Method of manufacturing pre-annealed inductors

Abstract

The application provides a preparation method of a pre-annealing processed inductor, which comprises the following steps: S1, obtaining amorphous nanocrystalline powder and performing insulation coating treatment on the amorphous nanocrystalline powder to obtain coated powder; S2, performing pre-annealing treatment on the obtained coated powder to promote the insulation passivation reaction of the coated powder; S3, performing forming treatment on the pre-annealing treated coated powder to obtain amorphous nanocrystalline insulation finished powder; and S4, performing press forming and baking solidification on the obtained amorphous nanocrystalline insulation finished powder to obtain an inductor. The application is applied to the preparation method, pre-annealing treatment is effectively performed on the coated powder, the stress generated in the preparation process of the coated powder is effectively released, the insulation passivation reaction of the coated powder is effectively promoted, and a dense and stable insulation coating layer is generated, and the performance of the prepared inductor is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soft magnetic alloy metallurgy, in particular to a preparation method of a pre-annealing processed inductor. BACKGROUND

[0002] Amorphous material has high saturation magnetic induction, high permeability, low coercivity, low high-frequency loss, good strength, wear resistance and corrosion resistance, good temperature and environmental stability, and excellent comprehensive performance. It replaces permalloy, silicon steel and ferrite, and is applied in power electronics technology, showing the characteristics of small size, high efficiency and energy saving, and has the best performance-price ratio among all metal soft magnetic materials.

[0003] In the prior art, carbonyl iron powder and iron-silicon-chromium powder are mainly used as raw materials for the preparation of integrally formed inductors. However, the above two powders have greater hysteresis loss, and the powder resistivity is low, resulting in greater eddy current loss during product application. Such products have high loss during application, causing product heating, energy efficiency reduction and other problems.

[0004] "Amorphous nanocrystalline" is a commonly used term in the field, referring to amorphous and nanocrystalline. In the field, based on different processing stages of the alloy, there are three forms in the conversion process from amorphous to nanocrystalline: amorphous, coexistence of amorphous and nanocrystalline, and nanocrystalline. Therefore, the description of "amorphous nanocrystalline" can be considered as a general concept of the three alloy forms: amorphous, amorphous and nanocrystalline, and nanocrystalline. SUMMARY

[0005] The present application aims to overcome the shortcomings of the prior art and provide a preparation method of a pre-annealing processed inductor.

[0006] The preparation method of the pre-annealing processed inductor comprises the following steps:

[0007] S1, obtaining amorphous nanocrystalline powder and performing insulation coating treatment to obtain coated powder;

[0008] S2, performing pre-annealing treatment on the obtained coated powder to promote the insulation passivation reaction of the coated powder;

[0009] S3, performing forming treatment on the pre-annealing treated coated powder to obtain amorphous nanocrystalline insulation finished powder;

[0010] S4, performing compression molding on the obtained amorphous nanocrystalline insulation finished powder and baking to obtain an inductor.

[0011] Further, the amorphous nanocrystalline powder composition comprises Fe 100-a-b-c-x-y-z Sia B b C c Mn x Cr y X Z , wherein X is any one of P, Cu, Mo, Ni, wherein 8≤a≤15, 6≤b≤12, 0.2≤c≤3.0, 0.1≤x≤3.5, 0.5≤y≤2.5, 0≤Z≤4.0.

[0012] Further, wherein 6≤b≤9, 0.3≤y≤2.5.

[0013] Further, the amorphous nanocrystalline powder component includes Fe 74.8 Si 11 B9C 1.5 Cr 2.5 Mn 0.2 P1 or Fe 74.8 Si 11 B9C 0.5 Cr 1.5 Mn 0.2 P2 or Fe 73.8 Si 11 B9C 1.5 Cr 1.5 Mn 0.2 P2 or Fe 79 Si 11 B7C 0.5 Cr 0.3 Mn 0.2 P2 or Fe 79 Si9B 6.2 C 0.5 Cr 0.3 Mn1P4; then in step S2, the temperature of the pre-annealing treatment is controlled to be 400-480 degrees Celsius.

[0014] Further, the amorphous nanocrystalline powder component includes Fe 74.8 Si 11 B9C 1.5 Cr 2.5 Mn 0.2 Mo1 or Fe 76.8 Si 11 B9C 0.5 Cr 1.5 Mn 0.2 Mo1 or Fe 73.8 Si 11 B9C 1.5 Cr 1.5 Mn 1.2 Mo1 or Fe 78 Si 11 B7C 0.5 Cr0.5 Mn1Mo2; then in step S2, the temperature of the pre-annealing process is controlled to be 420-520 degrees Celsius.

[0015] Further, the amorphous nanocrystalline powder component includes Fe 74.8 Si 11 B9C 1.5 Cr 2.5 Mn 0.2 Ni1or Fe 74.8 Si 11 B9C 0.5 Cr 1.5 Mn 0.2 Ni2or Fe 74.8 Si 11 B7C 1.5 Cr 1.5 Mn 0.2 Ni3or Fe 76.8 Si 11 B7C 0.5 Cr 0.5 Mn 0.2 Ni4; then in step S2, the temperature of the pre-annealing process is controlled to be 380-480 degrees Celsius.

[0016] Further, the annealing temperature range of the pre-annealing process is Tx-100 to Tx+80 degrees Celsius, and Tx is the crystallization temperature of the amorphous nanocrystalline.

[0017] Further, in step S1, the preparation method of the amorphous nanocrystalline powder is as follows:

[0018] S1-1, based on a preset component formula, selecting metal raw materials corresponding to the element components to be placed in a smelting furnace for smelting;

[0019] S1-2, after the above-mentioned metal raw materials are completely melted, alloy raw materials or non-metal raw materials corresponding to the element components are selected for secondary smelting;

[0020] S1-3, after the above-mentioned materials are completely melted, the obtained alloy melt is poured into a mold and then cooled and formed; to obtain an amorphous nanocrystalline master alloy;

[0021] S1-4, the obtained master alloy is subjected to powder preparation by a strip breaking method and / or an atomization powder preparation method, to obtain the amorphous nanocrystalline powder.

[0022] Further, in step S1, the process steps of the insulation coating process are as follows:

[0023] S1-1, the obtained amorphous nanocrystalline powder is mixed with a nitric acid solution and an acetone solution, and the obtained mixture is placed in a sealed container, heated in a water bath and subjected to a heat preservation treatment;

[0024] S1-2, after the mixture is fully reacted, the sealed container is opened to volatilize the acetone therein, and the coated powder is obtained.

[0025] After the coated powder is subjected to a pre-annealing treatment, the stress generated in the previous processes is released, and the formation of a dense and stable insulating coating layer is promoted.

[0026] Further, in step S4, the pressing forming process of the amorphous nanocrystalline insulating finished powder is as follows:

[0027] S4-1, the obtained amorphous nanocrystalline insulating finished powder is subjected to a heat treatment to heat the amorphous nanocrystalline insulating finished powder to 100-250 degrees Celsius;

[0028] S4-2, the amorphous nanocrystalline insulating finished powder heated to the target temperature is placed in a forming mold cavity for pressing forming.

[0029] The present application has the following advantages:

[0030] The present application is prepared by the method, which effectively releases the stress generated in the preparation process of the coated powder, effectively promotes the insulating passivation reaction of the coated powder, and generates a dense and stable insulating coating layer, thereby improving the performance of the inductor prepared. DETAILED DESCRIPTION

[0031] In order to make the technical solutions, objectives and advantages of the present application clearer, the following examples further explain and describe the present application.

[0032] The inductor preparation method of the present application specifically involves the following steps:

[0033] S1, the raw materials are blended and smelted according to the predetermined ingredient formula to prepare a master alloy;

[0034] S2, the obtained master alloy is powdered by a conventional strip-breaking and crushing method or an atomization method in the prior art to prepare an amorphous nanocrystalline powder, wherein the powder obtained by the strip-breaking and crushing method is in irregular sheet shape, and the powder obtained by the atomization method is in a spherical shape;

[0035] S3, the obtained amorphous nanocrystalline powder is subjected to an insulating coating treatment to obtain a coated powder;

[0036] S4, performing a forming treatment on the obtained coated powder to granulate the corresponding powder to obtain an amorphous nanocrystalline insulating finished powder;

[0037] The forming treatment process comprises adding a binder to the coated powder for secondary coating treatment to obtain a semi-finished powder; and then adding a lubricant to the semi-finished powder and stirring to mix to granulate the corresponding powder to obtain the insulating finished powder;

[0038] S5, performing a pressing forming and baking curing on the obtained insulating finished powder, and performing subsequent processing to obtain the inductor.

[0039] Embodiment 1:

[0040] Based on the application of step S1, the alloy composition prepared by the preset component formula of the present application comprises Fe 100-a-b-c-x-y-z Si a B b C c Mn x Cr y X Z , wherein X is any one of P, Cu, Mo, and Ni, 8≤a≤15, 6≤b≤12, 0.2≤c≤3.0, 0.1≤x≤3.5, 0.5≤y≤2.5, and 0≤Z≤4.0. Preferably, 6≤b≤9, 0.3≤y≤2.5.

[0041] The alloy composition of the master alloy can make the subsequently prepared powder have high amorphous forming ability, strong corrosion resistance, high saturation magnetic induction strength, and low coercive force, and the application has good application prospects.

[0042] The above alloy composition scheme is preferably applied to Fe 74.8 Si 11 B9C 1.5 Cr 2.5 Mn 0.2 P1 or Fe 74.8 Si 11 B9C 0.5 Cr 1.5 Mn 0.2 P2 or Fe 73.8 Si 11 B9C 1.5 Cr 1.5 Mn 0.2 P2 or Fe 79 Si 11 B7C 0.5 Cr 0.3 Mn 0.2 P2 or Fe 79 Si9B 6.2 C0.5 Cr 0.3 Mn1P4.

[0043] Specifically, the smelting process of the master alloy is as follows:

[0044] S1-1, select industrial pure iron, nodular iron and electrolytic chromium, metal manganese and other metal raw materials, put into the smelting furnace for smelting, the smelting temperature is 1350-1550 degrees Celsius, the smelting time is 1.5-3.5h;

[0045] S1-2, after smelting the above materials to completely melt, add alloy raw materials and non-metallic raw materials such as boron iron, phosphorus iron and industrial silicon in turn for secondary smelting;

[0046] S1-3, after the secondary smelting of the above materials is completely melted, keep warm for 10min;

[0047] S1-4, after the molten metal is cooled to 1350 degrees Celsius, open the smelting furnace and remove the surface impurities of the alloy melt;

[0048] S1-5, the alloy melt after removing the surface impurities is poured into the ingot mold, and then cooled to form, so as to obtain the master alloy.

[0049] Among them, the smelting furnace is preferably a vacuum smelting furnace, and the furnace loading capacity is 15-35kg.

[0050] And based on the application of step S2, the master alloy with specific alloy composition can be used to prepare corresponding amorphous nanocrystalline strip products, amorphous nanocrystalline broken powder products in sheet shape and amorphous nanocrystalline atomized powder products in spherical shape.

[0051] As shown in Table 1, the strip prepared from the master alloy will have the following performance characteristics.

[0052] Table 1 (test performance of amorphous nanocrystalline strip with different components)

[0053]

[0054] As shown in Table 2, the strip prepared from the master alloy is broken into powder, and the magnetic powder core prepared by the prior art magnetic powder core preparation method will have the following performance characteristics.

[0055] Table 2 (test performance of magnetic powder core prepared from amorphous nanocrystalline broken powder with different components)

[0056]

[0057] And as shown in Table 3, based on the prior art gas atomization or water atomization or water-gas atomization combined method, the performance of the atomized powder prepared from the master alloy will be evaluated by the press ring method, and the performance evaluation results will have the following performance characteristics.

[0058] Table 3 (Comparison of performance of amorphous nanocrystalline atomized powder and conventional powder in press ring test)

[0059]

[0060]

[0061] And as shown in Table 4, based on the application of the alloy composition, the performance evaluation results of the atomized powder prepared from different components will have the following performance characteristics.

[0062] Table 4 (Comparison of performance of amorphous nanocrystalline atomized powder in press ring test with different components)

[0063]

[0064] Example 2:

[0065] The difference between this embodiment and the above-mentioned embodiment 1 is that the alloy composition scheme is preferably applied as Fe 74.8 Si 11 B9C 1.5 Cr 2.5 Mn 0.2 Mo1 or Fe 76.8 Si 11 B9C 0.5 Cr 1.5 Mn 0.2 Mo1 or Fe 73.8 Si 11 B9C 1.5 Cr 1.5 Mn 1.2 Mo1 or Fe 78 Si 11 B7C 0.5 Cr 0.5 Mn1Mo2.

[0066] Specifically, the smelting process of the master alloy is as follows:

[0067] S1-1, select industrial pure iron, nodular iron, electrolytic chromium, metal manganese, electrolytic molybdenum and other metal raw materials, and put them into a smelting furnace for smelting, the smelting temperature is 1350-1550 degrees Celsius, and the smelting time is 1.5-3.5 hours;

[0068] S1-2, after smelting the above materials to complete melting, alloy raw materials and non-metallic raw materials such as boron iron and industrial silicon are added in turn for secondary smelting;

[0069] S1-3, after the above materials are completely melted for secondary smelting, heat preservation is performed for 10 minutes;

[0070] S1-4, after the molten metal after melting is cooled to 1350 degrees Celsius, the smelting furnace is started, and the surface impurities of the alloy melt are removed;

[0071] S1-5, the alloy melt after removing the surface impurities is poured into a ingot mold, and then cooled and formed to obtain the master alloy.

[0072] Preferably, the smelting furnace is a vacuum smelting furnace, and the furnace loading capacity is 15-35 kg.

[0073] Based on the application of step S2, the master alloy with the specific alloy composition can be used to prepare corresponding amorphous nanocrystalline strip products, amorphous nanocrystalline broken powder products in sheet form, and amorphous nanocrystalline atomized powder products in spherical form.

[0074] As shown in Table 5, the strip prepared from the master alloy will have the following performance characteristics.

[0075] Table 5 (Test performance of amorphous nanocrystalline strip with different compositions)

[0076]

[0077] As shown in Table 6, the strip prepared from the master alloy is broken into powder, and the magnetic powder core is prepared by the magnetic powder core preparation method of the prior art. The magnetic powder core prepared will have the following performance characteristics.

[0078] Table 6 (Test performance of magnetic powder core prepared from amorphous nanocrystalline broken powder with different compositions)

[0079]

[0080] As shown in Table 7, based on the gas atomization or water atomization or water-gas combined atomization method of the prior art, the performance of the atomized powder prepared from the master alloy is evaluated by the compression ring method. The performance evaluation results will have the following performance characteristics.

[0081] Table 7 (Comparison of compression ring test performance of amorphous nanocrystalline atomized powder and conventional powder)

[0082]

[0083] As shown in Table 8, based on the application of the alloy composition, the atomized powder prepared from different compositions is evaluated according to the one-piece inductive evaluation method. The performance evaluation results will have the following performance characteristics.

[0084] Table 8 (Performance comparison of different component amorphous nanocrystalline atomized powder according to one-body inductance evaluation mode)

[0085]

[0086] Example 3:

[0087] The difference between this embodiment and the above-mentioned Example 1 is that the alloy component scheme is preferably applied as: Fe 74.8 Si 11 B9C 1.5 Cr 2.5 Mn 0.2 Ni1or Fe 75.8 Si 11 B9C 0.5 Cr 1.5 Mn 0.2 Ni2or Fe 75.8 Si 11 B7C 1.5 Cr 1.5 Mn 0.2 Ni3or Fe 76.8 Si 11 B7C 0.5 Cr 0.5 Mn 0.2 Ni4.

[0088] Specifically, the smelting process of the master alloy is as follows:

[0089] S1-1, select industrial pure iron, nodular iron, and electrolytic chromium, metal manganese, electrolytic nickel, and other metal raw materials, and place them into a smelting furnace for smelting, with a smelting temperature of 1350-1550 degrees Celsius and a smelting time of 1.5-3.5 hours;

[0090] S1-2, after smelting the above-mentioned materials to complete melting, alloy raw materials and non-metal raw materials such as boron iron and industrial silicon are sequentially added for secondary smelting;

[0091] S1-3, after the above-mentioned materials are completely melted during secondary smelting, keep warm for 10 minutes;

[0092] S1-4, after the molten metal is cooled to 1350 degrees Celsius, the smelting furnace is opened, and the surface impurities of the alloy melt are removed;

[0093] S1-5, the alloy melt after removing the surface impurities is poured into a ingot mold, and then cooled and formed to obtain the master alloy.

[0094] The smelting furnace used is preferably a vacuum smelting furnace, and the charging capacity is 15-35 kg.

[0095] And based on the application of step S2, with the master alloy having the specific alloy composition, the corresponding amorphous nanocrystalline strip product, amorphous nanocrystalline broken powder product in sheet form and amorphous nanocrystalline atomized powder product in spherical form can be prepared.

[0096] Then as shown in Table 9, the strip prepared from the master alloy will have the following performance characteristics.

[0097] Table 9 (Test performance of amorphous nanocrystalline strip with different compositions)

[0098]

[0099]

[0100] And as shown in Table 10, the strip prepared from the master alloy is broken into powder, and through the existing technology of magnetic powder core preparation method, the magnetic powder core prepared will have the following performance characteristics.

[0101] Table 10 (Test performance of magnetic powder core prepared from amorphous nanocrystalline broken powder with different compositions)

[0102]

[0103] And as shown in Table 11, based on the existing technology of gas atomization or water atomization or water-gas combined atomization method, the performance of the atomized powder prepared from the master alloy will be evaluated by the compression ring method, and the performance evaluation results will have the following performance characteristics.

[0104] Table 11 (Comparison of test performance of amorphous nanocrystalline atomized powder and conventional powder by compression ring)

[0105]

[0106] And as shown in Table 12, based on the application of the alloy composition, the atomized powder prepared from different compositions is evaluated according to the one-piece inductor evaluation method, and the performance evaluation results will have the following performance characteristics.

[0107] Table 12 (Comparison of performance of amorphous nanocrystalline atomized powder with different compositions according to the one-piece inductor evaluation method)

[0108]

[0109] Example 4:

[0110] Based on the above application of the embodiments 1 to 3, in order to optimize the powder flowability and bulk density, the atomized powder prepared in the step S2 can be dried and classified to be applied in different mesh levels. As a preferred embodiment, the atomized powder is divided into three levels of -800 mesh, -500 mesh and -325 mesh; the powder ratio is preferably -800:-500:-325=1:3:6; the powder mixing is preferably ultrasonic dispersion; and the powder bulk density is 3.2-4.5 g / cm3.

[0111] In the following Table 13, the performance difference of different powder ratios is listed according to the evaluation method of the integrally formed inductor.

[0112] Table 13 (Comparison of Performance of Pressure Ring Test of Different Powder Ratios)

[0113]

[0114] Based on the application of the atomized powder in the present application, since the shape of the atomized powder is spherical, there are many gaps between the powders. Therefore, the performance of the inductor product produced directly from the atomized powder is still limited.

[0115] In the present embodiment, before the insulating coating treatment of the obtained amorphous nanocrystalline atomized powder in the step S3, a filler powder is added for sufficient stirring and mixing. The filler powder is selected to be iron-silicon-chromium and / or carbonyl iron powder, so that the gaps between the amorphous nanocrystalline atomized powders are filled to form an amorphous nanocrystalline mixed powder, thereby effectively increasing the bonding strength between the powder particles, effectively improving the density of the subsequent product, and improving the performance of the product.

[0116] In the application of the amorphous nanocrystalline mixed powder, the particle size range of the atomized powder used is -325 to +500 mesh, and the particle size range of the filler powder is -600 to 800 mesh. The addition ratio of the filler powder to the whole amorphous nanocrystalline mixed powder is 2-15%.

[0117] In the following Tables 14 and 15, the comparison results of the performance of the pressure ring test under different ratios of amorphous nanocrystalline powder, iron-silicon-chromium powder and carbonyl iron powder are listed.

[0118] Table 14 (Comparison of Performance of Pressure Ring Test of Amorphous Nanocrystalline Powder and Iron-Silicon-Chromium Powder)

[0119]

[0120] Table 15 (non-crystalline nanocrystalline powder and carbonyl iron powder ratio compression ring test performance comparison)

[0121]

[0122] Example 5:

[0123] And based on the application of step S3, the present application will further provide an insulation coating process to meet the preparation needs of coated powder, the specific process steps are as follows:

[0124] A1, the obtained non-crystalline nanocrystalline powder is mixed with nitric acid solution and acetone solution, and the obtained mixture is placed in a sealed container, heated with water bath constant temperature and treated with water bath constant temperature; the heating temperature of the water bath constant temperature is preferably 45 degrees Celsius; the heat preservation time is preferably 30 minutes.

[0125] A2, the mixture in the sealed container is stirred to make the mixture in it react fully; the stirring treatment can be selected as fully stirring the mixture in the sealed container with a magnetic stirrer or outputting ultrasonic waves to the inside of the sealed container to make the mixture dispersed and mixed by ultrasonic waves; based on the application of nitric acid solution as a passivator, a uniform oxide film is formed on the surface of the non-crystalline nanocrystalline powder to form a coated powder.

[0126] A3, after sufficient reaction, open the sealed container and let the acetone volatilize outward; take out the coated powder.

[0127] Among them, as a preferred embodiment, based on the mass of the non-crystalline nanocrystalline powder, the mass ratio of the nitric acid solution to the non-crystalline nanocrystalline powder is 1.2-2.4wt%, and the nitric acid solution can be selected as concentrated nitric acid with a concentration of 68%; the mass ratio of the acetone solution to the non-crystalline nanocrystalline powder is 30-40wt%. In this process, there is no corresponding nitric acid reaction waste liquid, and no environmental pollution is caused.

[0128] In the above process, the binder material selected is a mixture of organic silicon resin, epoxy resin and curing agent, and the ratio by mass fraction is organic silicon resin: epoxy resin: curing agent = 14.5:3:1. The mass ratio of the binder material to the non-crystalline nanocrystalline powder is 1.0-5wt%.

[0129] In the above process, the lubricant used is zinc stearate.

[0130] In the above process, the compression molding pressure is controlled at 500-800Mpa.

[0131] Example 6:

[0132] After the coated powder is obtained, the present application applies a pre-annealing treatment to effectively promote the insulation coating effect of the powder, effectively remove the stress generated during the powder preparation process and insulation stirring process, and volatilize harmful substances introduced during the insulation coating process.

[0133] The obtained coated powder is then subjected to a pre-annealing treatment, and the annealing temperature range of the pre-annealing treatment is Tx-100 to Tx+80 degrees Celsius, and Tx is the crystallization temperature of the amorphous nanocrystalline.

[0134] For nanocrystalline powders, the formation of ultrafine crystals in the powder can be achieved, and the pre-annealing temperature selected is 420-570°C, and the annealing time is 30-80 min.

[0135] As shown in Tables 16 to 18, based on the application of the corresponding alloy composition, the coated powders prepared from different compositions have the following performance characteristics through different pre-annealing temperatures.

[0136] Note: The loss test conditions of the sample are 100 kHz, 100 mT, and the test result unit is kw / m3.

[0137] Table 16 (Comparison of performance of coated powders with different compositions and different pre-annealing temperatures in ring compression tests)

[0138]

[0139]

[0140] Table 17 (Comparison of performance of coated powders with different compositions and different pre-annealing temperatures in ring compression tests)

[0141]

[0142] Table 18 (Comparison of performance of coated powders with different compositions and different pre-annealing temperatures in ring compression tests)

[0143]

[0144] After the pre-annealing treatment of the coated powder, the coated powder is subjected to a molding process to obtain an insulating finished powder. Specifically, during the secondary coating process, the binder used is epoxy resin, silicone resin, inorganic silicon, etc., and the diluent can be selected from acetone, ethanol, pure water, etc. The proportion of the binder is 0.5-5.0%, and the proportion of the diluent is 0.5-10%. Preferably, the proportion of the binder is 1.2-3.0%, and the proportion of the diluent is 3-10%. The uniform mixing process can be carried out at room temperature or under heating, and the heating temperature is preferably 50-120°C.

[0145] The lubricant can be selected from paraffin, zinc stearate, magnesium stearate, etc., and the addition ratio is 0.2-1.5%. After mixing, the insulating finished powder is obtained.

[0146] Example 7:

[0147] In the application process of step S5, in order to simplify the pressing process of the inductor, the application improves the pressing process for the structure of the integrated inductor.

[0148] Specifically, the obtained amorphous nanocrystalline insulating finished powder is heated and further stirred and mixed, so that the obtained amorphous nanocrystalline insulating finished powder is uniformly heated; the amorphous nanocrystalline insulating finished powder is heated to 100-250 degrees Celsius, and then is kept warm for standby.

[0149] After the corresponding forming cavity is prepared, a preformed coil is designed for the inductor, the preformed coil is placed in the forming cavity, and the heated amorphous nanocrystalline insulating finished powder is filled in the forming cavity. The inductor is pressed by a conventional cold pressing equipment to obtain an integrated inductor blank. In the pressing process, the pressure range is 400-800 Mpa.

[0150] The following Table 19 shows the performance difference of the amorphous nanocrystalline insulating finished powder under different heating temperatures when cold-pressed by the cold-pressing equipment.

[0151] Table 19 (Performance comparison of powder temperature pressing ring test)

[0152]

[0153] Then, the obtained integrated inductor blank is baked at a temperature of 150-220 degrees Celsius for 1-2.5 hours. According to the design needs of the specific product, the leg part of the inductor is bent, and the inductor is obtained.

[0154] Further, in order to improve the magnetic permeability of the product and reduce the deformation of the coil, a step-by-step forming combination method can be selected to prepare the inductor.

[0155] For example, for an inductor product using a T-shaped preformed magnet and a U-shaped preformed magnet combination, corresponding T-shaped forming cavities and U-shaped forming cavities can be set according to the structural characteristics. The heated amorphous nanocrystalline insulating finished powder is filled into the corresponding forming cavities to prepare the T-shaped preformed magnet and the U-shaped preformed magnet. Then, the coil is placed in the gap between the T-shaped preformed magnet and the U-shaped preformed magnet, and the powder is further filled for secondary pressing to obtain the corresponding inductor product.

[0156] On the other hand, after the coil is put into the gap between the T-shaped preformed magnet and the U-shaped preformed magnet, the two can be bonded at the contact boundary by using magnetic glue to fill the gap in the product, and the required inductor product is obtained.

[0157] Based on the definition of the concept of "amorphous nanocrystalline", the above-mentioned related amorphous nanocrystalline alloy products can be considered as applications of corresponding amorphous alloy products, amorphous and nanocrystalline alloy products or nanocrystalline alloy products.

[0158] The above only describes the preferred embodiments of the present application, and for those skilled in the art, the embodiments can still be modified without departing from the implementation principle of the present application, and the corresponding modification scheme should also be considered as the protection scope of the present application.

Claims

1. A method for preparing a pre-annealed inductor, characterized in that, Includes the following steps: S1. Obtain amorphous nanocrystalline powder and perform insulating coating treatment on it to obtain coated powder; S2. The obtained coated powder is pre-annealed to promote the insulating passivation reaction of the coated powder; S3. The coated powder obtained from the pre-annealing treatment is subjected to molding treatment to obtain amorphous nanocrystalline insulating finished powder. S4. The obtained amorphous nanocrystalline insulating powder is pressed and baked to solidify in order to obtain an inductor. The amorphous nanocrystalline powder composition includes Fe. 74.8 Si 11 B9C 1.5 Cr 2.5 Mn 0.2 P1 or Fe 74.8 Si 11 B9C 0.5 Cr 1.5 Mn 0.2 P2 or Fe 73.8 Si 11 B9C 1.5 Cr 1.5 Mn 0.2 P2 or Fe 79 Si 11 B7C 0.5 Cr 0.3 Mn 0.2 P2 or Fe 79 Si9B 6.2 C 0.5 Cr 0.3 Mn1P4; then in step S2, the temperature of the pre-annealing treatment is controlled at 400-480 degrees Celsius; Alternatively, the amorphous nanocrystalline powder may contain Fe. 74.8 Si 11 B9C 1.5 Cr 2.5 Mn 0.2 Mo1 or Fe 76.8 Si 11 B9C 0.5 Cr 1.5 Mn 0.2 Mo1 or Fe 73.8 Si 11 B9C 1.5 Cr 1.5 Mn 1.2 Mo1 or Fe 78 Si 11 B7C 0.5 Cr 0.5 Mn1Mo2; then in step S2, the temperature of the pre-annealing treatment is controlled at 420 to 520 degrees Celsius; Alternatively, the amorphous nanocrystalline powder may contain Fe. 74.8 Si 11 B9C 1.5 Cr 2.5 Mn 0.2 Ni1 or Fe 74.8 Si 11 B9C 0.5 Cr 1.5 Mn 0.2 Ni2 or Fe 74.8 Si 11 B7C 1.5 Cr 1.5 Mn 0.2 Ni3 or Fe 76.8 Si 11 B7C 0.5 Cr 0.5 Mn 0.2 Ni4; then in step S2, the temperature of the pre-annealing treatment is controlled at 380 to 480 degrees Celsius.

2. The preparation method according to claim 1, characterized in that, In step S1, the amorphous nanocrystalline powder is prepared as follows: S1-1. Based on the preset composition formula, select metal raw materials with corresponding elemental components and place them into the smelting furnace for smelting. S1-2. After the above-mentioned metal raw materials are smelted to complete melting, alloy raw materials or non-metallic raw materials with corresponding elemental compositions are selected for secondary smelting. S1-3. After the above materials have been completely melted in the secondary smelting, the resulting alloy melt is poured into a mold and then cooled and shaped to obtain an amorphous nanocrystalline master alloy. S1-4. The obtained master alloy is subjected to a strip crushing method and / or atomization powder preparation method to obtain the amorphous nanocrystalline powder.

3. The preparation method according to claim 1, characterized in that, In step S1, the insulation coating process includes the following steps: S1-1. Mix the obtained amorphous nanocrystalline powder with nitric acid solution and acetone solution. Place the mixture in a sealed container and heat it in a water bath at a constant temperature and keep it warm. S1-2. After the mixture has reacted fully, open the sealed container to allow the acetone to evaporate and obtain the coated powder. After the coating powder undergoes pre-annealing treatment, the stress generated in the previous processes is released, and a dense and stable insulating coating layer is formed.

4. The preparation method according to claim 1, characterized in that, In step S4, the pressing and molding process of the amorphous nanocrystalline insulating powder is as follows: S4-1. Heat the obtained amorphous nanocrystalline insulating powder to raise its temperature to 100-250 degrees Celsius. S4-2. The amorphous nanocrystalline insulating powder, heated to the target temperature, is placed into the molding cavity for pressing and molding.

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