positioning calibration device; it is first sanded, then ultrasonically cleaned with alcohol; and finally, plasma activation is performed. S4 Vacuum Coating and Gradient Curing: Arrange the magnetic sheets neatly according to the marked magnetic pole directions, place them in a vacuum coating equipment, and evenly apply high-temperature resistant epoxy resin adhesive; fix them with stainless steel clamps, and place them in an oven for gradient temperature curing; the coating method is spray coating, and the adhesive layer thickness is controlled at 0.05-0.1 mm; S5 Dual-Stage Profile Grinding: A dual-stage grinding process is performed using a profile grinding machine. The first stage uses a 300-grit diamond grinding wheel for rough grinding, and the second stage uses a 1000-grit diamond grinding wheel for fine grinding. Rust-preventive cutting fluid is used for cooling, and an OMM image tester monitors dimensional accuracy in real time. S6 graded chamfering and ultrasonic cleaning: A vibratory chamfering machine is used to perform graded speed chamfering; after chamfering, the surface is placed in an ultrasonic cleaner and NaNO2 rust inhibitor is added to remove residual abrasive and rust inhibitor residue. S7 Double-Layer Electroplating and Corrosion Protection: Employs a pre-plating plus main plating process; the pre-plating nickel layer thickness in the pre-plating stage is 1-2μm; the main plating nickel layer thickness in the main plating stage is 5-8μm; the electroplating solution consists of nickel sulfate, nickel chloride, and boric acid; S8 Dynamic Performance Testing: Dimensional accuracy was tested using an OMM image measuring instrument; coating thickness was tested using a film thickness gauge; salt spray test was performed using a salt spray chamber; dynamic magnetic performance was tested using a fluxmeter; and insulation resistance between magnetic sheets was tested using an insulation resistance tester. S9 CCD Intelligent Bin Sorting and Directional Magnetization: The CCD vision sorting system classifies magnets into Grade A, Grade B, and Grade C according to magnetic performance parameters, magnetic flux density, and insulation resistance, and stores them in graded categories; a pulse magnetizer is used for directional magnetization. S10 Vacuum Packaging and Traceability Marking: Place the magnetized magnet into a vacuum packaging bag, evacuate to ≤5 Pa, and then seal; print a traceability code on the surface of the packaging bag, including the batch number of the raw material, the production date, and the test results.

2. The generator magnet manufacturing process according to claim 1, characterized in that, The blank size in S1 is 53.0×48.4×32.6 mm, and the density is 7.5-7.7 g / cm³. 3 The magnetic properties parameters meet the requirements of Br = 12.8-13.2 KGs, Hcj ≥ 14 koe, BHmax = 40-43 KGOe, squareness ≥ 97%, and the isothermal pretreatment is carried out in a nitrogen protective atmosphere with nitrogen purity ≥ 99.9%.

3. The generator magnet manufacturing process according to claim 1, characterized in that, S2 adopts a gradient thickness cutting scheme according to the generator power requirements: when the rated power of a high-power motor is ≥60 KW, it is cut into 2-4 mm thin magnetic sheets; when the rated power of a medium-power motor is 30-60 KW, it is cut into 4-6 mm magnetic sheets; when the rated power of a low-power motor is ≤30 KW, it is cut into 6-10 mm magnetic sheets. Before gradient thickness cutting, the blank is positioned by a 90° right-angle block and a dial indicator with a resolution of 0.01 mm.

4. The generator magnet manufacturing process according to claim 1, characterized in that, The plasma activation treatment in S3 has a power of 80-100 W and a treatment time of 30-60 s. The working gas is argon or a mixture of argon and oxygen, wherein the ratio of argon to oxygen in the argon-oxygen mixture is 9:

1.

5. The generator magnet manufacturing process according to claim 1, characterized in that, The high-temperature resistant epoxy resin adhesive in S4 is a combination of E-51 epoxy resin and T31 curing agent or DELOMONOPOX SJ2981 adhesive. The former has a mixing ratio of 10:1, and the latter has a heat resistance of ≥150℃. The gradient temperature curing is performed by holding at 80℃ for 1 h, 100℃ for 2 h, and 120℃ for 1 h.

6. The generator magnet manufacturing process according to claim 1, characterized in that, In the S5, the first stage grinding wheel specifications are D180 mm, the rotation speed is 2850 r / min, and the guide rail width is 6.04 mm. After the second stage grinding, the magnet size reaches 6.02×48.4×1.35×30°±0.5°×0.7+0.03 / -0.01 mm, and the surface roughness Ra≤0.8μm. The grinding wheel feed rate of the two-stage irregular grinding adopts closed-loop control, which is fed back in real time through a grating ruler with a resolution of 0.001 mm and an adjustable feed speed of 0.01-0.03 mm / s.

7. The generator magnet manufacturing process according to claim 1, characterized in that, The electroplating solution formula in S7 contains 200-250 g / L nickel sulfate, 30-40 g / L nickel chloride, and 30-40 g / L boric acid, with 0.1-0.2 g / L of brightener added to improve the smoothness of the plating layer.

8. The generator magnet manufacturing process according to claim 1, characterized in that, The temperature simulation range for dynamic magnetic performance detection in S8 is -40 to 150℃, covering the extreme operating temperature environment of the generator.

9. The generator magnet manufacturing process according to claim 1, characterized in that, The S9 has a magnetizing magnetic field strength of 2000kA / m, and the magnetizing head for directional magnetization adopts a customized magnetic pole structure that fits perfectly with the irregular surface of the magnet.

10. The generator magnet manufacturing process according to claim 1, characterized in that, The S10 vacuum packaging bag contains silica gel desiccant, with a dosage of 4-6 g / bag. Magnets produced by this process have a service life that is 3-4 times longer, and the magnetic performance decay rate is ≤5% at 150℃.

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