Silicon steel-amorphous composite material for motor core and its preparation and application

Abstract

The present invention relates to the technical field of motor magnetic circuit components, and provides a silicon steel-amorphous composite material for motor core and its preparation and application, comprising: 70～90 Si 5～12 B 8～15 A series of targets are magnetron sputtered onto the surface of pretreated silicon steel sheets to produce a silicon-steel-amorphous composite material with an amorphous layer 100 to 1000 nm thick. This silicon-steel-amorphous composite material combines the high saturation magnetic induction of silicon steel with the low iron loss characteristics of the amorphous layer. This effectively reduces eddy current and hysteresis losses in the iron core, improving motor efficiency. The composite material also exhibits excellent mechanical properties, and the high bonding strength and stability make it ideal for motor cores.

Description

Technical Field

[0001] The present invention relates to the technical field of motor magnetic circuit components, and in particular to a silicon steel-amorphous composite material for a motor core, and preparation and application thereof. Background Art

[0002] Soft magnetic materials are magnetic materials with low coercivity and high magnetic permeability. They respond quickly to changes in external magnetic fields and achieve high magnetic induction with low losses. However, they are also easily magnetized and demagnetized by external magnetic fields. They are key structural and functional materials in traction motors, primarily used to manufacture their stator and rotor core components. They enable faster magnetic flux transmission, a more compact electromagnetic structure, and reduced energy loss in the stator and rotor cores.

[0003] Currently, the soft magnetic materials that have been applied mainly include silicon steel, Permalloy, iron-aluminum alloys, soft ferrites, iron-based amorphous alloys, nanocrystalline soft magnetic alloys, and soft magnetic composite materials. Among them, the soft magnetic materials currently used in motors are mainly silicon steel, which is also commonly known as electrical steel. It refers to an iron-silicon alloy with a carbon content of less than 0.02% and a silicon content of 1.5-4.5%. The addition of silicon forms an iron-silicon solid solution in the alloy, which increases the resistivity, reduces eddy current loss, and also reduces hysteresis loss, and increases the magnetic permeability under weak and medium magnetic field conditions. Non-oriented silicon steel sheets have high saturation magnetic density and high mechanical strength, and are widely used in various types of motor cores, including motor stators and rotor components.

[0004] Amorphous alloy is a new type of soft magnetic alloy material. It has no grain boundaries and dislocations, and no obstacles to hinder domain wall movement. Compared with electrical steel, it has the advantages of high magnetic permeability, low coercive force, high resistivity, thin thickness, corrosion resistance and excellent mechanical properties. This makes it possible to make it into motor cores. When working at high frequencies, the eddy current loss and hysteresis loss are very low, so the energy loss is very low, only 10% of that of silicon steel sheets or even less, which greatly improves the efficiency of the motor and has broad application prospects. Due to the advantages of amorphous alloys in reducing iron loss, it provides a new material system for manufacturers of high-efficiency motors.

[0005] For soft magnetic materials, it is necessary to have a soft magnetic core material that takes into account both high saturation magnetic induction intensity and low iron loss. The improvement of saturation magnetic induction intensity and saturation magnetic flux density is conducive to increasing current density, reducing material weight, and achieving high torque performance requirements; low iron loss is conducive to improving motor efficiency and improving the design requirements of the motor's heat dissipation and cooling system. Currently, there is a technical solution that makes silicon steel and amorphous into composite materials in order to achieve complementary advantages between the two, but the effect is not significant. For example, patent application CN106602754A uses non-oriented silicon steel strips and amorphous soft magnetic thin strips for composite. Although it can make the manufactured amorphous-silicon steel composite stator core have the characteristics of low loss and high saturation magnetic induction intensity to a certain extent, because it is essentially a mechanical stacking of silicon steel and amorphous materials, and the thickness of the amorphous material is 0.02 to 0.05 mm, this is not conducive to the application of this material in motors. As the content of the amorphous layer increases, the mechanical strength of the composite decreases and cannot meet the requirements of the motor. The strength requirements of the iron core, and the silicon steel-amorphous composite material with a mechanical hybrid structure design will limit the application field of the motor, especially in the medium and low frequency motors, the amorphous layer cannot play the advantage of low iron loss; for example, the laminate of the magnetic substrate composed of a polymer compound layer and a magnetic metal sheet prepared in patent application CN1856847A is also a mechanical lamination processing method, and the middle layer is resin, which is pressed and composited by hot pressing. This makes it possible that when this method is implemented, the amorphous material will produce crystallization during the hot pressing process, resulting in magnetic performance degradation or even failure, and the performance advantages of the amorphous material cannot be brought into play.

[0006] Therefore, it is of great significance to study a silicon steel-amorphous composite material for motor core that can maximize the advantages of silicon steel and amorphous materials and have high mechanical strength, low iron loss and high saturation magnetic induction intensity under low, medium and high frequency conditions. Summary of the Invention

[0007] The present invention provides a silicon steel-amorphous composite material for motor cores and its preparation and application, which are used to solve the defect of poor performance of soft magnetic materials for motor cores in the prior art. Silicon steel and amorphous materials are combined through a magnetron sputtering process to realize the preparation of the silicon steel-amorphous composite material for motor cores and give full play to the complementary effect of the advantages of the two. The prepared silicon steel-amorphous composite material has both the high saturation magnetic induction intensity of silicon steel and the low iron loss characteristics of the amorphous layer, which can effectively reduce the eddy current loss and hysteresis loss of the core and improve the efficiency of the motor. The composite material has good mechanical properties and high bonding strength and stability, and is very suitable for motor cores.

[0008] Specifically, the present invention provides a method for preparing a silicon steel-amorphous composite material for a motor core, comprising: using Fe 70～90 Si 5～12 B 8～15A series of target materials are magnetron sputtered on the surface of a pretreated silicon steel sheet to obtain a silicon steel amorphous composite material with an amorphous layer of 100 to 1000 nm thick on the surface.

[0009] When silicon steel and amorphous material are combined, the processing methods that can be selected are various. The present invention has found through in-depth research on silicon steel-amorphous composite materials that the performance of silicon steel-amorphous composite materials is greatly affected by the processing method and the structure formed by it. For example, the processing method of mechanical pressing commonly used at present has put forward higher requirements for the thickness, mechanical strength and other properties of amorphous materials, or inappropriate post-processing methods can easily cause the structure or performance of amorphous materials to decline. In the research of the present invention, it is noted that if amorphous materials are directly formed on silicon steel materials, there are also huge technical difficulties. For example, the magnetron sputtering process used in the present invention has a very critical thickness when forming an amorphous layer. Specifically, the thickness of the amorphous layer has a huge impact on the eddy current loss and hysteresis loss of the iron core. Although the thicker the amorphous layer, the lower the eddy current loss and hysteresis loss, the iron loss is also reduced, and the motor efficiency is improved. However, the thicker the amorphous layer, the easier it is to produce crystallization during processing and use, resulting in magnetic performance decline or even failure, which in turn leads to an increase in motor iron loss and a decrease in motor efficiency. Therefore, it is extremely important to reasonably control the thickness of the amorphous layer for the performance control of silicon steel-amorphous composite materials. 70～90 Si 5～12 B 8～15 For a series of target materials, when the thickness is controlled to be 100-1000nm, the role of the amorphous layer in improving the eddy current loss and hysteresis loss of the silicon steel sheet can be maximized and the stability of the amorphous layer structure and performance can be achieved, thereby reducing iron loss and improving motor efficiency. The thickness is further preferably 500nm-800nm.

[0010] According to the method for preparing the silicon steel-amorphous composite material for motor core provided by the present invention, the sputtering gas pressure used when obtaining the amorphous layer by magnetron sputtering is 0.1Pa-2Pa.

[0011] The present invention compared the sputtering pressure during magnetron sputtering to form an amorphous layer. It was found that sputtering pressure primarily affects the microstructure of the amorphous film. Lower sputtering pressures slowed film growth and reduced production efficiency. Higher sputtering pressures made it difficult to control film thickness uniformity, affecting the stability of the amorphous magnetic properties. The best overall effect was achieved when the amorphous layer was formed using a sputtering pressure of 0.1 Pa to 2 Pa.

[0012] According to the preparation method of the silicon steel-amorphous composite material for the motor core provided by the present invention, before depositing the amorphous layer, a SiO2 target is used to perform magnetron sputtering on the surface of the silicon steel sheet to obtain a first insulating layer; and / or, after depositing the amorphous layer, a SiO2 target is used to perform magnetron sputtering on the surface of the silicon steel amorphous composite material to obtain a second insulating layer.

[0013] The present invention further provides a first insulating layer between the silicon steel sheet and the amorphous layer. The insulating layer mainly functions to isolate the silicon steel sheet and the amorphous layer, thereby reducing eddy current loss.

[0014] Based on the consideration of the influence of crystallization of the amorphous layer caused by external factors during subsequent transportation and processing, the present invention further provides a second insulating layer on the amorphous layer. Through experiments, it is found that the second insulating layer can effectively protect the amorphous layer and stabilize its structure and performance.

[0015] According to the preparation method of the silicon steel-amorphous composite material for the motor core provided by the present invention, the sputtering pressure used when the first insulating layer is obtained by magnetron sputtering is 0.1Pa~2Pa; and / or the sputtering pressure used when the second insulating layer is obtained by magnetron sputtering is 0.1Pa~2Pa.

[0016] During the formation of the insulating layer, the sputtering pressure primarily affects the surface roughness and point defects of the insulating layer. Point defects primarily refer to locally grown aggregated particles on the surface. These particles can easily cause tip discharges, disrupting the structure and thickness uniformity of the insulating layer. When the sputtering pressure is controlled within the range of 0.1 Pa to 2 Pa, the insulating layer structure is optimal.

[0017] In the process of forming the first insulating layer and the second insulating layer in the present invention, the background vacuum reaches 5.5×10 -3 Pa, the deposition temperature is lower than 200 ° C. The lower deposition temperature is used mainly because it has less impact on the insulating layer. High deposition temperature can easily damage the insulating layer, and high deposition temperature can also easily cause crystallization of the amorphous layer, resulting in performance failure of the amorphous layer.

[0018] According to the method for preparing the silicon steel-amorphous composite material for motor core provided by the present invention, the thickness of the first insulating layer is 10 to 200 nm; and / or the thickness of the second insulating layer is 10 to 200 nm.

[0019] Research has found that the thickness of the insulation layer affects the magnetic flux of the iron core. The thinner the insulation layer, the smaller the cross-sectional area, the lower the losses, and the higher the motor efficiency. However, the thinner the insulation layer, the lower the resistance and thermal conductivity between the silicon steel sheets. Therefore, the thickness of the insulation layer needs to be controlled within a reasonable range, preferably between 50 and 150 nm.

[0020] The deposition processes for the first and second insulating layers described above can be the same or different. When preparing the silicon steel-amorphous composite material for motor cores according to the present invention, the insulating layer and the amorphous layer can be prepared in the same chamber. This prevents the introduction of impurities and mechanical stress during the transfer process, ensuring the integrity and uniformity of the amorphous layer on the silicon steel surface.

[0021] Furthermore, the insulating layer designed in the present invention is made of SiO2, which is easy to process, has stable performance, and produces a layered structure with excellent mechanical properties. Furthermore, when the silicon steel, amorphous film, and insulating layer all contain Si, the magnetic permeability can be improved. This material selection, along with the thickness and structure design, ensures that the amorphous film meets the performance requirements of high saturation induction and low iron loss in applications such as high-frequency, medium-frequency, and low-frequency motor cores.

[0022] According to the method for preparing a silicon steel-amorphous composite material for a motor core provided by the present invention, the thickness of the silicon steel sheet is 0.2 to 1 mm. The thickness of the silicon steel sheet can affect the loss and efficiency of the motor core. As the thickness of the silicon steel sheet decreases, the loss decreases accordingly, but the cost also increases. To meet actual production needs, silicon steel sheets with a thickness of 0.2 to 0.6 mm are selected.

[0023] According to the method for preparing the silicon steel-amorphous composite material for motor core provided by the present invention, the silicon steel sheet is a silicon steel sheet that has been surface polished and ultrasonically cleaned.

[0024] According to the preparation method of silicon steel-amorphous composite material for motor core provided by the present invention, Fe 70～90 Si 5～12 B 8～15 The purity of the target material series is ≥99.99%. The background vacuum used in the magnetron sputtering to obtain the amorphous layer is 5.5×10 -3 Pa or above, and the deposition temperature is lower than 200° C. Under this process condition, magnetron sputtering is performed, and the amorphous layer structure formed is more stable and controllable.

[0025] The present invention also provides a silicon steel-amorphous composite material for a motor iron core, which is prepared by the method for preparing the silicon steel-amorphous composite material for a motor iron core.

[0026] The present invention also provides application of the silicon steel-amorphous composite material for motor core as described above in the motor core.

[0027] When carrying out specific applications, mechanical processing equipment such as wire cutting, laser cutting and punching can be used to process finished products with required dimensions and surface quality according to the dimensions required by the application.

[0028] The present invention provides a method for preparing a silicon steel-amorphous composite material for a motor core, by using Fe 70～ 90 Si 5～12 B 8～15 A series of target materials are magnetron sputtered on the surface of pretreated silicon steel sheets to obtain silicon steel amorphous composite materials with an amorphous layer 100 to 1000 nm thick on the surface, and then a silicon steel-amorphous composite material with a multi-layer structure is prepared. This material can replace traditional silicon steel materials and be used in motors to reduce iron loss and improve efficiency.

[0029] The present invention provides a method for preparing a silicon steel-amorphous composite material for motor cores. By switching the type of target material in the same coating chamber, effective deposition of different materials is achieved. The thin film layer has low surface roughness, good thickness uniformity, and high interface bonding strength.

[0030] The present invention provides a method for preparing a silicon steel-amorphous composite material for a motor core. The preparation process is simple and has good repeatability, which is conducive to industrial large-scale production.

[0031] The present invention provides a silicon steel-amorphous composite material for motor cores, which is prepared by a method for preparing a silicon steel-amorphous composite material for motor cores. Through multiple verification tests, its performance test results show that the material has both the high saturation magnetic induction characteristics of silicon steel and the low iron loss performance of amorphous. The test results of the prepared iron core show that the hysteresis loss and eddy current loss are effectively reduced. During the application of the motor, the iron loss is reduced and the efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 It is a structural schematic diagram of the equipment used for the silicon steel-amorphous composite material provided by the present invention.

[0034] Reference numerals:

[0035] 1: Deposition base; 2: Silicon steel sheet; 3: Plasma; 4: FeSiB target; 5: SiO2 target; 6: Target rotation control mechanism. DETAILED DESCRIPTION

[0036] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0037] If no specific techniques or conditions are specified in the examples, the experiments were carried out according to the techniques or conditions described in the literature in the field or according to the product instructions. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased through regular channels.

[0038] Fe in the present invention 70～90 Si 5～12 B 8～15 The target series includes: Fe 75 Si 10 B 15 Target, Fe 72 Si 13 B 15 Target and Fe 72 Si 10 B 18 The target material is referred to as FeSiB target material in the following examples.

[0039] The present invention adopts the equipment for preparing silicon steel-amorphous composite material, such as Figure 1 As shown, it includes a deposition base 1, a silicon steel sheet 2, a plasma 3, a FeSiB target 4, a SiO2 target 5 and a target rotation control mechanism 6; wherein, the target rotation control mechanism 6 is used to regulate the opening and movement of the target, and can control the opening and closing of the SiO2 target and the FeSiB target, as well as the sputtering area. When preparing the silicon steel-amorphous composite material, first, a first insulating layer is deposited on the surface of the silicon steel 2 using a SiO2 target 5. At this time, the main component of the plasma 3 is SiO2 ions, resulting in a silicon steel / SiO2 composite. Then, the target rotating mechanism 6 is used to adjust the target to the FeSiB target 4, and an amorphous layer is deposited on the surface of the insulating layer. At this time, the main component of the plasma 3 is FeSiB ions, resulting in a silicon steel / SiO2 / FeSiB composite. Finally, the target rotating mechanism 6 is used to adjust the target to the SiO2 target 5, and a second insulating layer is deposited on the surface of the amorphous layer. At this time, the main component of the plasma 3 is SiO2 ions, resulting in a silicon steel / SiO2 / FeSiB / SiO2 composite with a multilayer structure, i.e., a silicon steel-amorphous composite material.

[0040] Examples 1 to 11

[0041] Use Figure 1The method for preparing silicon steel-amorphous composite materials using the device for preparing silicon steel-amorphous composite materials shown in the figure comprises the following steps:

[0042] (1) Silicon steel sheet cleaning: Select silicon steel sheets with a thickness of 0.3 mm, perform surface polishing, ultrasonic cleaning, and drying on the silicon steel sheets to remove the oxide layer and oil stains to ensure the cleanliness of the silicon steel surface, and place them in the coating chamber;

[0043] (2) Pump the background vacuum to 3.0×10 -3 Pa, set deposition temperature (the temperature remains constant during the deposition process);

[0044] (3) Depositing the first insulating layer: Opening the SiO2 target, depositing the SiO2 insulating layer on the surface of the silicon steel sheet in step (1). The target material and deposition process used are shown in Table 1;

[0045] (4) Deposition of amorphous layer: Turn off the SiO2 target, turn on the FeSiB target, and deposit an amorphous layer on the surface of the silicon steel / SiO2 composite material obtained in step (2). The target materials, deposition process and thickness of the amorphous layer are shown in Table 1.

[0046] (5) Deposition of the second insulating layer: The FeSiB target is closed, and the SiO2 target is opened. The SiO2 insulating layer is deposited on the surface of the silicon steel / SiO2 / FeSiB composite material obtained in step (3). The target material, deposition process and thickness of the second insulating layer are shown in Table 1. After the deposition is completed, the furnace is cooled and the silicon steel-amorphous composite material for the motor core is obtained.

[0047] Example 12

[0048] A method for preparing a composite material, wherein the steps are substantially the same as those in Example 2, except that the thickness of the silicon steel sheet in step (1) is replaced with a silicon steel sheet of 0.1 mm.

[0049] Comparative Example 1

[0050] A method for preparing a composite material, wherein the steps are substantially the same as those in Example 1, except that step (4) is not included.

[0051] Table 1

[0052]

[0053]

[0054] The composite materials prepared in Examples 1-14 and Comparative Examples 1-2 were subjected to wire cutting to produce annular specimens with an outer diameter of 80 mm and an inner diameter of 62 mm. These specimens were then used in motors for comparative testing. The testing methods were in accordance with GB755-2008, GB1032-2012, and GB18613-2016. The test results are shown in Table 2.

[0055] Table 2

[0056]

[0057]

[0058] From the comparison results of Example 1 and Comparative Example 1, it was found that after the amorphous layer was deposited on the surface of the silicon steel sheet, the low-frequency iron loss of the iron core prepared by the composite material was reduced from 2.4W / kg to 1.6W / kg, the motor efficiency was also improved from 93.5% to 97.2%, and the high-frequency iron loss was also reduced from 32.3W / kg to 20.3W / kg.

[0059] A comparison of Examples 1, 2, 3, 5, and 6 shows that the thickness of the amorphous layer varies from 100 nm to 800 nm. During application, when the thickness of the amorphous layer exceeds 700 nm, the amorphous layer undergoes serious crystallization, deteriorates magnetic properties, and suppresses iron loss, thereby reducing motor efficiency.

[0060] Comparison between Example 3 and Example 4 shows that the effect of the insulating layer increasing from 50 nm to 120 nm on the performance of the silicon steel-amorphous composite material does not change much.

[0061] Comparative results from Examples 2, 7, 8, and 9 show that increasing the sputtering pressure improves the density of the sputtered amorphous layer, enhances the composite effect of the silicon steel insulating layer and the amorphous layer, and improves the strength and mechanical properties of the silicon steel-amorphous composite material. However, the iron loss of the composite material increases, primarily due to changes in the sputtering pressure, which affects the surface quality of the amorphous layer. Excessive sputtering pressure can produce point defects on the surface, affecting the magnetic properties of the composite material.

[0062] Comparing the results of Example 2 and Example 12, it was found that the silicon steel material (0.3mm) with an amorphous layer added had lower iron loss and higher efficiency than the ultra-thin silicon steel sheet (0.1mm thickness). The price of 0.1mm silicon steel sheet was much higher than that of 0.3mm silicon steel sheet. This shows that amorphous layer silicon steel sheet can significantly improve efficiency and reduce cost for the preparation of high-efficiency motors.

[0063] Comparison of the results of Examples 2, 10, and 11 reveals that the properties of the silicon steel-amorphous composite material obtained by depositing the amorphous layer with FeSiB targets of different atomic ratios do not change much.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for preparing a silicon steel-amorphous composite material for motor core, characterized in that: include: Fe 70~ 90 Si 5~12 B 8~15 A series of target materials were magnetron sputtered on the surface of pretreated silicon steel sheets to obtain silicon steel amorphous composite materials with a 150nm thick amorphous layer on the surface; The thickness of the silicon steel sheet is 0.2-1 mm; The sputtering gas pressure used when the amorphous layer is obtained by magnetron sputtering is 1.2 Pa; Before depositing the amorphous layer, magnetron sputtering is performed on the surface of the silicon steel sheet using a SiO2 target to obtain a first insulating layer; after depositing the amorphous layer, magnetron sputtering is performed on the surface of the silicon-steel amorphous composite material using a SiO2 target to obtain a second insulating layer; The thickness of the first insulating layer is 10-200 nm; The background vacuum used in the magnetron sputtering to obtain the amorphous layer is 5.5×10 -3 Pa or above, the deposition temperature is lower than 200℃; During the formation of the first and second insulating layers, the background vacuum reached 5.5×10 -3 Pa and the deposition temperature is lower than 200℃.

2. The method for preparing the silicon steel-amorphous composite material for motor core according to claim 1, characterized in that: The sputtering pressure used when the first insulating layer is obtained by magnetron sputtering is 0.1 Pa~2 Pa; and / or the sputtering pressure used when the second insulating layer is obtained by magnetron sputtering is 0.1 Pa~2 Pa.

3. The method for preparing the silicon steel-amorphous composite material for motor core according to claim 2, characterized in that: The thickness of the second insulating layer is 10-200 nm.

4. The method for preparing the silicon steel-amorphous composite material for motor core according to any one of claims 1 to 3, characterized in that: The silicon steel sheet is a silicon steel sheet that has been surface polished and ultrasonically cleaned.

5. The method for preparing the silicon steel-amorphous composite material for motor core according to claim 1, characterized in that: Fe 70~90 Si 5~12 B 8~15 The purity of the series targets is ≥99.99%.

6. A silicon steel-amorphous composite material for a motor core produced by the method for producing a silicon steel-amorphous composite material for a motor core according to any one of claims 1 to 5.

7. Use of the silicon steel-amorphous composite material for motor core according to claim 6 in motor core.

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