CN112851327A

CN112851327A - Low-loss tantalum-silicon composite manganese-zinc-doped ferrite material and preparation method thereof

Info

Publication number: CN112851327A
Application number: CN202110206248.3A
Authority: CN
Inventors: 江昊杰; 严鹏飞; 严彪
Original assignee: Tongji University
Current assignee: Tongji University
Priority date: 2021-02-24
Filing date: 2021-02-24
Publication date: 2021-05-28

Abstract

The invention relates to a low-loss tantalum-silicon composite manganese-zinc-doped ferrite material and a preparation method thereof, wherein the material comprises a main material and a doping material, the main material comprises ferric oxide, manganese oxide and zinc oxide, the mass ratio of the ferric oxide to the manganese oxide to the zinc oxide is (68-71): 20-25): 6-9, and the doping material comprises tantalum and silicon. The preparation method comprises the following steps: s1: adding the main material into a ball mill for ball milling to obtain a mixture A; s2: pre-burning the mixture A, and then cooling to room temperature to obtain a pre-burned material B; s3: adding the pre-sintered material B and the doping material into a ball mill for secondary ball milling, and then drying to obtain a mixture C; s4: adding a polyvinyl alcohol solution into the mixture C, mixing, performing spray granulation, and sieving to obtain powder particles; s5: putting the powder particles into a die for compression molding to obtain a blank; s6: and sintering the blank under an equilibrium atmosphere. Compared with the prior art, the material has higher saturation magnetic flux density and lower high-frequency loss.

Description

Low-loss tantalum-silicon composite manganese-zinc-doped ferrite material and preparation method thereof

Technical Field

The invention belongs to the technical field of magnetic materials, and particularly relates to a low-loss tantalum-silicon composite manganese-zinc-doped ferrite material and a preparation method thereof.

Background

The manganese-zinc ferrite serving as one soft magnetic material is widely applied to the fields of power industrial equipment, household appliances, informatization technology and the like, is the soft magnetic material with the largest output and the largest consumption at present, and has irreplaceable effects in megahertz-level electronic components. With the development of communication technology and electronic product digitization, new requirements are put forward on soft magnetic ferrite and elements, and the high-performance and high-permeability magnetic core is widely applied to various basic materials for telecommunication and information, such as common mode filters, saturated inductors, current transformers, leakage protectors, insulating transformers, signal and pulse transformers and the like. The existing electronic communication industry needs ferrite magnetic cores with low magnetic core loss and high magnetic permeability to meet the requirements of miniaturization and high efficiency of the existing electrical equipment, and the existing magnetic core materials are difficult to meet the requirements.

Patent CN104058739B discloses a tantalum-based ferrite core material for a transformer, which comprises main materials and additives, wherein the main materials comprise the following components in a molar ratio: 57.1-64mol of Fe2O3, 16.2-20mol of manganese oxide, 10.1-15mol of zinc oxide, 4-5.2mol of copper oxide, 0.2-1mol of zinc borate, 1-1.3mol of barium oxide and 0.01-0.02mol of rare earth composite magnetic conductive powder; the additive comprises the following components in percentage by weight of the ferrite core material: 30-50ppm of aluminum tripolyphosphate, 10-20ppm of titanium tetrachloride and 40-50ppm of silicon micropowder. Besides the main materials, the material contains more components such as adhesives, powder dispersants and the like, and if the materials are controlled improperly in the subsequent sintering process, the defects are easy to occur, and the qualified rate of finished products is difficult to guarantee. The invention does not give a corresponding process, and only from the performance of the final magnetic core, the loss at 100kHz is close to 400W/m³It is difficult to apply at megahertz level.

Patent CN106278229A discloses a high-frequency high-permeability multipurpose manganese-zinc ferrite material, which is prepared from the following raw materials in parts by weight: 60-65 parts of hydroxyl iron powder, 10-15 parts of ferric oxide, 25-27 parts of manganese oxide, 21-23 parts of zinc oxide, 5-5 parts of silane coupling agent kh5704-5 parts of organic silicon resin, 1-2 parts of polyvinyl alcohol, 7-9 parts of sodium silicate, 0.4-0.5 part of tantalum carbide, 0.3-0.4 part of ceramic powder, 0.8-0.9 part of copper oxide and a proper amount of water. The material takes the hydroxyl iron powder as a raw material, although the saturation magnetic induction intensity is high, the Curie temperature is low (only 170 ℃), the application frequency is only 120kHz, and the loss is high (more than 400W/m)³) No detailed magnetic conductivity data is given, and the high saturation magnetic induction intensity is high after the miniaturization of productsThe advantage of the degree cannot be reflected at high frequencies.

Disclosure of Invention

The invention aims to solve the problems and provide a low-loss tantalum-silicon composite doped manganese-zinc ferrite material and a preparation method thereof.

The purpose of the invention is realized by the following technical scheme:

the low-loss tantalum-silicon composite manganese-zinc-doped ferrite material comprises a main material and a doping material, wherein the main material comprises ferric oxide, manganese oxide and zinc oxide, the mass ratio of the ferric oxide to the manganese oxide to the zinc oxide is (68-71): (20-25): (6-9), and the doping material comprises a tantalum simple substance and a silicon simple substance. The tantalum-silicon composite manganese-zinc-doped ferrite material has relatively high initial permeability (2800-3450), high saturation magnetic flux density (0.50-0.53T), relatively proper Curie temperature (220-260 ℃) and relatively low high frequency loss (305-340 kW/m)³)。

In the material, the total amount of the doping materials is 200-380 PPM (PPM), specifically, the content of tantalum is 100-300 PPM, preferably 100-200 PPM, the content of silicon is 100-200 PPM, preferably 100-180 PPM, and the total mass of the raw materials of the material is 100 wt%.

The material also comprises an auxiliary material, wherein the auxiliary material comprises one or a mixture of more of vanadium pentoxide, niobium pentoxide, bismuth oxide, cobalt oxide, molybdenum oxide or calcium carbonate.

In the material, the total content of the auxiliary materials is 500-2000 PPM (parts per million), preferably 600-800 PPM, and the total mass of the raw materials of the material is 100 wt%, specifically, the content of vanadium pentoxide, niobium pentoxide, bismuth oxide, cobalt oxide, molybdenum oxide and calcium carbonate is 100-150 PPM, 0-150 PPM, 100-200 PPM, 0-100 PPM and 100-150 PPM respectively.

A preparation method of the tantalum-silicon composite doped manganese-zinc ferrite material specifically comprises the following steps:

s1: adding iron oxide, manganese oxide and zinc oxide into a ball mill for ball milling to obtain a mixture A;

s2: pre-burning the mixture A, and then cooling to room temperature to obtain a pre-burned material B;

s3: adding the pre-sintered material B and the doping material into a ball mill for secondary ball milling, and then drying to obtain a mixture C, wherein when the material contains an auxiliary material, the auxiliary material also needs to be added into the ball mill;

s4: adding a polyvinyl alcohol solution into the mixture C, mixing, performing spray granulation, and sieving to obtain powder particles, wherein the polyvinyl alcohol plays a role of a binder and is not remained in the material after sintering;

s5: putting the powder particles into a die, and performing compression molding to obtain a blank;

s6: and sintering the blank in a balanced atmosphere to obtain the tantalum-silicon composite doped manganese-zinc ferrite material.

In step S1, the rotation speed of the ball mill is 200 to 250r/min, preferably 200 to 230r/min, and the ball milling time is 2 to 4 hours. The sufficient ball milling can ensure that the main materials are mutually extruded and crushed, so that the powder particles form higher surface energy, partial ferrite phase is formed in the subsequent pre-sintering process, and the deformation abnormity of the subsequent sintering is improved. Meanwhile, the doping materials and the auxiliary materials can be uniformly distributed on the surfaces of the main material particles or mutually crushed and combined, and the function of the main material particles in the subsequent sintering reaction is favorably realized.

In step S2, pre-sintering is carried out in air atmosphere, the pre-sintering temperature is 850-900 ℃, preferably 860-880 ℃, and the pre-sintering time is 50-90 min, preferably 55-60 min.

In step S3, the rotation speed of the ball mill is 200-250 r/min, preferably 200-230 r/min, the ball milling time is 8-10 h, the drying temperature is 70-80 ℃, preferably 80 ℃, and the drying time is 20-24 h, preferably 24 h.

In step S3, the elemental silicon is added in powder form.

In step S4, the mixture is sprayed and granulated and then sieved by a 100-120-mesh sieve.

In step S5, a constant-load press is used to perform press forming, the load applied by the constant-load press is 400 to 500MPa, preferably 450MPa, and the pressure is maintained for 340 to 380 seconds, preferably 360 seconds.

In step S6, the sintering process specifically includes: the method comprises the steps of firstly heating to 400 ℃ at a speed of 2 ℃/min under a vacuum condition, then heating to 600 ℃ at a speed of 5 ℃/min, then heating to 1200 ℃ at a speed of 3 ℃/min under a high-purity nitrogen atmosphere, then filling air to adjust to 5% oxygen partial pressure, heating to 1250-1315 ℃ at a speed of 1 ℃/min, preferably 1260-1280 ℃, preserving heat for 4-6 hours, preferably 5 hours, finally cooling to room temperature at a speed of 5 ℃/min under an equilibrium condition, and introducing high-purity nitrogen in the cooling process.

The silicon element is one of the commonly used additive elements of the ferrite, and the proper silicon content has very obvious effects on improving the magnetic conductivity and the resistivity of the ferrite and reducing the high-frequency loss. However, silicon is a non-magnetic element, and the magnetic performance of the material is reduced by excessive addition. According to the pen study: the tantalum can prevent inorganic non-metal elements from entering the crystal grains by similar barrier action at the crystal grain boundaries, thereby helping the doped elements to gather at the crystal grain boundaries, and in addition, according to the research of a pen person on the tantalum-iron-silicon multilayer film, the tantalum can uniformly adsorb silicon elements in a self matrix without obvious gradient distribution. By utilizing the uniformly dispersed interaction between the tantalum and the silicon, the silicon can be uniformly deviated at the grain boundary of the ferrite, and the silicon is prevented from deviating at a high concentration to cause resistance unbalance, so that electronic transition is generated to reduce the resistivity. The uniform dispersion distribution of silicon at the grain boundary can increase the overall resistivity of the ferrite, so that the loss of the product at the frequency of MHz level is further reduced. Under the technical background of high frequency and miniaturization of the electronic components, the method has very wide application prospect.

In the invention, the main materials of the iron-passing formula can ensure higher saturation magnetic induction intensity and higher Curie temperature. The doping auxiliary materials added conventionally such as vanadium pentoxide, niobium pentoxide, bismuth oxide, cobalt oxide, molybdenum oxide, calcium carbonate and the like help the ferrite to form grains (about 10-18 mu m) with proper size and uniform size in the sintering process, discharge air holes and improve the density (about 4.8-5.0 g/cm)³) And the resistivity of the material is improved while the grain boundary is deposited.

Detailed Description

The present invention is described in detail below with reference to specific examples, but the present invention is not limited thereto in any way.

The low-loss tantalum-silicon composite manganese-zinc-doped ferrite material comprises a main material and a doping material, wherein the main material comprises ferric oxide, manganese oxide and zinc oxide, the mass ratio of the ferric oxide to the manganese oxide to the zinc oxide is (68-71) - (20-25) - (6-9), and the doping material comprises a tantalum simple substance and a silicon simple substance.

In the material, the total mass of the raw materials of the material is 100 wt%, the content of tantalum is 100-300 PPM, and the content of silicon is 100-200 PPM.

In the material, the total content of the auxiliary materials is 500-2000 PPM, wherein the total mass of the raw materials of the material is 100 wt%.

s1: adding iron oxide, manganese oxide and zinc oxide into a ball mill for ball milling, wherein the rotating speed of the ball mill is 200-250 r/min, and the ball milling time is 2-4 h, so as to obtain a mixture A;

s2: pre-burning the mixture A in an air atmosphere at the pre-burning temperature of 850-900 ℃ for 50-90 min, and then cooling to room temperature to obtain a pre-burned material B;

s3: adding the pre-sintered material B and the doping material into a ball mill for secondary ball milling, wherein the rotating speed of the ball mill is 200-250 r/min, the ball milling time is 8-10 h, and then drying is carried out, the drying temperature is 70-80 ℃, and the drying time is 20-24 h, so as to obtain a mixture C;

s4: adding a proper amount of polyvinyl alcohol solution into the mixture C, mixing, performing spray granulation, and then sieving by a 100-120-mesh sieve to obtain powder particles;

s5: putting the powder particles into an annular die, and performing compression molding by using a constant-load press, wherein the load applied by the constant-load press is 400-500 MPa, and maintaining the pressure for 340-380 seconds to obtain an annular blank;

s6: sintering the blank in a balanced atmosphere, wherein the sintering process specifically comprises the following steps: heating to 400 ℃ at the speed of 2 ℃/min under the vacuum condition, heating to 600 ℃ at the speed of 5 ℃/min, heating to 1200 ℃ at the speed of 3 ℃/min under a high-purity nitrogen atmosphere, then filling air to adjust to 5% oxygen partial pressure, heating to 1250-1315 ℃ at the speed of 1 ℃/min, preserving heat for 4-6 h, finally cooling to room temperature at the speed of 5 ℃/min under the equilibrium condition, and introducing high-purity nitrogen in the cooling process to obtain the tantalum-silicon composite doped manganese-zinc ferrite material.

Example 1

A low-loss silicon-tantalum composite manganese-zinc-doped ferrite material comprises a main material, a doping material and an auxiliary material, wherein the main material comprises ferric oxide, manganese oxide and zinc oxide, the mass ratio of the ferric oxide to the manganese oxide to the zinc oxide is 69:25:6, the doping material comprises tantalum and silicon, the silicon content is 100PPM, the tantalum content is 100PPM, the auxiliary material comprises vanadium pentoxide, niobium pentoxide, bismuth oxide, cobalt oxide and calcium carbonate, and the total content of the auxiliary material is 700 PPM. The material is prepared by the following steps:

s1: weighing 138g of iron oxide, 50g of manganese oxide and 12g of zinc oxide according to the proportion, adding the materials into a ball mill for ball milling, wherein the rotating speed of the ball mill is 200r/min, and the ball milling time is 2 hours to obtain a mixture A;

s2: pre-burning the mixture A for 55min at 860 ℃ in air atmosphere, and then cooling to room temperature to obtain a pre-burnt material B;

s3: adding the pre-sintered material B, the auxiliary material and the doping material (comprising vanadium pentoxide, niobium pentoxide, bismuth oxide, cobalt oxide, calcium carbonate, tantalum and silicon powder, wherein the addition amount is 100PPM, 150PPM, 200PPM, 100PPM and 100PPM in sequence) into a ball mill for secondary ball milling according to the proportion, wherein the rotating speed of the ball mill is 200r/min, the ball milling time is 8 hours, and drying for 24 hours at 80 ℃ to obtain a mixture C;

s4: adding a proper amount of polyvinyl alcohol solution into the mixture C, mixing, performing spray granulation, and then sieving by a 100-mesh sieve to obtain powder particles;

s5: putting the powder particles into an annular die, and performing compression molding by using a constant-load press, wherein the load applied by the constant-load press is 450MPa, and maintaining the pressure for 360 seconds to obtain a blank;

s6: sintering the blank at 1260 ℃ in a balanced atmosphere, wherein the sintering process specifically comprises the following steps: heating to 400 ℃ at a speed of 2 ℃/min under a vacuum condition, heating to 600 ℃ at a speed of 5 ℃/min, heating to 1200 ℃ at a speed of 3 ℃/min under a high-purity nitrogen atmosphere, then charging air to adjust to 5% oxygen partial pressure, heating to 1260 ℃ at a speed of 1 ℃/min, preserving heat for 5h, cooling to room temperature at a speed of 5 ℃/min under an equilibrium condition, introducing high-purity nitrogen in a cooling process, and obtaining the tantalum-silicon composite doped manganese-zinc ferrite material, namely a magnetic ring, which has crystal grains with the size of about 10-16 mu m and 4.87g/cm³The magnetic ring of the material has initial magnetic permeability of 2800 and saturation magnetic induction of 0.50T measured by a direct current soft magnetic measuring instrument, Curie temperature of 220 ℃ measured by a Curie point measuring instrument, and loss of 340kW/m measured by an alternating current soft magnetic measuring instrument under the conditions of 100 ℃, 3MHz and 10mT³Summarized in Table 1.

Example 2

The low-loss silicon-tantalum composite manganese-doped zinc ferrite material comprises a main material, a doping material and an auxiliary material, wherein the main material comprises ferric oxide, manganese oxide and zinc oxide, the mass ratio of the ferric oxide to the manganese oxide to the zinc oxide is 70:23:7, the doping material comprises tantalum and silicon, the silicon content is 120PPM, the tantalum content is 110PPM, the auxiliary material comprises vanadium pentoxide, niobium pentoxide, cobalt oxide, molybdenum oxide and calcium carbonate, and the total content of the auxiliary material is 600 PPM. The material is prepared by the following steps:

s1: weighing 140g of iron oxide, 46g of manganese oxide and 14g of zinc oxide according to the proportion, adding the iron oxide, the 46g of manganese oxide and the 14g of zinc oxide into a ball mill for ball milling, wherein the rotating speed of the ball mill is 210r/min, and the ball milling time is 2.5 hours to obtain a mixture A;

s2: pre-burning the mixture A for 55min at 870 ℃ in air atmosphere, and then cooling to room temperature to obtain a pre-burned material B;

s3: adding the pre-sintered material B, the auxiliary material and the doping material (comprising vanadium pentoxide, niobium pentoxide, cobalt oxide, molybdenum oxide, calcium carbonate, tantalum and silicon powder, wherein the adding amount is 100PPM, 150PPM, 100PPM, 110PPM and 120PPM in sequence) into a ball mill for secondary ball milling according to the proportion, wherein the rotating speed of the ball mill is 210r/min, the ball milling time is 8.5h, and drying for 24h at 80 ℃ to obtain a mixture C;

s6: sintering the blank at 1270 ℃ in a balanced atmosphere, wherein the sintering process comprises the following steps: heating to 400 ℃ at a speed of 2 ℃/min under a vacuum condition, heating to 600 ℃ at a speed of 5 ℃/min, heating to 1200 ℃ at a speed of 3 ℃/min under a high-purity nitrogen atmosphere, then charging air to adjust to 5% oxygen partial pressure, heating to 1270 ℃ at a speed of 1 ℃/min, preserving heat for 5h, cooling to room temperature at a speed of 5 ℃/min under an equilibrium condition, introducing high-purity nitrogen in a cooling process to obtain the tantalum-silicon composite manganese-zinc-doped ferrite material, namely a magnetic ring, which has crystal grains with the size of about 12-18 mu m and 4.91g/cm³The magnetic ring of the material has initial magnetic conductivity of 2950 and saturation magnetic induction of 0.51T measured by a direct-current soft magnetic measuring instrument, Curie temperature of 234 ℃ measured by a Curie point tester and loss of 332kW/m measured by an alternating-current soft magnetic measuring instrument under the conditions of 100 ℃, 3MHz and 10mT³Summarized in Table 1.

Example 3

The low-loss silicon-tantalum composite manganese-doped zinc ferrite material comprises a main material, a doping material and an auxiliary material, wherein the main material comprises iron oxide, manganese oxide and zinc oxide, the mass ratio of the iron oxide to the manganese oxide to the zinc oxide is 71:21:8, and the doping material comprises tantalum and silicon. The silicon content is 150PPM, the tantalum content is 150PPM, the auxiliary materials comprise vanadium pentoxide, niobium pentoxide, bismuth oxide, cobalt oxide, molybdenum oxide and calcium carbonate, and the content of the auxiliary materials is 800 PPM. The material is prepared by the following steps:

s1: weighing 142g of iron oxide, 42g of manganese oxide and 16g of zinc oxide according to the proportion, adding the materials into a ball mill for ball milling, wherein the rotating speed of the ball mill is 220r/min, and the ball milling time is 3 hours to obtain a mixture A;

s2: pre-burning the mixture A for 60min at 870 ℃ in air atmosphere, and then cooling to room temperature to obtain a pre-burned material B;

s3: adding the pre-sintered material B, the auxiliary material and the doping material (comprising vanadium pentoxide, niobium pentoxide, bismuth oxide, cobalt oxide, molybdenum oxide, calcium carbonate, tantalum and silicon powder in the addition amount of 150PPM, 100PPM, 150PPM and 150PPM in sequence) into a ball mill for secondary ball milling according to the proportion, wherein the rotating speed of the ball mill is 220r/min, the ball milling time is 9h, and drying is carried out for 24h at 80 ℃ to obtain a mixture C;

s6: sintering the blank at 1275 ℃ in a balanced atmosphere, wherein the sintering process comprises the following steps: heating to 400 ℃ at a speed of 2 ℃/min under a vacuum condition, heating to 600 ℃ at a speed of 5 ℃/min, heating to 1200 ℃ at a speed of 3 ℃/min under a high-purity nitrogen atmosphere, then charging air to adjust to 5% oxygen partial pressure, heating to 1275 ℃ at a speed of 1 ℃/min, preserving heat for 5h, cooling to room temperature at a speed of 5 ℃/min under an equilibrium condition, introducing high-purity nitrogen in a cooling process to obtain the tantalum-silicon composite manganese-zinc-doped ferrite material, namely a magnetic ring, which has crystal grains with the size of about 14-18 mu m and 4.95g/cm³The density of the magnetic ring is 3100, the saturation induction is 0.52T, the Curie point is 245 ℃, and the loss is 324kW/m under the conditions of 100 ℃, 3MHz and 10mT by using a direct-current soft magnetic measuring instrument³Summarized in Table 1.

Example 4

The low-loss silicon-tantalum composite manganese-doped zinc ferrite material comprises a main material, a doping material and an auxiliary material, wherein the main material comprises iron oxide, manganese oxide and zinc oxide, the mass ratio of the iron oxide to the manganese oxide to the zinc oxide is 71:20:9, and the doping material comprises tantalum and silicon. The silicon content is 180PPM, the tantalum content is 200PPM, the auxiliary materials comprise vanadium pentoxide, niobium pentoxide, bismuth oxide, cobalt oxide, molybdenum oxide and calcium carbonate, and the content of the auxiliary materials is 750 PPM. The material is prepared by the following steps:

s1: weighing 142g of iron oxide, 40g of manganese oxide and 18g of zinc oxide according to the proportion, adding the materials into a ball mill for ball milling, wherein the rotating speed of the ball mill is 230r/min, and the ball milling time is 4 hours to obtain a mixture A;

s2: pre-burning the mixture A at 880 ℃ for 60min in an air atmosphere, and then cooling to room temperature to obtain a pre-burned material B;

s3: adding the pre-sintered material B, the auxiliary material and the doping material (comprising vanadium pentoxide, niobium pentoxide, bismuth oxide, cobalt oxide, molybdenum oxide, calcium carbonate, tantalum and silicon powder in the addition amount of 150PPM, 100PPM, 150PPM, 200PPM and 180PPM in sequence) into a ball mill for secondary ball milling according to the proportion, wherein the rotating speed of the ball mill is 230r/min, the ball milling time is 10h, and drying for 24h at 80 ℃ to obtain a mixture C;

s6: sintering the blank at 1280 ℃ in a balanced atmosphere, wherein the sintering process specifically comprises the following steps: heating to 400 ℃ at a speed of 2 ℃/min under a vacuum condition, heating to 600 ℃ at a speed of 5 ℃/min, heating to 1200 ℃ at a speed of 3 ℃/min under a high-purity nitrogen atmosphere, then charging air to adjust to 5% oxygen partial pressure, heating to 1280 ℃ at a speed of 1 ℃/min, preserving heat for 5 hours, finally cooling to room temperature at a speed of 5 ℃/min under an equilibrium condition, introducing high-purity nitrogen in a cooling process, and obtaining the tantalum-silicon composite manganese-zinc-doped ferrite material, namely a magnetic ring, which has crystal grains with the size of about 16-20 mu m and 4.95g/cm³Of the material measured by a direct current soft magnetic measuring instrumentThe initial magnetic conductivity of the magnetic ring is 3450, the saturation magnetic induction is 0.53T, the Curie temperature measured by a Curie point tester is 260 ℃, and the loss measured by an AC soft magnetic measuring instrument under the conditions of 100 ℃, 3MHz and 10mT is 305kW/m³Summarized in Table 1.

Comparative example 1

The manganese-zinc ferrite material comprises a main material and an auxiliary material, wherein the main material comprises ferric oxide, manganese oxide and zinc oxide, the mass ratio of the ferric oxide to the manganese oxide to the zinc oxide is 71:20:9, the auxiliary material comprises vanadium pentoxide, niobium pentoxide, bismuth oxide, cobalt oxide, molybdenum oxide and calcium carbonate, and the content of the auxiliary material is 750 PPM. The material is prepared by the following steps:

s3: adding the pre-sintered material B and auxiliary materials (comprising vanadium pentoxide, niobium pentoxide, bismuth oxide, cobalt oxide, molybdenum oxide and calcium carbonate, wherein the addition amount is 150PPM, 100PPM and 150PPM in sequence) into a ball mill for secondary ball milling according to the proportion, wherein the rotating speed of the ball mill is 230r/min, the ball milling time is 10 hours, and drying for 24 hours at 80 ℃ to obtain a mixture C;

s6: sintering the blank at 1280 ℃ in a balanced atmosphere, wherein the sintering process specifically comprises the following steps: heating to 400 deg.C at 2 deg.C/min under vacuum, heating to 600 deg.C at 5 deg.C/min, heating to 1200 deg.C at 3 deg.C/min under high-purity nitrogen atmosphere, introducing air to adjust to 5% oxygen partial pressure,heating to 1280 ℃ at the speed of 1 ℃/min, preserving heat for 5h, finally cooling to room temperature at the speed of 5 ℃/min under the equilibrium condition, introducing high-purity nitrogen in the cooling process to obtain the manganese-zinc ferrite material, wherein the manganese-zinc ferrite material has crystal grains with the size of about 14-19 mu m and 4.91g/cm³The density of the material is 3200 magnetic ring initial permeability measured by a direct current soft magnetic measuring instrument, 0.51T saturated magnetic induction intensity, 255 ℃ Curie temperature, and 350kW/m loss measured by an alternating current soft magnetic measuring instrument under the conditions of 100 ℃, 3MHz and 10mT³Summarized in Table 1.

TABLE 1

Comparing example 1, example 2, example 3, example 4 and comparative example 1, one can obtain: the tantalum-silicon doped manganese-zinc ferrite material added with the simple substance tantalum and the simple substance silicon has the characteristics of high frequency and low loss, and the loss is 305-340 kW/m under the conditions of 100 ℃, 3MHz and 10mT³Is far lower than that of manganese-zinc ferrite material (350 kW/m) without adding elementary substance tantalum³)。

Comparing example 1, example 2, example 3 and example 4, one can obtain: when the mass ratio of the iron oxide to the manganese oxide to the zinc oxide is (70-71): (21-22): 7-8), the doping materials comprise vanadium pentoxide, niobium pentoxide, bismuth oxide, cobalt oxide, molybdenum oxide, calcium carbonate, tantalum and silicon, the content of the tantalum is 100-200 PPM, and the content of the silicon is 100-180 PPM, the tantalum-silicon composite manganese-zinc doped ferrite material has the characteristic of low loss.

The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.

Claims

1. a low-loss tantalum-silicon compound doped manganese-zinc ferrite material, is characterized in that, comprises main material and doping material, and described main material comprises iron oxide, manganese oxide and zinc oxide, and described iron oxide The mass ratio of manganese oxide and zinc oxide is (68-71):(20-25):(6-9), and the dopant includes tantalum and silicon.

2 . The low-loss tantalum-silicon compound doped manganese-zinc ferrite material according to claim 1 , wherein, in the material, the total mass of the raw material is 100 wt %, and the tantalum element The content is 100-300PPM, and the content of silicon element is 100-200PPM.

3. The low-loss tantalum-silicon composite doped manganese-zinc ferrite material according to claim 1, wherein the material further comprises an auxiliary material, and the auxiliary material comprises vanadium pentoxide, five One or more of niobium oxide, bismuth oxide, cobalt oxide, molybdenum oxide or calcium carbonate are mixed.

4. The low-loss tantalum-silicon composite doped manganese-zinc ferrite material according to claim 3, wherein in the material, the total mass of the material raw material is 100wt%, the amount of the auxiliary material is The total content is 500～2000PPM.

5. A preparation method of the tantalum-silicon composite doped manganese-zinc ferrite material according to any one of claims 1-4, wherein the preparation method specifically comprises the following steps:

S1: adding iron oxide, manganese oxide and zinc oxide into a ball mill for ball milling to obtain mixture A;

S2: pre-sintering mixture A, and then cooling to room temperature to obtain pre-sintering material B;

S3: adding the pre-sintered material B and the doping material to the ball mill for secondary ball milling, and then drying to obtain the mixture C;

S4: add polyvinyl alcohol solution to mixing material C and mix to carry out spray granulation, then sieve to obtain powder particles;

S5: put the powder particles into the mold, and carry out compression molding to obtain a blank;

S6: sintering the blank in a balanced atmosphere to obtain the tantalum-silicon composite doped manganese-zinc ferrite material.

6 . The method for preparing a tantalum-silicon composite doped manganese-zinc ferrite material according to claim 5 , wherein, in step S1 , the rotating speed of the ball mill is 200～250r/min, and the ball milling time is 2～250 r/min. 7 . 4h.

7 . The method for preparing a tantalum-silicon compound doped manganese-zinc ferrite material according to claim 5 , wherein in step S2 , pre-sintering is carried out in an air atmosphere, and the pre-sintering temperature is 850-900 ℃. 8 . ℃, the burn-in time is 50-90min;

In step S3, the rotational speed of the ball mill is 200-250 r/min, the ball-milling time is 8-10 h, the drying temperature is 70-80° C., and the drying time is 20-24 h.

8 . The method for preparing a tantalum-silicon composite doped manganese-zinc ferrite material according to claim 5 , wherein in step S4 , after granulation, a 100-120 mesh sieve is passed. 9 .

9 . The method for preparing a tantalum-silicon composite doped manganese-zinc ferrite material according to claim 5 , wherein in step S5 , a constant-load press is used to carry out compression molding, and the constant-load press applies the The load is 400 ~ 500MPa, and the pressure is maintained for 340 ~ 380s.

10 . The method for preparing a tantalum-silicon composite doped manganese-zinc ferrite material according to claim 5 , wherein, in step S6 , the sintering process is specifically: first under vacuum conditions at 2° C./min. 11 . The temperature was raised to 400°C at a rate of 5°C/min, then heated to 600°C at a rate of 5°C/min, and then heated to 1200°C at a rate of 3°C/min under a high-purity nitrogen atmosphere, and then filled with air to adjust to 5% oxygen partial pressure , heated to 1250-1315°C at a rate of 1°C/min, kept for 4-6 hours, and finally cooled to room temperature at a rate of 5°C/min under equilibrium conditions, and passed high-purity nitrogen during the cooling process.