Iron-silicon compressed powder core, method for preparing the same, and inductor

Abstract

This specification discloses an iron-silicon compressed powder core, a method for preparing the same, and an inductor. 【Solution means】The preparation method includes: step (1) of mixing an iron-silicon alloy magnetic powder and a surface treatment agent to obtain a surface-treated magnetic powder; step (2) of mixing an inactivator, a solvent, and the surface-treated magnetic powder described in step (1) to obtain an inactivated magnetic powder; step (3) of performing an organic insulation binding on the inactivated magnetic powder described in step (2) to obtain a bound magnetic powder; step (4) of mixing a release agent and the bound magnetic powder described in step (3) to obtain a mixed magnetic powder material; and step (5) of performing press molding and annealing treatment on the mixed magnetic powder material described in step (4) to obtain the iron-silicon compressed powder core. The iron-silicon compressed powder core obtained by the preparation method according to the present application improves the insulation effect, reduces the eddy current loss, and improves the problems that the loss of the compressed powder core increases after the temperature rises and the temperature rises too fast.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical fields of soft magnetic alloy materials and powder metallurgy. For example, they relate to a method for preparing an iron-silicon compressed powder core, and in particular, to an iron-silicon compressed powder core, a method for preparing the same, and an inductor.

Background Art

[0002] Alloy magnetic powders composed of two elements, iron and silicon, and compressed powder cores manufactured therefrom are widely applied in various aspects such as alternating current inductors, output inductors, photovoltaic power supply inverter inductors, and new energy charging stand boost inductors due to characteristics such as high DC superposition characteristics, no noise, and low cost. With the rapid charging needs and the development of power electronics technology, the power density has increased rapidly, and higher requirements are also put forward for magnetic inductor elements. In particular, due to the increase in load and the improvement of DC superposition, the iron-silicon core needs to withstand a larger current. The rapid temperature rise of the core caused by a large current further increases the loss of iron-silicon. Eventually, the core fails in such a cycle.

[0003] The main process of the metal soft compressed powder core is to mix metal powder and an insulating material to form a uniform and dense layer of insulating material on the powder surface. After drying the powder, lubricating powder is added, and then a product of the desired shape is formed in the mold of a press. Finally, the product is heat-treated under certain atmosphere and temperature conditions to remove defects and excess non-magnetic substances in the product and obtain a product with good comprehensive performance. As can be seen from the above manufacturing process, the main factors affecting core loss and temperature characteristics are the iron-silicon magnetic powder and the insulating material used. The loss and temperature rise of the iron-silicon alloy are its characteristics, and the only way to change the temperature rise characteristics is to start from the insulating material.

[0004] CN112530656A discloses a method for preparing a low-loss iron-silicon compressed powder core, which includes steps of alloy melting, crushing, screening, surface treatment, insulation coating, lubricant addition, press forming, heat treatment and surface coating treatment. However, in the screening process, powders are blended at a mass ratio of -325 mesh : -250 mesh : -120 mesh = 2:3:1, and the surface of the compressed powder core is subjected to coating treatment after the heat treatment is completed. The main component of the low-loss iron-silicon compressed powder core of this application is an iron-silicon binary alloy, and 0.22 - 0.25% of chromium element, 0.08 - 0.15% of vanadium, and 6.7 - 7.0% of silicon are added, with the balance being iron. The iron-silicon compressed powder core prepared in this application can reach a saturation magnetic flux density of 1.6 T or more, and the volume specific loss Pcv at 50 kHz and 500 Gs can be as low as 125 - 135 mW / cm 3 and can be low. The iron-silicon compressed powder core of this application has the advantages of high saturation magnetic flux density and low loss.

[0005] CN113299451A discloses an iron-silicon compressed powder core with an FeNi nanoparticle / epoxy resin composite coating, and its preparation method includes a powder mixing step, a modification step, an insulation coating step, a baking step, a press forming step and a vacuum annealing treatment step. This application is mainly composed of iron-silicon powder, and a layer of FeNi nanoparticle / epoxy resin coating layer is constructed on the surface. The obtained iron-silicon compressed powder core has advantages such as low magnetic loss, high permeability, high density of the product, and low cost compared with related products.

[0006] In the above technical solutions, the low loss of the compressed powder core has been improved in each case. However, in CN112530656A, there is still a deficiency that the molding pressure is high and the powder particle size grading is complex. The problem of the loss part after the temperature rise of the core is not sufficiently disclosed. In addition, for the iron-silicon alloy powder making, trace elements such as precious metals like chromium and vanadium are used, which increases the cost, and the technical problem of iron-silicon rusting cannot be solved, and the effect of reducing the raw material cost cannot be obtained either. CN113299451A uses a high-cost nano FeNi material, and the baking process requires characteristic processes such as a vacuum environment. Also, the role of the FeNi material in this application is not fully explained. The magnetic permeability of the samples in the examples has not been significantly improved, and the loss of the compressed powder core according to this application is higher than the industry standard, without obvious advantages, and the change rule of the loss with the temperature rise of the core is not explained either.

[0007] Therefore, how to improve the problem that the loss of the core increases with the temperature rise needs to be urgently solved in the technical fields of soft magnetic alloy materials and powder metallurgy.

Summary of the Invention

Problems to be Solved by the Invention

[0008] The following is an overview of the subject matter to be described in detail in this manuscript. This overview does not limit the scope of the claims.

[0009] In order to solve the above technical problems, the embodiments of the present application provide an iron-silicon compressed powder core, a preparation method thereof, and an inductor, which improve the heat dissipation performance of the compressed powder core by strengthening the passivation and insulation effects, and effectively solve the problems that the loss of the iron-silicon alloy-based compressed powder core is high and the temperature rises rapidly.

Means for Solving the Problems

[0010] In aspect 1, the embodiments of the present application are Step (1) of mixing an iron-silicon alloy magnetic powder and a surface treatment agent to obtain a surface-treated magnetic powder, Mixing an inactivator, a solvent, and the surface-treated magnetic powder described in step (1) to obtain an inactivated magnetic powder in step (2); Performing organic insulation binding on the inactivated magnetic powder described in step (2) to obtain a bound magnetic powder in step (3); Mixing a release agent and the bound magnetic powder described in step (3) to obtain a mixed magnetic powder material in step (4); Performing press molding and annealing treatment on the mixed magnetic powder material described in step (4) to obtain the iron-silicon compacted magnetic core in step (5), including: Providing a method for preparing an iron-silicon compacted magnetic core.

[0011] The preparation method according to the present application changes the tendency that the loss of the iron-silicon compacted magnetic core increases after the temperature rises by strengthening the inactivation and insulation effects, maintains the loss constant, and further reduces it slightly, overcoming the problem that the loss increases due to the temperature rise caused by the increase in superposition.

[0012] The iron-silicon alloy magnetic powder according to the present application is a normal iron-silicon alloy magnetic powder in this field and is not specifically limited.

[0013] Preferably, the particle size range of the iron-silicon alloy magnetic powder described in step (1) is 15 to 150 μm. For example, it may be 15 μm, 50 μm, 100 μm, 125 μm, or 150 μm, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0014] Preferably, among the iron-silicon alloy magnetic powder described in step (1), the mass of the particle size range of 75 to 150 μm accounts for 40 wt% or more of the total mass. For example, it may be 40 wt%, 45 wt%, 50 wt%, 55 wt%, or 65 wt%, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0015] Preferably, among the iron-silicon alloy magnetic powders described in step (1), the mass of the particle size range of 15 to 35 μm accounts for 30% or more of the total mass. For example, it may be 30 wt%, 40 wt%, 45 wt%, 50 wt% or 55 wt%, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0016] The particle size range of the iron-silicon alloy magnetic powder according to the present application increases the utilization rate of low-cost materials.

[0017] Preferably, the surface treatment agent described in step (1) contains an organic aluminum aerosol.

[0018] The organic aluminum aerosol according to the present application can effectively improve the surface state of the iron-silicon alloy magnetic powder and contribute to performing the inactivation treatment.

[0019] Preferably, the mass of the surface treatment agent described in step (1) is 0.5 to 1.5 wt% of the iron-silicon alloy magnetic powder. For example, it may be 0.5 wt%, 0.8 wt%, 1 wt%, 1.2 wt% or 1.5 wt%, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0020] Preferably, after the mixing described in step (1), it further includes baking.

[0021] Preferably, the temperature of the baking is 75 to 85 °C. For example, it may be 75 °C, 78 °C, 80 °C, 82 °C or 85 °C, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0022] Preferably, the inactivator described in step (2) contains a water-soluble inorganic material, and is preferably phosphoric acid and / or aluminum dihydrogen phosphate.

[0023] Preferably, the mass of the deactivator described in step (2) is 0.15 to 2.5 wt% of the iron-silicon alloy magnetic powder. For example, it may be 0.15 wt%, 0.5 wt%, 0.8 wt%, 1 wt%, 1.2 wt%, 1.5 wt%, 2 wt% or 2.5 wt%, but is not limited to the enumerated values, and other unenumerated values within the numerical range are equally applicable.

[0024] Preferably, the solvent described in step (2) contains deionized water.

[0025] Preferably, the mass of the solvent described in step (2) is 1.5 to 3 times that of the deactivator. For example, it may be 1.5 times, 1.8 times, 2 times, 2.5 times or 3 times, but is not limited to the enumerated values, and other unenumerated values within the numerical range are equally applicable.

[0026] Preferably, it further includes drying after the mixing described in step (2).

[0027] Preferably, before the organic insulation binding described in step (3), it further includes mixing a silane coupling agent with the deactivated magnetic powder described in step (2).

[0028] The silane coupling agent according to the present application is mixed with the deactivated magnetic powder before binding, increases the uniformity of the application of the binder to the surface of the magnetic powder, and contributes to enhancing the permeability of the binder.

[0029] The silane coupling agent includes any one or at least a combination of two or more of vinyl silane, amino silane or methacryloxy silane. Typical combinations include a combination of vinyl silane and amino silane, a combination of amino silane and methacryloxy silane, a combination of vinyl silane and methacryloxy silane, or a combination of vinyl silane, amino silane and methacryloxy silane, but is not limited thereto.

[0030] The silane coupling agent according to the present application can improve the dispersibility and adhesion of the filler in the resin, improve the compatibility between the inorganic filler and the resin, and improve the mechanical properties, electrical properties, and weather resistance of the filler.

[0031] Preferably, the mass of the silane coupling agent is 0.15 to 0.5 wt% of the iron-silicon alloy magnetic powder. For example, it may be 0.15 wt%, 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.4 wt% or 0.5 wt%, but is not limited to the enumerated values, and other unenumerated values within the numerical range are equally applicable.

[0032] Preferably, the method of organic insulation binding described in step (3) is to mix the binder solution with the passivated magnetic powder described in step (2), dry it, and sieve it.

[0033] Preferably, the binder in the binder solution contains a silicone resin.

[0034] Preferably, the silicone resin contains a high-temperature resistant silicone resin and / or a modified silicone resin, and is preferably a polymethyl silicone resin and / or a polysilane silicone resin.

[0035] The silicone resin according to the present application can improve the insulation performance of the powder, improve the compatibility between the inorganic filler and the resin, improve the powder moldability, and enhance the performance such as density.

[0036] Preferably, the solvent in the binder solution contains acetone.

[0037] Preferably, the mass of the binder in the binder solution is 0.3 to 1.5 wt% of the iron-silicon alloy magnetic powder. For example, it may be 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.8 wt%, 1 wt% or 1.5 wt%, but is not limited to the enumerated values, and other unenumerated values within the numerical range are equally applicable.

[0038] Preferably, the mass of the solvent in the binder solution is 1 to 5 times that of the binder. For example, it may be 1 time, 2 times, 3 times, 4 times or 5 times, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0039] Preferably, the mesh number of the sieve is 80 to 200 meshes. For example, it may be 80 meshes, 100 meshes, 150 meshes, 180 meshes or 200 meshes, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0040] Preferably, the release agent described in step (4) contains zinc stearate.

[0041] Preferably, the mass of the release agent described in step (4) is 0.3 to 0.5 wt% of the iron-silicon alloy magnetic powder. For example, it may be 0.3 wt%, 0.35 wt%, 0.4 wt%, 0.45 wt% or 0.5 wt%, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0042] Preferably, the pressure of the press molding described in step (5) is 1500 to 1800 MPa. For example, it may be 1500 MPa, 1550 MPa, 1600 MPa, 1700 MPa or 1800 MPa, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0043] Preferably, the maximum temperature of the annealing treatment described in step (5) is 680 to 730 °C. For example, it may be 680 °C, 690 °C, 700 °C, 710 °C, 720 °C or 730 °C, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0044] Preferably, the holding time of the annealing treatment described in step (5) is 25 to 35 min. For example, it may be 25 min, 28 min, 30 min, 32 min, or 35 min, but is not limited to the enumerated values, and other unenumerated values within the numerical range are equally applicable.

[0045] Preferably, after the annealing treatment described in step (5), it further includes cooling and coating with a paint coat layer.

[0046] Preferably, the paint material of the paint coat layer includes an epoxy resin.

[0047] As a preferred technical solution of the preparation method according to Embodiment 1 of the present application, the preparation method includes: Mixing iron-silicon alloy magnetic powder and organic aluminum aerosol, and baking at 75 to 85 °C to obtain surface-treated magnetic powder, wherein the mass of the organic aluminum aerosol is 0.5 to 1.5 wt% of the iron-silicon alloy magnetic powder (step (1)); Mixing an inactivator, deionized water, and the surface-treated magnetic powder described in step (1), and drying to obtain inactivated magnetic powder, wherein the inactivator is 0.15 to 2.5 wt% of the iron-silicon alloy magnetic powder, the mass of the deionized water is 1.5 to 3 times that of the inactivator, and the inactivator is phosphoric acid and / or aluminum dihydrogen phosphate (step (2)); Mixing a silane coupling agent of 0.15 to 0.5 wt% by mass of the iron-silicon alloy magnetic powder with the inactivated magnetic powder described in step (2), then mixing with a silicone resin-acetone solution, drying, and sieving through an 80- to 200-mesh sieve to obtain binder magnetic powder, wherein the mass of the silicone resin is 0.3 to 1.5 wt% of the iron-silicon alloy magnetic powder, and the mass of the acetone is 1 to 5 times that of the silicone resin (step (3)); Mixing zinc stearate of 0.3 to 0.5 wt% by mass of the iron-silicon alloy magnetic powder with the binder magnetic powder described in step (3) to obtain a mixed magnetic powder material (step (4)); After performing press molding on the mixed magnetic powder material described in step (4) at a pressure of 1500 - 1800 MPa, annealing treatment is carried out at a maximum temperature of 680 - 730 °C, the heat preservation time is 25 - 35 min, and after cooling, an epoxy resin coating layer is applied to obtain the iron-silicon compacted powder core in step (5). Among the iron-silicon alloy magnetic powders described in step (1), the mass with a particle size range of 75 - 150 μm accounts for 40 wt% or more of the total mass, the mass with a particle size range of 15 - 35 μm accounts for 30% or more of the total mass, and the remaining particle size range is 35 - 75 μm.

[0048] In Embodiment 2, the examples of the present application are obtained by the preparation method described in Embodiment 1 to provide an iron-silicon compacted powder core.

[0049] In Embodiment 3, the examples of the present application are to contain the iron-silicon compacted powder core described in Embodiment 2 to provide an inductor.

Advantages of the Invention

[0050] Compared with the related art, the examples of the present application have at least the following beneficial effects.

[0051] (1) The iron-silicon compacted powder core obtained by the preparation method according to the examples of the present application improves the inactivation and insulation effects, reduces the eddy current loss, and improves the problem that the loss increases after the temperature of the compacted powder core rises and the temperature rises too fast.

[0052] (2) The preparation method according to the examples of the present application has a simple process, does not require high requirements for equipment, and reduces the material cost.

[0053] Other aspects can be understood after reading and understanding the detailed description.

Modes for Carrying Out the Invention

[0054] To facilitate the understanding of this application, the following examples are enumerated. Those skilled in the art should understand that the above examples are merely for understanding this application and should not be regarded as specific limitations of this application.

Example

[0055] This example provides a method for preparing an iron-silicon compressed powder core, and the preparation method includes the following steps.

[0056] (1) Mix an iron-silicon alloy magnetic powder (with a silicon content of 5 wt% and the rest being iron) with an organoaluminum aerosol (Changhe JR14W, nanoaluminum aerosol) of 1 wt% by mass of the iron-silicon alloy magnetic powder, and perform baking at 80 °C to obtain a surface-treated magnetic powder.

[0057] Among the iron-silicon alloy magnetic powders, the mass with a particle size range of 75 - 150 μm accounts for 40 wt% of the total mass, the mass with a particle size range of 15 - 35 μm accounts for 30% of the total mass, and the remaining particle size range is 35 - 75 μm.

[0058] (2) Mix phosphoric acid, deionized water, and the surface-treated magnetic powder described in step (1), and dry to obtain an inactivated magnetic powder.

[0059] The mass of the phosphoric acid is 1 wt% of the iron-silicon alloy magnetic powder, and the mass of the deionized water is twice that of the phosphoric acid.

[0060] (3) Add a vinyl silane coupling agent of 0.25 wt% by mass of the iron-silicon alloy magnetic powder to the inactivated magnetic powder described in step (2), then mix with a silicone resin (domestic FJN-9802 high-temperature type silicone)-acetone solution, dry, and sieve through a 100-mesh sieve to obtain a bonded magnetic powder.

[0061] The mass of the silicone resin is 1 wt% of the iron-silicon alloy magnetic powder, and the mass of the acetone is three times that of the silicone resin.

[0062] (4) Mix zinc stearate accounting for 0.4 wt% of the iron-silicon alloy magnetic powder by mass with the binding magnetic powder described in step (3) to obtain a mixed magnetic powder material.

[0063] (5) Perform press molding on the mixed magnetic powder material described in step (4) at a pressure of 1700 MPa, then perform annealing treatment at a maximum temperature of 700 °C with a heat preservation time of 30 min. After cooling, coat an epoxy resin coating layer to obtain the iron-silicon compact magnetic core.

Example

[0064] This example provides a method for preparing an iron-silicon compact magnetic core, and the preparation method includes the following steps.

[0065] (1) Mix an iron-silicon alloy magnetic powder (with a silicon content of 4.5 wt% and the rest being iron) with an organic aluminum aerosol (Changhe JR14W, nano aluminum aerosol) accounting for 0.5 wt% of the iron-silicon alloy magnetic powder by mass, and bake at 85 °C to obtain a surface-treated magnetic powder.

[0066] Among the iron-silicon alloy magnetic powder, the mass with a particle size range of 75 - 150 μm accounts for 45 wt% of the total mass, the mass with a particle size range of 15 - 35 μm accounts for 35% of the total mass, and the remaining particle size range is 35 - 75 μm.

[0067] (2) Mix aluminum dihydrogen phosphate, deionized water, and the surface-treated magnetic powder described in step (1), and dry to obtain an inactivated magnetic powder.

[0068] The mass of the aluminum dihydrogen phosphate is 0.15 wt% of the iron-silicon alloy magnetic powder, and the mass of the deionized water is 1.5 times that of the aluminum dihydrogen phosphate.

[0069] (3) An aminosilane coupling agent with a mass of 0.15 wt% of the iron-silicon alloy magnetic powder was added to the passivated magnetic powder described in step (2), then mixed with a polymethyl silicone resin-acetone solution, dried, and sieved through an 80-mesh sieve to obtain the bonded magnetic powder.

[0070] The mass of the polymethyl silicone resin was 0.3 wt% of the iron-silicon alloy magnetic powder, and the mass of the acetone was 1 time that of the polymethyl silicone resin.

[0071] (4) Zinc stearate with a mass of 0.3 wt% of the iron-silicon alloy magnetic powder was mixed with the bonded magnetic powder described in step (3) to obtain a mixed magnetic powder material.

[0072] (5) The mixed magnetic powder material described in step (4) was subjected to press molding at a pressure of 1500 MPa, then annealed at a maximum temperature of 730 °C with a heat preservation time of 25 min. After cooling, an epoxy resin coating layer was applied to obtain the iron-silicon compact magnetic core.

Example

[0073] This example provides a method for preparing an iron-silicon compact magnetic core, and the preparation method includes the following steps.

[0074] (1) An iron-silicon alloy magnetic powder (with a silicon content of 6.5 wt% and the rest being iron) was mixed with an organoaluminum aerosol (Changhe JR14W, nanoaluminum aerosol) with a mass of 1.5 wt% of the iron-silicon alloy magnetic powder, and baked at 75 °C to obtain a surface-treated magnetic powder.

[0075] Among the iron-silicon alloy magnetic powder, the mass with a particle size range of 75 - 150 μm accounted for 42 wt% of the total mass, the mass with a particle size range of 15 - 35 μm accounted for 32% of the total mass, and the remaining particle size range was 35 - 75 μm.

[0076] (2) Phosphoric acid, deionized water, and the surface-treated magnetic powder described in step (1) were mixed and dried to obtain an inactivated magnetic powder.

[0077] The mass of the phosphoric acid was 2.5 wt% of the iron-silicon alloy magnetic powder, and the mass of the deionized water was three times that of the phosphoric acid.

[0078] (3) 0.5 wt% of a methacryloxy silane coupling agent based on the mass of the iron-silicon alloy magnetic powder was added to the inactivated magnetic powder described in step (2), and then mixed with a polysilane silicone resin-acetone solution, dried, and sieved through a 200-mesh sieve to obtain a bonded magnetic powder.

[0079] The mass of the polysilane silicone resin was 1.5 wt% of the iron-silicon alloy magnetic powder, and the mass of the acetone was five times that of the silicone resin.

[0080] (4) Zinc stearate with a mass of 0.5 wt% of the iron-silicon alloy magnetic powder and the bonded magnetic powder described in step (3) were mixed to obtain a mixed magnetic powder material.

[0081] (5) The mixed magnetic powder material described in step (4) was subjected to press molding at a pressure of 1800 MPa, followed by annealing treatment at a maximum temperature of 680 °C with a holding time of 35 min. After cooling, an epoxy resin coating layer was applied to obtain the iron-silicon compacted magnetic core.

Example

[0082] This example provides a method for preparing an iron-silicon compacted magnetic core. The difference from Example 1 is that among the iron-silicon alloy magnetic powders described in step (1), the mass with a particle size range of 75 - 150 μm accounts for 30 wt% of the total mass, the mass with a particle size range of 15 - 35 μm accounts for 30% of the total mass, and the remaining particle size range is 35 - 75 μm.

Example

[0083] This example provides a method for preparing an iron-silicon compacted powder core. The difference from Example 1 is only that among the iron-silicon alloy magnetic powders described in step (1), the mass with a particle size range of 75 - 150 μm accounts for 40 wt% of the total mass, the mass with a particle size range of 15 - 35 μm accounts for 20% of the total mass, and the remaining particle size range is 35 - 75 μm.

Example

[0084] This example provides a method for preparing an iron-silicon compacted powder core. The difference from Example 1 is only that in step (2), the mass of phosphoric acid is 0.1 wt% of the iron-silicon alloy magnetic powder.

Example

[0085] This example provides a method for preparing an iron-silicon compacted powder core. The difference from Example 1 is only that in step (2), the mass of phosphoric acid is 2.8 wt% of the iron-silicon alloy magnetic powder.

Example

[0086] This example provides a method for preparing an iron-silicon compacted powder core. The difference from Example 1 is only that in step (3), before mixing with the silicone resin-acetone solution, the operation of mixing with a silane coupling agent is not performed.

Example

[0087] This example provides a method for preparing an iron-silicon compacted powder core. The difference from Example 1 is only that in step (3), the mass of the silane coupling agent is 0.1 wt% of the iron-silicon alloy magnetic powder.

Example

[0088] This example provides a method for preparing an iron-silicon compacted powder core. The difference from Example 1 is only that in step (3), the mass of the silane coupling agent is 0.7 wt% of the iron-silicon alloy magnetic powder.

Example

[0089] This example provides a method for preparing an iron-silicon compacted powder core. The difference from Example 1 is only that in step (3), the mass of the silicone resin is 0.2 wt% of the iron-silicon alloy magnetic powder.

Example

[0090] This example provides a method for preparing an iron-silicon compacted powder core. The difference from Example 1 is only that in step (3), the mass of the silicone resin is 1.8 wt% of the iron-silicon alloy magnetic powder.

[0091] [Comparative Example 1] This comparative example provides a method for preparing an iron-silicon compacted powder core. The difference from Example 1 is only that in step (3), the silicone resin is replaced with an equal mass of glass powder (T800 glass powder manufactured by Anywhere Powder).

[0092] [Comparative Example 2] This comparative example provides a method for preparing an iron-silicon compacted powder core. The difference from Example 1 is only that in step (3), the silicone resin is replaced with an equal mass of silica.

[0093] The obtained iron-silicon compacted powder core was tested. Test conditions for inductance: 20 turns of winding, frequency 100 kHz. Test conditions for loss: 50 kHz, load 100 mT. Test temperature: 25 °C, 50 °C, 100 °C, 150 °C. With 22 turns + 22 turns of winding, the input and output were on the same winding. The test results are as shown in Tables 1 and 2 below.

[0094]

Table 1

[0095]

Table 2

[0096] From Tables 1 and 2, the following conclusions can be obtained.

[0097] (1) As can be seen from Examples 1 to 3, the iron-silicon compressed powder cores obtained by the preparation method according to the present application improve the inactivation and insulation effects, reduce the eddy current loss, and improve the problems that the loss increases after the temperature of the compressed powder core rises and the temperature rises too fast.

[0098] (2) As can be seen from the comparison between Example 4, Example 5 and Example 1, when the particle size range of the iron-silicon alloy magnetic powder was changed to exceed the preferred range of the present application, the loss of the compressed powder core increased, the quality decreased, and the amount of the compressed powder core within the range of 35 to 75 μm increased, resulting in an increase in the preparation cost.

[0099] (3) As can be seen from the comparison between Example 6, Example 7 and Example 1, when the mass of the inactivator in step (2) was changed to exceed the preferred range of the present application, the loss of the compressed powder core increased, and the inductance and quality of the compressed powder core decreased.

[0100] (4) As can be seen from the comparison between Example 8 and Example 1, when the silane coupling agent was not added in step (3), the loss of the compressed powder core increased and the quality of the compressed powder core decreased.

[0101] (5) As can be seen from the comparison between Example 9, Example 10 and Example 1, when the mass of the silane coupling agent in step (3) was not within the preferred range of the present application, the inductance and quality of the compressed powder core decreased, and the loss of the compressed powder core increased.

[0102] (6) As can be seen from the comparison between Example 11, Example 12 and Example 1, when the mass of the silicone resin in step (3) was not within the preferred range of the present application, the inductance and quality of the compressed powder core decreased, and the loss of the compressed powder core increased.

[0103] As can be seen from the comparison between Comparative Example 1, Comparative Example 2 and Example 1, when the organic binder is replaced with an inorganic binder in step (3), the inductance and quality of the powder compact core decrease, and the problem that the powder compact core has an increased temperature and an increased loss cannot be solved.

[0104] In summary, the iron-silicon powder compact core obtained by the preparation method according to the present application improves the inactivation and insulation effects, reduces the eddy current loss, improves the problem that the loss increases after the temperature of the powder compact core rises and the temperature rise is too fast. In addition, the preparation method according to the present application has a simple process, does not require high equipment, and reduces the material cost.

[0105] Although the detailed process flow of the present application has been described by the above embodiments, the present application is not limited to the above detailed process flow, that is, the present application does not necessarily mean that it cannot be implemented without relying on the above detailed process flow. Those skilled in the art should understand that any improvement to the present application, equivalent substitution of each raw material of the product of the present application, addition of auxiliary components, selection of specific forms, etc. are all included within the protection scope and disclosure scope of the present application.

Claims

1. Step (1) of obtaining surface-treated magnetic powder by mixing an iron-silicon alloy magnetic powder and a surface treatment agent; Step (2) of obtaining passivated magnetic powder by mixing a passivating agent, a solvent, and the surface-treated magnetic powder described in Step (1); Step (3) of performing organic insulation binding on the passivated magnetic powder described in Step (2) to obtain bound magnetic powder; Step (4) of obtaining a mixed magnetic powder material by mixing a release agent and the bound magnetic powder described in Step (3); Step (5) of obtaining an iron-silicon compacted magnetic core by performing press molding and annealing treatment on the mixed magnetic powder material described in Step (4), A method for preparing an iron-silicon compacted magnetic core.

2. The particle size range of the iron-silicon alloy magnetic powder described in Step (1) is 15 to 150 μm, The preparation method according to Claim 1.

3. Among the iron-silicon alloy magnetic powder described in Step (1), the mass of the particle size range of 75 to 150 μm accounts for 40 wt% or more of the total mass, The preparation method according to Claim 1 or 2.

4. Among the iron-silicon alloy magnetic powder described in Step (1), the mass of the particle size range of 15 to 35 μm accounts for 30% or more of the total mass, The preparation method according to any one of Claims 1 to 3.

5. The surface treatment agent described in Step (1) contains an organic aluminum aerosol, Preferably, the mass of the surface treatment agent described in Step (1) is 0.5 to 1.5 wt% of the iron-silicon alloy magnetic powder, Preferably, further baking is included after the mixing described in Step (1), Preferably, the temperature of the baking is 75 to 85 °C, The preparation method according to any one of Claims 1 to 4.

6. The passivating agent described in Step (2) contains a water-soluble inorganic material, preferably phosphoric acid and / or aluminum dihydrogen phosphate, Preferably, the mass of the passivating agent described in Step (2) is 0.15 to 2.5 wt% of the iron-silicon alloy magnetic powder, Preferably, the solvent described in Step (2) contains deionized water, Preferably, the mass of the solvent described in Step (2) is 1.5 to 3 times that of the passivating agent, Preferably, further drying is included after the mixing described in Step (2), The preparation method according to any one of Claims 1 to 5.

7. Before the organic insulating binding described in step (3), further comprising mixing a silane coupling agent and the passivated magnetic powder described in step (2), Preferably, the mass of the silane coupling agent is 0.15 to 0.5 wt% of the iron-silicon alloy magnetic powder, Preferably, the method of organic insulating binding described in step (3) is to mix a binder solution and the passivated magnetic powder described in step (2), dry and sieve, Preferably, the binder in the binder solution contains a silicone resin, Preferably, the solvent in the binder solution contains acetone, Preferably, the mass of the binder in the binder solution is 0.3 to 1.5 wt% of the iron-silicon alloy magnetic powder, Preferably, the mass of the solvent in the binder solution is 1 to 5 times that of the binder, Preferably, the mesh number of the sieve is 80 to 200 meshes, The preparation method according to any one of claims 1 to 6.

8. The release agent described in step (4) contains zinc stearate, Preferably, the mass of the release agent described in step (4) is 0.3 to 0.5 wt% of the iron-silicon alloy magnetic powder, The preparation method according to any one of claims 1 to 7.

9. The pressure of the press molding described in step (5) is 1500 to 1800 MPa, Preferably, the maximum temperature of the annealing treatment described in step (5) is 680 to 730 °C, Preferably, the heat preservation time of the annealing treatment described in step (5) is 25 to 35 min, The preparation method according to any one of claims 1 to 8.

10. After the annealing treatment described in step (5), further comprising cooling and coating a paint coat layer, Preferably, the paint material of the paint coat layer contains an epoxy resin, The preparation method according to any one of claims 1 to 9.

11. A step of mixing an iron-silicon alloy magnetic powder and an organic aluminum aerosol, baking at 75 to 85 °C to obtain a surface-treated magnetic powder, wherein the mass of the organic aluminum aerosol is 0.5 to 1.5 wt% of the iron-silicon alloy magnetic powder in step (1), A step of mixing an inactivator, deionized water, and the surface-treated magnetic powder described in step (1), and drying to obtain inactivated magnetic powder, wherein the inactivator is 0.15 to 2.5 wt% of the iron-silicon alloy magnetic powder, the mass of the deionized water is 1.5 to 3 times that of the inactivator, and the inactivator is phosphoric acid and / or aluminum dihydrogen phosphate (step (2)); A step of mixing a silane coupling agent of 0.15 to 0.5 wt% of the iron-silicon alloy magnetic powder by mass with the inactivated magnetic powder described in step (2), then mixing with a silicone resin-acetone solution, drying, and sieving through an 80-200 mesh sieve to obtain bonded magnetic powder, wherein the mass of the silicone resin is 0.3 to 1.5 wt% of the iron-silicon alloy magnetic powder, and the mass of the acetone is 1 to 5 times that of the silicone resin (step (3)); A step of mixing zinc stearate of 0.3 to 0.5 wt% of the iron-silicon alloy magnetic powder by mass with the bonded magnetic powder described in step (3) to obtain a mixed magnetic powder material (step (4)); A step of performing press molding on the mixed magnetic powder material described in step (4) at a pressure of 1500 to 1800 MPa, then performing annealing treatment at a maximum temperature of 680 to 730 °C, with a heat preservation time of 25 to 35 min, and coating an epoxy resin coating layer after cooling to obtain the iron-silicon compact magnetic core (step (5)), including: Among the iron-silicon alloy magnetic powders described in step (1), the mass of the particle size range of 75 to 150 μm accounts for 40 wt% or more of the total mass, the mass of the particle size range of 15 to 35 μm accounts for 30% or more of the total mass, and the remaining particle size range is 35 to 75 μm. The preparation method according to any one of claims 1 to 10.

12. Obtained by the preparation method according to any one of claims 1 to 11, Iron-silicon compact magnetic core.

13. Containing the iron-silicon compact magnetic core described in claim 12, Inductor.

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