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CN-121974671-A - Core-shell type high-loss ferrite electromagnetic material and preparation method thereof

CN121974671ACN 121974671 ACN121974671 ACN 121974671ACN-121974671-A

Abstract

The invention discloses a core-shell type high-loss ferrite electromagnetic material and a preparation method thereof, wherein the core-shell type high-loss ferrite electromagnetic material comprises a shell layer and a core layer, the shell layer is a carbon sphere, the core layer is an M-Ba ferrite material, the mass ratio of the shell layer to the core layer is 1 (5-15), the molecular formula of the M-Ba ferrite material is BaFe 12‑x Al x O 19 , wherein x=0.0-1.0. The invention utilizes the characteristics of high-frequency application, high-temperature resistance, stable process and the like of BaFe 12‑x Al x O 19 ferrite, combines the carbon spheres prepared from potato starch for core-shell type compounding, has high loss constant and high temperature stability in a high frequency band, and can meet the application requirements of electromagnetic shielding and electromagnetic loss type under high frequency.

Inventors

  • SHAN YUCAI
  • YANG HAITANG
  • LIU RUI
  • Li yinrui
  • TAN WENKANG
  • HUANG XIN

Assignees

  • 成都飞机工业（集团）有限责任公司

Dates

Publication Date
20260505
Application Date
20260122

Claims (8)

  1. 1. A core-shell type high-loss ferrite electromagnetic material is characterized by comprising a shell layer and a core layer, wherein the shell layer is a carbon sphere, the core layer is an M-Ba ferrite material, and the mass ratio of the shell layer to the core layer is 1 (5-15), and the molecular formula of the M-Ba ferrite material is BaFe 12-x Al x O 19 ; Wherein x=0.0 to 1.0.
  2. 2. The core-shell high-loss ferrite electromagnetic material according to claim 1, wherein x=0.0 to 0.3.
  3. 3. A core-shell high loss ferrite electromagnetic material according to claim 2, wherein x = 0.1.
  4. 4. The preparation method of the core-shell type high-loss ferrite electromagnetic material is characterized by comprising the following steps of: Step S1, weighing reactants according to the stoichiometric ratio of BaFe 12-x Al x O 19 , wherein the reactants comprise barium carbonate, ferric oxide and aluminum oxide; s2, preparing BaFe 12-x Al x O 19 ferrite powder based on a solid phase sintering method; s3, preparing potato starch solution based on ionized water; S4, adding the potato starch solution and the BaFe 12-x Al x O 19 ferrite powder prepared in the step S2 into a reaction kettle; s5, setting the temperature of the reaction kettle to be 180-220 ℃ and preserving the heat for 2-10 hours; And S6, after the reaction is finished, cooling to room temperature to prepare the core-shell type high-loss ferrite electromagnetic material.
  5. 5. The method for preparing the core-shell type high-loss ferrite electromagnetic material according to claim 4, wherein in the step S3, the mass ratio of deionized water to potato starch in a potato starch solution is 10:2, and in the step S4, the mass ratio of potato starch to BaFe 12-x Al x O 19 ferrite powder is (5-15): 1.
  6. 6. The method for preparing a core-shell type high-loss ferrite electromagnetic material according to claim 4, wherein the step S2 comprises the steps of: Step S21, placing the reactant weighed in the step S1 into a polytetrafluoroethylene or nylon ball milling tank, performing ball milling once, taking out and drying after ball milling is finished, and then presintering in a high-temperature furnace at 1100-1200 ℃ for 1-6 hours to obtain presintering powder; s22, carrying out secondary ball milling on the presintered powder obtained in the step S21, and taking out drying treatment after ball milling is finished to obtain dried powder granulation; And S23, granulating the dried powder obtained in the step S22, sintering, wherein the temperature rising rate is 1-5 ℃ per minute, the sintering temperature is 1220-1280 ℃, and the heat preservation time is 1-8 hours, so as to obtain the BaFe 12-x Al x O 19 ferrite powder.
  7. 7. The method for preparing a core-shell type high-loss ferrite electromagnetic material according to claim 6, wherein in the step S21 and the step S22, zirconium oxide and deionized water are respectively adopted as grinding media for the primary ball milling and the secondary ball milling, the ball milling time is 16-24 hours, and the rotating speed is 200-280 rpm.
  8. 8. The method for preparing a core-shell type high-loss ferrite electromagnetic material according to claim 6, wherein in the step S21 and the step S22, the drying temperature is 60 ℃ to 120 ℃.

Description

Core-shell type high-loss ferrite electromagnetic material and preparation method thereof Technical Field The invention belongs to the technical field of wave-absorbing materials, and particularly relates to a core-shell type high-loss ferrite electromagnetic material and a preparation method thereof. Background An electron shielding or electromagnetic lossy material is a material that is used to shield or attenuate electromagnetic radiation. It plays an important role in various application scenarios, such as isolation of electronic devices, communication systems and building structures. How to select the proper electronic shielding or electromagnetic loss type material is also a key issue for designers. For electronic devices, electromagnetic radiation can cause unwanted interference and noise. In communication systems, particularly wireless communication systems, electromagnetic radiation can cause signal interference and leakage, affecting communication quality and security. The electronic shielding or electromagnetic loss type material can effectively shield electromagnetic radiation, so that the problems are avoided, and the performance and the reliability of the equipment are improved. For example, ferrite materials can effectively absorb electromagnetic waves, and reduce the influence of the electromagnetic waves on equipment. The electromagnetic loss type material can convert electromagnetic waves into heat energy, so that the shielding effect is achieved. In summary, the electronic shielding or electromagnetic loss type materials are widely used in electronic devices and communication systems. As the integration level of electronic systems becomes higher, the problem of electromagnetic interference becomes more serious, and new materials with high curie temperature, high application frequency and high loss characteristics are needed. Electronic shielding or electromagnetic loss type materials in electronic systems have been increasingly studied in recent years. For example, the prior Chinese patent CN113161762B discloses a metal/sericin-based carbon nano composite wave-absorbing material with a core-shell structure and a preparation method thereof. The method utilizes the coordination reaction of sericin and metal salt to generate a complex, and then carbonizes the complex to obtain the metal/carbon composite wave-absorbing material of the carbon-coated metal nano particles, and the impedance matching capability of the composite material can be regulated by doping different metals one by one so as to regulate and control the electromagnetic loss performance of the composite material. But the preparation process is complex, the cost is high, and the large-scale use is not facilitated. The prior Chinese patent CN118047418A discloses a manganese-zinc ferrite wave-absorbing material with low-frequency absorption performance, a preparation method and application thereof, which belong to the technical field of microwave absorbing materials, and under the actions of a precipitator, a surfactant and the like, metal ions are subjected to precipitation reaction in a solution system by adopting a coprecipitation method, so as to obtain the manganese-zinc ferrite electromagnetic loss type material. The shielding/electromagnetic loss type material has better performance and lower cost, but has relatively lower frequency, thus limiting the use in the current high-frequency field. The prior Chinese patent CN118006300A discloses a wave-absorbing material with a multilayer core-shell structure and a preparation method thereof, an inner core composed of carbon oxide nanohorns, an intermediate layer composed of polyaniline and coating the inner core, and an outer shell composed of titanium dioxide and coating the intermediate layer. However, since the process includes organic matters such as polyaniline, the high temperature resistance is poor, and there is a limitation in that the preparation process is complicated and the consistency is poor. Disclosure of Invention The invention aims to provide a core-shell type high-loss ferrite electromagnetic material and a preparation method thereof, and aims to provide an electromagnetic material with high loss and high temperature stability so as to meet the application requirements of electromagnetic shielding and electromagnetic loss under high frequency. The invention is realized mainly by the following technical scheme: The core-shell type high-loss ferrite electromagnetic material comprises a shell layer and a core layer, wherein the shell layer is a carbon sphere, the core layer is an M-Ba ferrite material, and the mass ratio of the shell layer to the core layer is1 (5-15), and the molecular formula of the M-Ba ferrite material is BaFe 12-xAlxO19; Wherein x=0.0 to 1.0. In order to better implement the present invention, further, x=0.0 to 0.3. In order to better implement the present invention, further, the x=0.1. The invention is realized mainly by the following techn