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A niobium-doped barium ferrite wave-absorbing powder material and its preparation method

A technology of barium ferrite and powder materials, which is applied in the field of niobium-doped barium ferrite absorbing powder materials and its preparation, can solve problems such as unfavorable applications, achieve energy saving, increase electrical conductivity, and reduce matching thickness Effect

Active Publication Date: 2017-03-29
ZHEJIANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the dielectric loss value of Ti-doped barium ferrite is relatively small, and the dielectric loss controls the thickness of the absorbing layer that must be satisfied when forming a matching resonance to a large extent, so that Ti-doped ferrite The matching thickness of the body must be thicker at about 2.8mm, which is obviously unfavorable for the application

Method used

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  • A niobium-doped barium ferrite wave-absorbing powder material and its preparation method
  • A niobium-doped barium ferrite wave-absorbing powder material and its preparation method
  • A niobium-doped barium ferrite wave-absorbing powder material and its preparation method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] 1) Mix barium nitrate, ferric nitrate, niobium oxalate and citric acid in a molar ratio of 1:11.4:0.6:19.6, add deionized water and stir for 3 hours to dissolve to obtain solution A, wherein the total molar concentration of barium nitrate, ferric nitrate and niobium oxalate 1.5mol / L;

[0029] 2) adjusting the pH value of solution A in step 1) to 5 to obtain solution B;

[0030] 3) Move the solution B in step 2) to a clean stainless steel basin, place it on an electronic universal furnace, adjust the power to 600W, and perform self-propagating combustion to obtain the precursor powder;

[0031] 4) Add the precursor powder of step 3) into absolute ethanol, add 10 g of precursor powder per 100 mL of absolute ethanol, and ball mill at a speed of 300 r / min for 12 hours to obtain a turbid liquid;

[0032] 5) Dry the above turbid liquid at 70°C for 5 days, collect the dry powder and place it in a vacuum furnace, raise the temperature to 400°C at a rate of 5°C / min and keep it ...

Embodiment 2

[0036] 1) Mix barium nitrate, ferric nitrate, niobium oxalate and citric acid in a molar ratio of 1:11.3:0.7:19.7, add deionized water and stir for 4 hours to dissolve to obtain solution A, in which the total molar concentration of barium nitrate, ferric nitrate and niobium oxalate 2.0mol / L;

[0037] 2) adjusting the pH value of solution A in step 1) to 6 to obtain solution B;

[0038] 3) Move the solution B in step 2) to a clean stainless steel basin, place it on an electronic universal furnace, adjust the power to 700W, and perform self-propagating combustion to obtain the precursor powder;

[0039] 4) Add the precursor powder in step 3) to absolute ethanol, add 10 g of precursor powder per 200 mL of absolute ethanol, and ball mill at a speed of 400 r / min for 10 h to obtain a cloudy liquid;

[0040] 5) Dry the above turbid liquid at 80°C for 4 days, collect the dry powder and place it in a vacuum furnace, raise the temperature to 500°C at a rate of 10°C / min and keep it for ...

Embodiment 3

[0044] 1) Mix barium nitrate, ferric nitrate, niobium oxalate and citric acid in a molar ratio of 1:11.2:0.8:19.8, add deionized water and stir for 5 hours to dissolve to obtain solution A, in which the total molar concentration of barium nitrate, ferric nitrate and niobium oxalate 2.5mol / L;

[0045] 2) adjusting the pH value of solution A in step 1) to 7 to obtain solution B;

[0046] 3) Move the solution B in step 2) to a clean stainless steel basin, place it on an electronic universal furnace, adjust the power to 800W, and perform self-propagating combustion to obtain the precursor powder;

[0047] 4) Add the precursor powder of step 3) into absolute ethanol, add 10 g of precursor powder per 300 mL of absolute ethanol, and ball mill at a speed of 500 r / min for 8 hours to obtain a turbid liquid;

[0048] 5) Dry the above turbid liquid at 90°C for 3 days, collect the dry powder and place it in a vacuum furnace, raise the temperature to 600°C at a rate of 15°C / min and keep it...

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Abstract

The invention discloses a niobium-doped barium ferrite wave-absorbing powder material, with the chemical formula of BaFe(12-x)NbxO19, wherein x is equal to 0.6-0.8, the niobium-doped barium ferrite is a single-phase polycrystalline powder body, and also contains Fe<3+> and Fe<2+>. A preparation method comprises the following steps: performing ball milling and subsequent secondary vacuum high-temperature thermal treatment by adopting a self-propagating combustion method, to obtain the niobium-doped barium ferrite wave-absorbing powder material. The wave-absorbing material has the characteristic of being thin in matching thickness and wide in wave-absorbing band, the effective wave-absorbing band is controlled within the frequency range of 23-40GHz, double-absorption peak appears, the effective absorption band width is about 15GHz, the optimal matching thickness is about 0.8mm, and the best reflection loss RL value at the specific frequency can achieve 42dB. The niobium-doped barium ferrite wave-absorbing powder material is simple in preparation method, can be used as a wave-absorbing coating, and has wide application in the electromagnetic shielding and invisibility fields.

Description

technical field [0001] The invention relates to a niobium-doped barium ferrite wave-absorbing powder material and a preparation method thereof, belonging to the technical field of wave-absorbing materials. Background technique [0002] As stealth technology is widely used in military fields such as missiles, aircraft, and ships, it has become one of the indispensable high-tech for military modernization. However, the rapid development of monitoring technology such as radar has put forward new requirements for modern stealth technology. As one of the frontier topics in stealth technology, absorbing materials need to develop in the direction of large absorbing loss, wide absorbing frequency, light weight and thin thickness. In addition, with the development of electronic information technology, electromagnetic pollution has become an urgent problem to be solved in today's society. It can be seen that absorbing materials have important research significance in both military a...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C04B35/26C04B35/622
Inventor 杜丕一刘初阳马宁韩高荣翁文剑
Owner ZHEJIANG UNIV
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