Method for producing a soft magnetic manganese-zinc ferrite with a wide temperature range and high magnetic permeability for automotive electronics

Abstract

A method for producing a soft magnetic manganese-zinc ferrite with a wide temperature range and high magnetic permeability for automotive electronics, characterized in that the material comprises main components and auxiliary components, wherein the main components comprise Fe₂O₃: 53 mol% to 55 mol%, ZnO: 16 mol% to 19 mol%, the remainder being Mn₃O₄, wherein, based on the total weight of the main components, the auxiliary components comprise nano-CaCO₃: 400 ppm to 1000 ppm, nano-TiO₂: 2000 to 6000 ppm, nano-Co₂O₃: 500 ppm to 2000 ppm, nano-Nb₂O₅: 100 ppm to 350 ppm, nano-SiO₂: 20 ppm to 150 ppm, nano-CuO: 0 ppm to 600 ppm, wherein the method for production comprises the following steps: Step 1, Preparation: the main components Fe2O3, ZnO and Mn3O4 are weighed according to their proportions and mixed by wet ball milling, with a mixing time of 10 to 40 minutes; Step 2, Pre-firing: the mixture obtained from step 1 is dried and pre-fired at 700 °C to 1000 °C, holding the temperature for 1 to 3 hours; Step 3, Grinding: the pre-burned material obtained from step 2 is shaken and the auxiliary components Nano-CaCO3, Nano-TiO2, Nano-Co2O3, Nano-Nb2O5, Nano-SiO2 and Nano-CuO are added according to the proportions, using the fluidized bed airflow milling method to grind the pre-burned material; Step 4, Granulation: the powder is granulated after airflow milling; Step 5, Pressing and Forming: it is pressed into a ring-shaped base body with the dimensions Ø 25mm in diameter * Ø 15mm in diameter * 7.5mm, with a density of 3.15g / cm³. 3 up to 3.35g / cm³ 3 amounts; Step 6, sintering, where the sintering temperature is 1200 to 1280°C, the holding time is 4 to 8 hours and the equilibrium oxygen content is 3.0 to 8.0%.

Description

Technical field

[0001] The invention relates to a soft magnetic manganese-zinc ferrite with a wide temperature range and high magnetic permeability for automotive electronics as well as a manufacturing process and belongs to the technical field of magnetic materials. State of the art

[0002] My country's automotive electronics market continues to grow rapidly and has become a key driver for the development of vehicle electrification, intelligence, and connectivity. Fueled by artificial intelligence, cloud computing, autonomous driving, 5G, and other technologies, and guided by the development strategy for new energy vehicles, my country's automotive electronics sector has entered a new phase of technological iteration and industrial modernization. The cost share of automotive electronics in complete vehicles continues to increase, and automotive-grade chips and sensors are expected to become the central driving force for industrial development, marking another golden age for automotive electronics in my country.

[0003] The operating environment for automotive electronics products is very harsh, and temperature has a significant impact on electronic products. The car engine itself is a heat source. If the vehicle is running at full load in hot climates and the engine is immediately stopped and switched off, the heat emitted from the exhaust pipe causes the temperature in the engine compartment to rise above 100°C. In cold climates, prolonged parking of a vehicle outdoors can cause the temperature in the engine compartment to drop below -40°C. Therefore, automotive electronics products, which are generally installed in the engine compartment, must function normally within a temperature range of -40°C to +125°C; otherwise, they will impair the vehicle's drivability and even cause safety problems.

[0004] This necessitates excellent temperature stability of components in automotive electronics products across a temperature range of -40°C to +125°C. However, existing materials with high magnetic permeability often exhibit excessive changes in magnetic permeability at excessively high or low temperatures. At such extreme temperatures, proper functioning of automotive electronics products is challenging. Research indicates that sensible formulation and preparation process research can improve the material's temperature properties, which is of significant importance for the production of soft magnetic manganese-zinc ferrite with a wide temperature range and high magnetic permeability for automotive electronics.

[0005] Publication number CN 1 01 620 908 A discloses a low-loss manganese-zinc ferrite material with a wide temperature range, a wide frequency range, and a high Curie point, as well as its manufacturing process. Compared to this patent, the present invention adopts the process of airflow milling and low-temperature sintering, and the magnetic conductivity of the material is higher, and the temperature stability of the magnetic permeability in the range of -40 to +125 °C is improved. Publication number CN 1 12 194 480 A discloses a manganese-zinc ferrite material with a wide temperature range, a high Bs value, and a low temperature coefficient, as well as its manufacturing process, wherein the formula and doping system used in this patent differ from that of this material.Its initial magnetic permeability is in the range of 2500 to 3300, which is significantly lower than the magnetic permeability performance of the material of the present invention. The present invention employs airflow milling and low-temperature sintering, resulting in a material with higher magnetic permeability and improved temperature stability. Publication number CN 1 03 896 567 A discloses a manufacturing technology for ferrite materials with a low temperature coefficient, the manufacturing process of which differs considerably from that of the present invention. Its operating temperature range is only in the range of -10 °C to 55 °C, and its specific temperature coefficient is much lower than that of the material of the present invention.Patent number CN 1 06 747 396 B discloses a manganese-zinc ferrite material with high magnetic permeability for automotive electronics and its manufacturing process. It differs significantly from the doping system and process of the material of the present invention, in that it does not use Co₂O₃ and TiO₂, nor does it employ the airflow milling process, and it exhibits good temperature stability only from 25°C to 80°C. Publication number CN 1 09 626 981 A discloses a manganese-zinc ferrite with a wide temperature range, a wide frequency range, and high magnetic permeability, and its manufacturing process; however, its operating temperature range is limited to 2°C to 110°C, and it lacks a magnetic permeability characteristic in the negative temperature range.

[0006] DE 11 2021 005 797 T5 relates to a manganese-zinc ferrite material with high magnetic permeability, high frequency, high impedance and high Curie temperature.

[0007] In summary, current technology lacks a soft magnetic manganese-zinc ferrite material with properties such as a wide temperature range and high magnetic permeability in the range of -40 °C to +125 °C, which can be used in automotive electronics products and is suitable for normal operation under extreme temperature conditions. The material according to the invention exhibits high magnetic permeability and temperature stability, an excellent specific temperature coefficient, a low specific loss factor, a high Curie temperature, and a high Bs value in the range of -40 °C to +125 °C and can fully meet the application requirements for materials in automotive electronics. Content of the invention

[0008] To solve the aforementioned problems, the present invention provides a method for producing a soft magnetic manganese-zinc ferrite with a wide temperature range and high magnetic permeability for automotive electronics. Following a thorough investigation of the magnetic material formula (in particular the formula of the auxiliary components) and the manufacturing process (in particular the airflow milling and the sintering process), and after adjusting the formula content and process parameters without apparent regularity, the present invention presents a method for producing a soft magnetic manganese-zinc ferrite with a wide temperature range and high magnetic permeability for automotive electronics.

[0009] The present invention relates to a method for producing a soft magnetic manganese-zinc ferrite with a wide temperature range and high magnetic permeability for automotive electronics.

[0010] The present invention is characterized in that the material comprises main components and auxiliary components, wherein the main components comprise Fe₂O₃: 53 mol% to 55 mol%, ZnO: 16 mol% to 19 mol%, the remainder being Mn₃O₄, wherein, based on the total weight of the main components, the auxiliary components comprise nano-CaCO₃: 400 ppm to 1000 ppm, nano-TiO₂: 4000 to 6000 ppm, nano-Co₂O₃: 500 ppm to 2000 ppm, nano-Nb₂O₅: 100 ppm to 350 ppm, nano-SiO₂: 20 ppm to 150 ppm, nano-CuO: 0 ppm to 600 ppm. The aforementioned process for producing the soft magnetic manganese-zinc ferrite with a wide temperature range and high magnetic permeability for automotive electronics comprises the following steps: Step 1, Preparation: Fe2O3: 53 mol% to 55 mol%, ZnO: 16 mol% to 19 mol%, the remainder is Mn3O4, and subsequent mixing by wet ball mills, with a mixing time of 10 minutes to 40 minutes; Step 2, Pre-burning: the mixture obtained from step 1 is dried and then pre-burned, with a pre-burning temperature of 700°C to 1000°C, a temperature rise rate of 3°C / min to 5°C / min, and the temperature held for 1 hour to 3 hours; Step 3, Grinding: the pre-burned material obtained from step 2 is shaken and then the auxiliary components are added: Nano-CaCO3: 400 ppm to 1000 ppm, Nano-TiO2: 2000 ppm to 6000 ppm, Nano-Nb2O5: 100 ppm to 350 ppm, Nano-SiO2: 20 ppm to 150 ppm, Nano-CuO: 0 ppm to 600 ppm. In fluidized bed airflow milling, the air pressure is 0.6 MPa to 1.0 MPa, the speed of the classifying wheel is 8000 rpm, the airflow milling time is 30 to 60 minutes, and the D50 particle size range after comminution is 1.0 µm to 1.3 µm, and the D90 particle size range is 2.1 µm to 2.6 µm; Step 4, Granulation: for the powder after airflow milling, 3 wt.% to 20 wt.% polyvinyl alcohol is added according to the total weight of the powder, milled and sieved into particles of a specific size; Step 5, Pressing and Forming: it is pressed into a ring-shaped base body with the dimensions Ø 25mm in diameter * Ø 15mm in diameter * 7.5mm, with a density of 3.15g / cm³. 3 up to 3.35g / cm² 3 is; Step 6, Sintering: the sintering temperature is 1200°C to 1280°C, the holding time is 4 to 8 hours and the equilibrium oxygen content is 3.0% to 8.0%, and after sintering the grain size is refined to 15 µm to 20 µm.

[0011] As a preferred solution, the main components of a soft magnetic manganese-zinc ferrite with a wide temperature range and high magnetic permeability for automotive electronics are Fe2O3: 53.0 mol% to 54.0 mol%, ZnO: 16.0 mol% to 17.5 mol%, the remainder is Mn3O4, where, based on the total weight of the main components, the auxiliary components are Nano-CaCO3: 400 ppm to 800 ppm, Nano-TiO2: 4000 to 6000 ppm, Nano-Co2O3: 500 ppm to 2000 ppm, Nano-Nb2O5: 100 ppm to 300 ppm, Nano-SiO2: 20 ppm to 100 ppm, Nano-CuO: 0 ppm to 600 ppm.

[0012] As a preferred solution in step 6, the sintering temperature is 1200 to 1240°C, the holding time is 4 to 8 hours and the equilibrium oxygen content is 3.0 to 8.0%.

[0013] The combined effect of TiO2 and Co2O3 controls the magnetocrystalline anisotropy constant K1 of the material, resulting in minimal change in the magnetic permeability of the soft magnetic ferrite across a wide temperature range and good stability, thus optimizing the material's overall µ-T curve. Since the doping of TiO2 and Co2O3 is highly temperature-dependent, doping with Nb2O5 and SiO2 lowers the sintering temperature to prevent degradation of the material properties at high sintering temperatures. Simultaneously, this refines the crystal grain size, giving the soft magnetic ferrite good grain consistency, thereby reducing stresses and minimizing changes in magnetic permeability at different temperatures.

[0014] In step 3, a fluidized bed airflow mill is used to grind the particles, with compressed air serving as the working medium. Upon entering the airflow mill, the particles primarily collide with other particles, causing fragmentation. As the feed begins, the particles gradually accumulate in the airflow mill while being continuously ground. The smaller particles are then classified into products by the classifying wheel. Its grinding principle is based mainly on impact and collision.Compared to conventional ball milling, this airflow milling method yields powders with a smaller particle size and more uniform distribution, effectively reducing D50 to D90. Furthermore, it eliminates unnecessary impurities during the milling process, resulting in a higher purity of the final product. This is because, unlike conventional ball milling, it utilizes the airflow to create self-shredding between the particles. Conventional ball milling uses spherical materials that collide with particles through friction, causing these materials to wear down during the friction process and generate unnecessary impurities, leading to the presence of contaminants in the milled final product.Reducing the particle size from D50 to D90 can increase the powder's activity, and in conjunction with low-temperature sintering conditions, grain growth can become more uniform, resulting in ferrite materials with high magnetic permeability and improved temperature stability. Simultaneously, reducing the amount of introduced impurities can prevent unwanted effects and abnormal grain growth.

[0015] Compared to the prior art, the present invention has the following advantageous effects: The inventive soft magnetic manganese-zinc ferrite with a wide temperature range and high magnetic permeability for automotive electronics exhibits excellent µ-T properties from -40 °C to +125 °C, and the magnetic permeability is stable above 5000. The temperature stability of the magnetic permeability is high, and the technical performance, indicators, and parameters are as follows: (1) Initial magnetic permeability µi≥5000 (T=25°C, B<0.25mT, 10kHz); (2) Specific loss factor tanδ / µ i <3 (T=25°C, B<0.25mT, 100kHz); (3) Relative temperature factor α F : (-0.5-0.5) ×10 -6 (f=10kHz, B<0.25mT, -40 to +125°C);7 (4) Intensity of magnetic saturation induction B S ≥460mT (25°C, H=1194A / m); (5) Curie temperature Tc ≥180°C.

[0016] The high magnetic permeability of the inventive soft magnetic manganese-zinc ferrite with a wide temperature range and high magnetic permeability for automotive electronics can meet the requirements of device filtration and miniaturization, while excellent temperature stability ensures that elements function normally under extreme temperature conditions, thereby guaranteeing the safety and stability of automotive electronic products. Description of the characters Fig. 1 is a difference diagram of α F (-40°C to +125°C) between exemplary embodiments and comparative examples; Fig. Figure 2 is a graph showing the change in magnetic permeability of soft magnetic manganese zinc ferrite as a function of temperature in the embodiments and comparative examples. Specific embodiments

[0017] The soft magnetic manganese-zinc ferrite with a wide temperature range and high magnetic permeability for automotive electronics produced by the present invention, and the manufacturing process, are described clearly and completely below with reference to specific implementation examples. Obviously, the described embodiments are only some of the embodiments of the present invention, not all embodiments. All other embodiments that a person skilled in the art in this field would derive from the embodiments in the present invention without any creative effort are within the scope of protection of the present invention. Exemplary embodiment 1: A method for producing a soft magnetic manganese-zinc ferrite material with a wide temperature range and high magnetic permeability for automotive electronics, comprising main components and auxiliary components, wherein the manufacturing process is as follows: Step 1, Preparation: Fe2O3: 53.1 mol%, ZnO: 17 mol%, and the remainder is Mn3O4 ingredients, and subsequent mixing by wet ball mills, with a mixing time of 20 minutes; Step 2, Pre-burning: the mixture obtained from step 1 is dried and then pre-burned, with a pre-burning temperature of 900 °C, a temperature rise rate of 5 °C / min, and the temperature held for 2 hours; Step 3, Grinding: the obtained pre-burned material is shaken and then the auxiliary components are added: Nano-CaCO3: 500 ppm, Nano-TiO2: 4000 ppm, Co2O3: 1000 ppm, Nano-Nb2O5: 200 ppm, Nano-SiO2: 60 ppm, Nano-CuO: 200 ppm, with grinding carried out for 50 minutes using fluidized bed airflow; Step 4, Granulation: depending on the total weight of the powder obtained after airflow milling, 15 wt% polyvinyl alcohol is added, milled and sieved into particles of a specific size; Step 5, Pressing and Forming: it is pressed into a ring-shaped base body with the dimensions Ø 25mm in diameter * Ø 15mm in diameter * 7.5mm, with a density of 3.2 g / cm³. 3 is; Step 6, Sintering: the sintering temperature is 1220 °C, the equilibrium oxygen content is 4% and the temperature is held for 5 hours. Exemplary embodiment 2: A method for producing a soft magnetic manganese-zinc ferrite material with a wide temperature range and high magnetic permeability for automotive electronics, comprising main components and auxiliary components, wherein the manufacturing process is as follows: Step 1, Preparation: Fe2O3: 53.1 mol%, ZnO: 17 mol%, and the remainder is Mn3O4 ingredients, and subsequent mixing by wet ball mills, with a mixing time of 20 minutes; Step 2, Pre-burning: the mixture obtained from step 1 is dried and then pre-burned, with a pre-burning temperature of 950°C, a temperature rise rate of 5°C / min, and the temperature held for 2 hours; Step 3, Grinding: the obtained pre-burned material is shaken and then the auxiliary components are added: Nano-CaCO3: 500 ppm, Nano-TiO2: 4000 ppm, Co2O3: 1000 ppm, Nano-Nb2O5: 200 ppm, Nano-SiO2: 60 ppm, Nano-CuO: 100 ppm, with grinding carried out for 50 minutes using fluidized bed airflow; Step 4, Granulation: depending on the total weight of the powder obtained after airflow milling, 15 wt% polyvinyl alcohol is added, milled and sieved into particles of a specific size; Step 5, Pressing and Forming: it is pressed into a ring-shaped base body with the dimensions Ø 25mm in diameter * Ø 15mm in diameter * 7.5mm, with a density of 3.2 g / cm³. 3 is; Step 6, Sintering: the sintering temperature is 1240°C, the equilibrium oxygen content is 4% and the temperature is held for 5 hours. Exemplary embodiment 3: A method for producing a soft magnetic manganese-zinc ferrite material with a wide temperature range and high magnetic permeability for automotive electronics, comprising main components and auxiliary components, wherein the manufacturing process is as follows: Step 1, Preparation: Fe2O3: 53.3 mol%, ZnO: 16.9 mol%, and the remainder is Mn3O4 ingredients, and subsequent mixing by wet ball mills, with a mixing time of 20 minutes; Step 2, Pre-burning: the mixture obtained from step 1 is dried and then pre-burned, with a pre-burning temperature of 900 °C, a temperature rise rate of 5 °C / min, and the temperature held for 2 hours; Step 3, Grinding: the obtained pre-burned material is shaken and then the auxiliary components are added: Nano-CaCO3: 500 ppm, Nano-TiO2: 4800 ppm, Co2O3: 1200 ppm, Nano-Nb2O5: 200 ppm, Nano-SiO2: 20 ppm, Nano-CuO: 200 ppm, with grinding carried out for 50 minutes with fluidized bed airflow; Step 4, Granulation: depending on the total weight of the powder obtained after airflow milling, 15 wt% polyvinyl alcohol is added, milled and sieved into particles of a specific size; Step 5, Pressing and Forming: it is pressed into a ring-shaped base body with the dimensions Ø 25mm in diameter * Ø 15mm in diameter * 7.5mm, with a density of 3.2 g / cm³. 3 is; Step 6, Sintering: the sintering temperature is 1240°C, the equilibrium oxygen content is 4% and the temperature is held for 5 hours. Comparative example 1: A method for producing a soft magnetic manganese-zinc ferrite material with a wide temperature range and high magnetic permeability for automotive electronics, consisting of main components and auxiliary components, wherein the manufacturing process is as follows: Step 1, Preparation: Fe2O3: 53.1 mol%, ZnO: 17 mol%, and the remainder is Mn3O4 ingredients, and subsequent mixing by wet ball mills, with a mixing time of 20 minutes; Step 2, Pre-burning: the mixture obtained from step 1 is dried and then pre-burned, with a pre-burning temperature of 900 °C, a temperature rise rate of 5 °C / min, and the temperature held for 2 hours; Step 3: Grinding, the resulting pre-burned material is shaken and then the auxiliary components are added: Nano-CaCO3: 500 ppm, Nano-TiO2: 4000 ppm, Co2O3: 1000 ppm, Nano-Nb2O5: 200 ppm, Nano-SiO2: 60 ppm, Nano-CuO: 200 ppm, with grinding in a ball mill for 80 minutes; Step 4, Granulation: depending on the total weight of the powder obtained after ball milling, 15 wt% polyvinyl alcohol is added, ground and sieved into particles of a specific size; Step 5, Pressing and Forming: it is pressed into a ring-shaped base body with the dimensions Ø 25mm in diameter * Ø 15mm in diameter * 7.5mm, with a density of 3.2 g / cm³. 3 is; Step 6, Sintering: the sintering temperature is 1220 °C, the equilibrium oxygen content is 4% and the temperature is held for 5 hours. Comparative example 2: A method for producing a soft magnetic manganese-zinc ferrite material with a wide temperature range and high magnetic permeability for automotive electronics, consisting of main components and auxiliary components, wherein the manufacturing process is as follows: Step 1, Preparation: Fe2O3: 53.2 mol%, ZnO: 16.6 mol%, and the remainder is Mn3O4 ingredients, and subsequent mixing by wet ball mills, with a mixing time of 20 minutes; Step 2, Pre-burning: the mixture obtained from step 1 is dried and then pre-burned, with a pre-burning temperature of 900 °C, a temperature rise rate of 5 °C / min, and the temperature held for 2 hours; Step 3, Grinding: the obtained pre-burned material is shaken and then the auxiliary components are added: Nano-CaCO3: 500 ppm, Nano-TiO2: 4800 ppm, Co2O3: 1200 ppm, Nano-Nb2O5: 200 ppm, Nano-SiO2: 20 ppm, Nano-CuO: 200 ppm, with grinding carried out for 50 minutes with fluidized bed airflow; Step 4, Granulation: depending on the total weight of the powder obtained after airflow milling, 15 wt% polyvinyl alcohol is added, milled and sieved into particles of a specific size; Step 5, Pressing and Forming: it is pressed into a ring-shaped base body with the dimensions Ø 25mm in diameter * Ø 15mm in diameter * 7.5mm, with a density of 3.2 g / cm³. 3 is; Step 6, Sintering: the sintering temperature is 1300°C, the equilibrium oxygen content is 4% and the temperature is held for 5 hours. Comparative example 3: A method for producing a soft magnetic manganese-zinc ferrite material with a wide temperature range and high magnetic permeability for automotive electronics, consisting of main components and auxiliary components, wherein the manufacturing process is as follows: Step 1, Preparation: Fe2O3: 53.1 mol%, ZnO: 17 mol%, and the remainder is Mn3O4 ingredients, and subsequent mixing by wet ball mills, with a mixing time of 20 minutes; Step 2, Pre-burning: the mixture obtained from step 1 is dried and then pre-burned, with a pre-burning temperature of 900 °C, a temperature rise rate of 5 °C / min, and the temperature held for 2 hours; Step 3, Grinding: the obtained pre-burned material is shaken and then the auxiliary components are added: Nano-CaCO3: 500 ppm, Nano-TiO2: 4800 ppm, Co2O3: 1200 ppm, Nano-Nb2O5: 200 ppm, Nano-SiO2: 20 ppm, Nano-CuO: 200 ppm, with grinding carried out for 20 minutes with fluidized bed airflow; Step 4, Granulation: depending on the total weight of the powder obtained after airflow milling, 15 wt% polyvinyl alcohol is added, milled and sieved into particles of a specific size; Step 5, Pressing and Forming: it is pressed into a ring-shaped base body with the dimensions Ø 25mm in diameter * Ø 15mm in diameter * 7.5mm, with a density of 3.2 g / cm³. 3 is; Step 6, Sintering: the sintering temperature is 1300°C, the equilibrium oxygen content is 4% and the temperature is held for 5 hours. Comparative example 4: A method for producing a soft magnetic manganese-zinc ferrite material with a wide temperature range and high magnetic permeability for automotive electronics, consisting of main components and auxiliary components, wherein the manufacturing process is as follows: Step 1, Preparation: Fe2O3: 53.6 mol%, ZnO: 16.7 mol%, and the remainder is Mn3O4 ingredients, and subsequent mixing by wet ball mills, with a mixing time of 20 minutes; Step 2, Pre-burning: the mixture obtained from step 1 is dried and then pre-burned, with a pre-burning temperature of 900 °C, a temperature rise rate of 5 °C / min, and the temperature held for 2 hours; Step 3, Grinding: the obtained pre-burned material is shaken and then the auxiliary components are added: Nano-CaCO3: 500 ppm, Nano-TiO2: 6000 ppm, Co2O3: 800 ppm, Nano-Nb2O5: 200 ppm, Nano-SiO2: 40 ppm, Nano-CuO: 200 ppm, with grinding carried out for 50 minutes with fluidized bed airflow; Step 4, Granulation: depending on the total weight of the powder obtained after airflow milling, 15 wt% polyvinyl alcohol is added, milled and sieved into particles of a specific size; Step 5, Pressing and Forming: it is pressed into a ring-shaped base body with the dimensions Ø 25mm in diameter * Ø 15mm in diameter * 7.5mm, with a density of 3.2 g / cm³. 3 is; Step 6, Sintering: the sintering temperature is 1220 °C, the equilibrium oxygen content is 4% and the temperature is held for 5 hours.

[0018] The results of the temperature-magnetic permeability test of the exemplary embodiments and comparative examples are as follows: Serial number initial magnetic permeability (unit) α F (×10 -6 ) -40°C 20°C 20°C +125°C (-40 to +125) °C Example 1 4882 5265 5964 0,28 Example 2 5390 5203 5242 -0,03 Example 3 4757 5434 5540 0,21 Comparative example 1 5037 4524 5548 0,12 Comparative example 2 3776 5581 5731 0,83 Comparative example 3 2626 5719 4814 1,92 Comparative example 4 4870 4538 4993 0,03

[0019] By comparing the exemplary embodiments and comparative examples, it is shown that the magnetic permeability and temperature properties of the material could be significantly improved through the use of suitable main and auxiliary components and the optimization of the material processing, in particular through the use of airflow milling and low-temperature sintering processes. From the table above and the Fig. 1 and Fig.As can be seen in Figure 2, the embodiments exhibit high magnetic permeability and good temperature stability, whereas Comparative Example 2 and Comparative Example 3 show poor stability of the initial magnetic permeability in the temperature range from -40 °C to +125 °C, with a large temperature coefficient deviation in the comparative examples. Although the magnetic permeability of Comparative Example 1 and Comparative Example 4 exhibits good temperature stability, the magnetic permeability is low. The initial magnetic permeability of the embodiments is stable above 5000, the temperature stability is high, and the temperature coefficient is tightly controlled; at the same time, the magnetic permeability changes very little between -40 °C and +125 °C.

[0020] The foregoing are only some embodiments of the present invention; however, the scope of protection of the present invention is not limited thereto.

Claims

[1] Method for producing a soft magnetic manganese-zinc ferrite with a wide temperature range and high magnetic permeability for automotive electronics, characterized by , that the material comprises main components and auxiliary components, wherein the main components are Fe2O3: 53 mol% to 55 mol%, ZnO: 16 mol% to 19 mol%, the remainder being Mn3O4, wherein, based on the total weight of the main components, the auxiliary components are Nano-CaCO3: 400 ppm to 1000 ppm, Nano-TiO2: 2000 to 6000 ppm, Nano-Co2O3: 500 ppm to 2000 ppm, Nano-Nb2O5: 100 ppm to 350 ppm, Nano-SiO2: 20 ppm to 150 ppm, Nano-CuO: 0 ppm to 600 ppm, wherein the manufacturing process comprises the following steps: Step 1, Preparation: the main components Fe2O3, ZnO and Mn3O4 are weighed according to their proportions and mixed by wet ball milling, with a mixing time of 10 to 40 minutes; Step 2, Pre-firing: the mixture obtained from step 1 is dried and pre-fired at 700 °C to 1000 °C, holding the temperature for 1 to 3 hours; Step 3, Grinding: the pre-burned material obtained from step 2 is shaken and the auxiliary components Nano-CaCO3, Nano-TiO2, Nano-Co2O3, Nano-Nb2O5, Nano-SiO2 and Nano-CuO are added according to the proportions, using the fluidized bed airflow milling method to grind the pre-burned material; Step 4, Granulation: the powder is granulated after airflow milling; Step 5, Pressing and Forming: it is pressed into a ring-shaped base body with the dimensions Ø 25mm in diameter * Ø 15mm in diameter * 7.5mm, with a density of 3.15g / cm³. 3 up to 3.35g / cm³ 3 amounts; Step 6, sintering, where the sintering temperature is 1200 to 1280°C, the holding time is 4 to 8 hours and the equilibrium oxygen content is 3.0 to 8.0%. [2] Method according to claim 1, characterized by , that the main components are Fe2O3: 53.0 mol% to 54.0 mol%, ZnO: 16.0 mol% to 17.5 mol%, the remainder is Mn3O4, with the auxiliary components, relative to the total weight of the main components, being Nano-CaCO3: 400 ppm to 800 ppm, Nano-TiO2: 4000 to 6000 ppm, Nano-Co2O3: 500 ppm to 2000 ppm, Nano-Nb2O5: 100 ppm to 300 ppm, Nano-SiO2: 20 ppm to 100 ppm, Nano-CuO: 0 ppm to 600 ppm. [3] Method according to claim 1, characterized by , that in step 2 pre-burning takes place in air, with the temperature increase rate of the pre-burning temperature being 3 °C / minute to 5 °C / minute. [4] Method according to claim 1, characterized by, that in step 3 the crushing time is 30 to 60 minutes, the air pressure is 0.6 to 1.0 MPa and the speed of the classifying wheel is 8000 rpm. [5] Method according to claim 1, characterized by , that in step 3 the D50 particle size range after comminution is 1.0 µm to 1.3 µm and the D90 particle size range is 2.1 µm to 2.6 µm. [6] Method according to claim 1, wherein in step 6 the sintering temperature is 1200 to 1240°C, the holding time is 4 to 8 hours and the equilibrium oxygen content is 3.0 to 8.0%. [7] Method according to claim 1, wherein in step 6 the grain size after sintering is 15 µm to 20 µm. [8] Method according to any one of claims 1 to 7, characterized by, that the specific temperature coefficient of the soft magnetic manganese zinc ferrite with a wide temperature range and high magnetic permeability for automotive electronics in the range of -40 °C to +125 °C is -0.5 to 0.5 and where the magnetic permeability is stably above 5000.

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