Preparation method of sheet-type carbonyl iron powder microwave absorber

A microwave absorbing agent, carbonyl iron powder technology, applied in the direction of magnetic materials, inorganic material magnetism, electrical components, etc., can solve the problems of impedance mismatch, wave absorption performance decline, dielectric constant increase, etc., to achieve magnetic loss and dielectric constant. The effect of increased loss, increased length-to-thickness ratio, and increased ball-to-material ratio

Active Publication Date: 2018-06-29
KING STRONG MATERIAL ENG LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, while the magnetic permeability of flaky carbonyl iron powder increases, its dielectric constant also increases significantly, resulting in impedance mismatch, and the absorption performance will be reduced.

Method used

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  • Preparation method of sheet-type carbonyl iron powder microwave absorber
  • Preparation method of sheet-type carbonyl iron powder microwave absorber
  • Preparation method of sheet-type carbonyl iron powder microwave absorber

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] (1) Add 60 kg of zirconia grinding balls with a diameter of 6 mm and 2 kg of spherical carbonyl iron powder with an average particle size of 3 μm into a stainless steel vacuum grinding tank lined with alumina, and then add 10 L of absolute ethanol as a morphology control agent.

[0034] (2) Vacuum the grinding tank and replace it with nitrogen, and then carry out wet stirring ball milling under the protection of nitrogen, with a stirring speed of 260 rpm and a grinding time of 8 hours.

[0035] (3) Filter the spherical micron carbonyl iron powder after ball milling, collect the solid and vacuum-dry it at 60°C for 12 hours, and pass high-purity nitrogen gas every 3 hours to replace the volatilized anhydrous ethanol, and then re-evacuate.

[0036] (4) Under the protection of nitrogen, the dried powder was subjected to airflow milling for ultrafine dispersion, and airflow milling at a pressure of 0.4 MPa for 15 minutes. The obtained monodisperse flake-shaped carbonyl iron ...

Embodiment 2

[0039] (1) Add 120 kg of zirconia grinding balls with a diameter of 6 mm and 2 kg of spherical carbonyl iron powder with an average particle size of 3 μm into a stainless steel vacuum grinding tank lined with alumina, and then add 15 L of absolute ethanol as a shape control agent.

[0040] (2) Vacuumize the grinding tank and replace it with nitrogen, and then carry out wet stirring ball milling under the protection of nitrogen, with a stirring speed of 260rpm and a stirring time of 10h.

[0041] (3) Filter the spherical micron carbonyl iron powder after ball milling, collect the solid and vacuum-dry it at 60°C for 12 hours, and pass high-purity nitrogen gas every 3 hours to replace the volatilized anhydrous ethanol, and then re-evacuate.

[0042] (4) Then, under the protection of nitrogen, the dried powder was subjected to airflow milling for ultrafine dispersion, and airflow milling at a pressure of 0.6MPa for 10 minutes. The obtained monodisperse flake carbonyl iron powder h...

Embodiment 3

[0045] (1) Add 180 kg of zirconia grinding balls with a diameter of 6 mm and 2 kg of spherical carbonyl iron powder with an average particle size of 3 μm into a stainless steel vacuum grinding tank lined with alumina, and then add 20 L of absolute ethanol as a shape control agent.

[0046] (2) Vacuum the grinding tank and replace it with nitrogen, and then carry out wet stirring ball milling under the protection of nitrogen, with a grinding speed of 260 rpm and a grinding time of 12 hours.

[0047] (3) Filter the spherical micron carbonyl iron powder after ball milling, collect the solid and vacuum-dry it at 60°C for 12 hours, and pass high-purity nitrogen gas every 3 hours to replace the volatilized anhydrous ethanol, and then re-evacuate.

[0048] (4) Under the protection of nitrogen, the dried powder is subjected to airflow milling for ultrafine dispersion, and airflow milling at a pressure of 0.5 MPa for 12 minutes. The obtained monodisperse flake carbonyl iron powder has ...

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Abstract

The invention discloses a preparation method of a sheet-type carbonyl iron powder microwave absorbent. The preparation method comprises the following steps: adding grinding balls and spherical micron carbonyl iron powder to a mill tank according to different ratios of balls to materials; adding a morphology control agent, vacuumizing and then filling nitrogen; carrying out wet stirring and ball-milling under nitrogen protection; collecting solids after filtering and carrying out vacuum drying; and carrying out ultrafine airflow dispersion under nitrogen protection. According to the method, spherical carbonyl iron powder can become sheet-type carbonyl iron powder. The micron-size sheet-type carbonyl iron powder is an anisotropic material, so that the sheet-type carbonyl iron powder microwave absorbent has a low percolation threshold and high specific surface area, and is beneficial to formation of a conductive network; the magnetic loss and the dielectric loss can be significantly strengthened; the matching characteristic and the microwave absorbing properties of the material are improved; and the effective bandwidth is expanded.

Description

technical field [0001] The invention relates to the technical field of electromagnetic functional materials, in particular to a preparation method of a plate-shaped carbonyl iron powder microwave absorber with a nanocrystalline structure. Background technique [0002] In order to improve the survivability of military targets in war and the penetration and deep strike capabilities of weapon systems, the development and application of stealth technology has become an important direction for the development of the national defense system. The use of microwave-absorbing materials as an effective means to improve the survivability and penetration capabilities of weapon systems is a military high-tech that countries around the world have focused on developing. As a typical magnetic loss radar wave absorber, carbonyl iron powder has the advantages of high saturation magnetization, low cost and high temperature stability. However, the isotropic spherical carbonyl iron powder absorb...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01F1/147H01F1/20B22F9/04
CPCB22F9/04B22F2009/043H01F1/147H01F1/20
Inventor 赵立英王刚
Owner KING STRONG MATERIAL ENG LTD
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