A method for manufacturing low-loss iron-based nanocrystalline strip

Abstract

The application relates to a low-loss iron-based nanocrystalline strip manufacturing method and belongs to the technical field of nanocrystalline soft magnetic alloy. The method comprises the following steps: S1, the nanocrystalline strip (1) is coated with an insulating glue solution on the nanocrystalline strip (1); S2, the insulating glue solution on the smooth surface of the nanocrystalline strip (1) is brushed off; S3, the nanocrystalline strip (1) is extruded to flatten the insulating layer (102) on the rough surface of the nanocrystalline strip (1); and S4, the nanocrystalline strip (1) is baked and solidified. The surface of the low-loss iron-based nanocrystalline strip is coated with an insulating layer, the interlayer insulation of the nanocrystalline magnetic core is improved, and the eddy current loss of the magnetic core can be effectively reduced.

Description

TECHNICAL FIELD

[0001] The application relates to a low-loss iron-based nanocrystalline strip manufacturing method. BACKGROUND

[0002] With the development of information communication and power electronic technology, electronic components are required to be miniaturized, and the electronic components are required to have low loss to reduce the heating loss of the components. The iron-based nanocrystalline alloy strip has excellent soft magnetic properties, high resistivity and low high-frequency loss, and a nanocrystalline magnetic core manufactured by using the nanocrystalline alloy strip is widely applied to the power electronic industry. The nanocrystalline magnetic core is manufactured by winding nanocrystalline strips with a certain width and thickness into a magnetic core with a required inner and outer diameter (mostly in the original shape), and then performing a corresponding heat treatment process. When the magnetic core is wound into a transformer or an inductive device, an induced electromotive force is generated in the magnetic core under the action of a certain applied excitation current, thereby generating a current heating loss, i.e. the eddy current loss of the magnetic core. Meanwhile, the higher the frequency, the higher the induced electromotive force, and the internal resistance of the magnetic core is unchanged, so the eddy current loss of the magnetic core is larger. At present, the method for reducing the eddy current loss of the nanocrystalline magnetic core is to reduce the thickness of the sprayed strip, increase the number of winding layers of the magnetic core, and increase the internal resistance of the magnetic core to reduce the eddy current loss. At present, the main spraying thickness of the iron-based nanocrystalline strip is 18-24 um, and the thinner the thickness of the strip, the lower the eddy current loss. However, the iron-based nanocrystalline strip with a thickness of less than 18 um cannot be mass-produced at present. Generally, the thinner the nanocrystalline strip, the poorer the density. The stacking factor (filling factor) of the nanocrystalline strip with a thickness of less than 18 um is generally not higher than 0.8, so that the effective cross-sectional area of the magnetic core after being wound is low, and the performance of the magnetic core is poor. SUMMARY

[0003] The technical problem to be solved by the application is to overcome the shortcomings of the prior art and provide a low-loss iron-based nanocrystalline strip manufacturing method capable of obtaining a magnetic core wound by nanocrystalline strips and effectively reducing the eddy current loss.

[0004] The technical scheme adopted by the application to solve the technical problem is that the low-loss iron-based nanocrystalline strip manufacturing method comprises the following steps.

[0005] S1. The nanocrystalline strip is coated with an inorganic insulating glue solution.

[0006] S2. The inorganic insulating glue solution on the smooth surface of the nanocrystalline strip is brushed off.

[0007] S3. The nanocrystalline strip is extruded to flatten the insulating layer of the rough surface of the nanocrystalline strip.

[0008] S4. The nanocrystalline strip is baked and solidified.

[0009] Preferably, the thickness of the insulation layer is less than 5um.

[0010] Preferably, the inorganic insulation glue solution is aluminum dihydrogen phosphate glue solution and inorganic insulation powder, and the weight content of the inorganic insulation powder is 5-30%, and the inorganic insulation powder is one of alumina, magnesia, silica, aluminum nitride, silicon nitride, and sialon ceramic or a mixture of at least two thereof in any ratio.

[0011] Preferably, the inorganic insulation glue solution of the nanocrystalline strip is brushed off by a brush belt roller.

[0012] Preferably, the insulation layer of the nanocrystalline strip is flattened by a drag belt roller and a press belt roller.

[0013] Preferably, the thickness of the insulation layer is adjusted by adjusting the spacing of the drag belt roller and the press belt roller.

[0014] Preferably, the nanocrystalline strip is baked and cured by an oven.

[0015] Preferably, the baking temperature of the nanocrystalline strip is 150-300℃.

[0016] The conventional magnetic material insulation layer (such as silicon steel sheet) generally uses organic adhesive spraying insulation because subsequent heat treatment is not required. The conventional organic adhesive has a temperature resistance generally lower than 300℃, and the nanocrystalline strip needs heat treatment at 500-600℃ after being wound into a magnetic core. The aluminum dihydrogen phosphate is a high-temperature inorganic insulation adhesive with heat curing, and has low-temperature (90-110℃) adhesion and high-temperature (above 350℃) heat curing. The nanocrystalline strip with a soft insulation layer is obtained by a wetting, rolling and low-temperature baking process, and the magnetic core is wound, and the insulation layer is hardened during heat treatment of the magnetic core.

[0017] Compared with the prior art, the application has the beneficial effects that:

[0018] The surface coating insulation layer of the low-loss iron-based nanocrystalline strip manufacturing method improves the interlayer insulation of the nanocrystalline magnetic core, and can effectively reduce the eddy current loss of the magnetic core. BRIEF DESCRIPTION OF DRAWINGS

[0019] Fig. 1 It is a cross-sectional view of the low-loss iron-based nanocrystalline strip.

[0020] Fig. 2 It is a process schematic diagram of coating the insulation layer of the nanocrystalline strip.

[0021] In the figure: 1, nanocrystalline strip; 101, base layer; 102, insulation layer; 2, unwinding reel; 3, guide roller; 4, insulation liquid box; 5, brush belt roller; 6, input drag belt roller; 7, press belt roller; 8, oven; 9, support roller; 10, output drag belt roller; 11, winding reel. DETAILED DESCRIPTION

[0022] The application will be further described below in connection with specific embodiments, however, it should be understood that the detailed description given here with reference to the drawings is intended to explain the application better, the structure of the application certainly exceeds the limited embodiments, and for some equivalent alternatives or common means, the detailed description will not be given here, but still belongs to the protection scope of the application.

[0023] Figs. 1-2 is the best embodiment of the application, and the following will be described in connection with the drawings Figs. 1-2 The application will be further described below in connection with specific embodiments, however, it should be understood that the detailed description given here with reference to the drawings is intended to explain the application better, the structure of the application certainly exceeds the limited embodiments, and for some equivalent alternatives or common means, the detailed description will not be given here, but still belongs to the protection scope of the application.

[0024] As shown in Fig. 1 : The nanocrystalline strip 1 includes a base layer 101 and an insulating layer 102, the bottom of the base layer 101 is a smooth surface, and the top is a rough surface, the insulating layer 102 is arranged on the rough surface of the base layer 101, and the top of the insulating layer 102 is smooth.

[0025] As shown in Fig. 2 : The application also provides a process equipment for dipping an insulating layer for a nanocrystalline strip, which includes a strip unwinding reel 2, an insulating liquid box 4, a strip brushing roller 5, an input strip dragging roller 6, a strip pressing roller 7, an oven 8, an output strip dragging roller 10 and a strip winding reel 11.

[0026] The strip unwinding reel 2 and the strip winding reel 11 are both horizontally arranged, and the strip unwinding reel 2 and the strip winding reel 11 are arranged at intervals. The insulating liquid box 4 and the oven 8 are sequentially arranged between the strip unwinding reel 2 and the strip winding reel 11. The insulating liquid box 4 is rotatably provided with a guide roller 3, the guide roller 3 is located below the liquid surface of the insulating liquid box 4, and the guide roller 3 is parallel to the strip unwinding reel 2.

[0027] The strip brushing roller 5 is arranged directly above the insulating liquid box 4, and the strip brushing roller 5 is parallel to the guide roller 3.

[0028] The input side of the oven 8 is provided with the input strip dragging roller 6 and the strip pressing roller 7, the strip pressing roller 7 is arranged directly above the input strip dragging roller 6, and the strip unwinding reel 6 and the strip pressing roller 7 are both parallel to the strip unwinding reel 2. The output side of the oven 8 is provided with the output strip dragging roller 10, and the output strip dragging roller 10 is parallel to the strip winding reel 11. The oven 8 is rotatably provided with a supporting roller 9, and the supporting roller 9 is parallel to the strip unwinding reel 2.

[0029] The nanocrystalline strip 1 wound on the strip unwinding reel 2 sequentially passes the underside of the guide roller 3, the upside of the strip brushing roller 5, enters the oven 8 between the strip pressing roller 7 and the input strip dragging roller 6, and is wound on the strip winding reel 11 after sequentially passing the supporting roller 9 and the output strip dragging roller 10. The strip unwinding reel 2 and the strip winding reel 11 cooperate to maintain a certain tension of the nanocrystalline strip 1.

[0030] A low-loss iron-based nanocrystalline strip manufacturing method, comprising the following steps:

[0031] S1 passes the nanocrystalline strip 1 through an inorganic insulating glue solution to coat the inorganic insulating glue solution on the nanocrystalline strip 1.

[0032] After the nanocrystalline strip 1 is guided by the guide roller 3, the inorganic insulating glue solution is coated on the nanocrystalline strip 1. In this embodiment, the inorganic insulating glue solution is an aluminum dihydrogen phosphate glue solution and inorganic insulating powder, and the weight content of the inorganic insulating powder is 5-30%, and the inorganic insulating powder is one of alumina, magnesia, silica, aluminum nitride, silicon nitride, and a mixture of at least two of them in any ratio, wherein the type and content of the inorganic insulating powder, such as alumina, magnesia, silica, aluminum nitride, silicon nitride, and sialon ceramic, are adjusted according to the working conditions.

[0033] S2 brushes off the inorganic insulating glue solution on the smooth surface of the nanocrystalline strip 1.

[0034] The inorganic insulating glue solution coated on the smooth surface of the nanocrystalline strip 1 is brushed off by the brush wheel 5, and only the inorganic insulating glue solution on the rough surface is left to reduce the thickness of the insulating layer 102 of the nanocrystalline strip 1 and prevent the effective cross-section of the wound nanocrystalline magnetic core from being excessively reduced due to the excessive thickness of the coated insulating layer 102. The inorganic insulating glue solution coated on the rough surface can ensure the adhesion of the insulating layer 102 and prevent the insulating layer 102 from falling off.

[0035] S3 extrudes the nanocrystalline strip 1 to flatten the insulating layer 102 on the rough surface of the nanocrystalline strip 1.

[0036] The inorganic insulating glue solution coated on the rough surface is extruded and flattened by the extrusion action of the input drag roller 6 and the pressure roller 7, and the distance between the input drag roller 6 and the pressure roller 7 can be adjusted according to the thickness of the nanocrystalline strip 1 to ensure that the coating thickness of the insulating glue is less than 5um. The relative gap between the pressure roller 7 and the input drag roller 6 is adjusted to adjust the bonding thickness of the insulating layer 102.

[0037] S4 performs baking and curing on the nanocrystalline strip 1.

[0038] The coated and flattened nanocrystalline strip 1 is baked and cured in the oven 8, and the oven temperature is 150-300℃ to prevent overheating and crystallization failure of the nanocrystalline strip 1. The oven 8 is provided with a support roller 9 inside to prevent sagging during the movement of the strip.

[0039] The unwinding reel 2 and the winding reel 11 should maintain a certain tension and keep the linear speed of unwinding and winding consistent.

[0040] The length of the oven 8 should match the traveling speed of the nanocrystalline strip 1, aiming to control the baking time and ensure the complete bonding and curing of the aluminum dihydrogen phosphate insulating adhesive with the nanocrystalline strip 1. In order to improve the coating efficiency of the insulating layer 102, the length of the oven 8 can be appropriately extended, and the unwinding and winding speeds can be increased. In order to prevent the nanocrystalline strip 1 from sagging due to the excessive length of the oven 8, a plurality of synchronous supporting rollers 9 can be arranged inside the oven 8.

[0041] At present, the nanocrystalline strip is prepared by using molten steel liquid through rapid cooling and strip casting method. The lower surface (the roller surface) of the obtained nanocrystalline strip 1 is relatively smooth, and the upper surface (the back roller surface) is relatively rough, as shown in Fig. 1 There is an error in the width direction of the nanocrystalline strip 1. Generally, the transverse error of the qualified nanocrystalline strip 1 is required to be less than 5 um.

[0042] By utilizing the special structure of the surface of the nanocrystalline strip 1, the aluminum dihydrogen phosphate insulating paste is coated on the rough surface of the nanocrystalline strip 1 through the processes of insulating glue immersion, scraping, even paste pressing and baking. The magnetic core made of the nanocrystalline strip 1 with the coated insulating layer 102 is in an insulating state between the strip layers, which can reduce the eddy current loss,

[0043] The above description is only the preferred embodiment of the present application, and is not intended to limit the other forms of the present application. Any skilled person in the art can modify or change the above-mentioned technical content into equivalent embodiments with equivalent changes. However, any simple modification, equivalent change and modification made on the basis of the technical essence of the present application to the above-mentioned embodiments, which does not deviate from the technical solution content of the present application, still belongs to the protection scope of the technical solution of the present application.

Claims

1. A method of producing low loss iron-based nanocrystalline ribbon characterized by: It comprises the following steps: S1. Passing the nanocrystalline strip (1) through an inorganic insulating glue solution to coat the inorganic insulating glue solution on the nanocrystalline strip (1); S2. Brushing off the inorganic insulating glue solution on the smooth surface of the nanocrystalline strip (1); S3. Extruding the nanocrystalline strip (1) to flatten the insulating layer (102) on the rough surface of the nanocrystalline strip (1); S4. Baking and curing the nanocrystalline strip (1); The nanocrystalline strip (1) wound on the releasing reel (2) passes the lower side of the guide roller (3), the upper side of the brush roller (5), and then enters the oven (8) between the pressing roller (7) and the input trailing roller (6), and is wound on the take-up reel (11) after passing through the support roller (9) and the output trailing roller (10) in sequence; The inorganic insulating glue solution on the smooth surface of the nanocrystalline strip (1) is brushed off by the brush roller (5), and only the inorganic insulating glue solution on the rough surface is reserved; The inorganic insulating glue solution on the rough surface is extruded and flattened by the extrusion of the input trailing roller (6) and the pressing roller (7), the relative gap between the pressing roller (7) and the input trailing roller (6) is adjusted, and the bonding thickness of the insulating layer (102) is adjusted; The inorganic insulating glue solution is an aluminum dihydrogen phosphate glue solution and an inorganic insulating powder, and the weight content of the inorganic insulating powder is 5-30%, and the inorganic insulating powder is one of alumina, magnesia, silica, aluminum nitride, silicon nitride, and a mixture of at least two of them in any proportion.

2. The method of claim 1, wherein the low loss Fe-based nanocrystalline ribbon is produced by: The thickness of the insulating layer (102) is less than 5μm.

3. The method of claim 1, wherein the low loss Fe-based nanocrystalline ribbon is produced by: The nanocrystalline strip (1) is baked and cured by the oven (8).

4. The method of claim 1 or 3, wherein the low loss Fe-based nanocrystalline ribbon is produced by: The baking temperature of the nanocrystalline strip (1) is 150-300℃.

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