Electromagnetic wave absorbing silicon-carbide material coated with barium ferrite film and its preparation process

A barium ferrite and electromagnetic wave-absorbing technology, which is applied to electrical components, other chemical processes, and instrument parts, can solve problems such as large specific gravity, poor practical effect, and narrow frequency band of ferrite coatings

Inactive Publication Date: 2008-12-24
TONGJI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

When ferrite is used as a wave absorbing agent, there is mainly the problem of large specificity, and the traditional ferrite coating has a narrow frequency band, and the actual effect is poor.

Method used

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  • Electromagnetic wave absorbing silicon-carbide material coated with barium ferrite film and its preparation process
  • Electromagnetic wave absorbing silicon-carbide material coated with barium ferrite film and its preparation process
  • Electromagnetic wave absorbing silicon-carbide material coated with barium ferrite film and its preparation process

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] The precursor was prepared by complexing ferric nitrate and barium nitrate with citric acid. According to the stoichiometric ratio of Ba(NO 3 ) 2 : Fe(NO 3 ) 3 : citric acid = 1:12:19 to prepare a solution. Silicon carbide is added to the solution. The theoretical product mass ratio of silicon carbide and ferrite is 1:1. Ammonia water was added dropwise to adjust the pH to 7. The solution was placed in a 90°C water bath and stirred for 4 to 5 hours until the liquid became a viscous colloid. The prepared sol was placed in an oven at 120 °C for 4 h to obtain a dry gel. The resulting gel was heated in a muffle furnace. Heating and heating rate: 60°C / h, when the temperature is raised to 850°C, the temperature is kept for 1h.

Embodiment 2

[0027] The precursor was prepared by complexing ferric nitrate and barium nitrate with citric acid. According to the stoichiometric ratio of Ba(NO 3 ) 2 : Fe(NO 3 ) 3 : citric acid = 1 : 12: 13 to prepare a solution. Silicon carbide is added to the solution. The theoretical product mass ratio of silicon carbide and ferrite is 2:1. Ammonia water was added dropwise to adjust the pH to 7. The solution was placed in a 90°C water bath and stirred for 4 to 5 hours until the liquid became a viscous colloid. The prepared sol was placed in an oven at 120 °C for 5 h to obtain a dry gel. The resulting gel was heated in a muffle furnace. Heating and heating rate: 30°C / h, when the temperature is raised to 750°C, the temperature is kept for 3h.

Embodiment 3

[0029] The precursor was prepared by complexing ferric nitrate and barium nitrate with citric acid. According to the stoichiometric ratio of Ba(NO 3 ) 2 : Fe(NO 3 ) 3 : citric acid = 1:12:15 to prepare a solution. Silicon carbide is added to the solution. The theoretical product mass ratio of silicon carbide and ferrite is 1:1.5. Ammonia water was added dropwise to adjust the pH to 7. The solution was placed in a 90°C water bath and stirred for 4 to 5 hours until the liquid became a viscous colloid. The prepared sol was placed in an oven at 120 °C for 5 h to obtain a dry gel. The resulting gel was heated in a muffle furnace. Heating and heating rate: 100°C / h, when the temperature is raised to 800°C, the temperature is kept for 2h.

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Abstract

An electromagnetic wave absorbing silicon-carbide particle coated by baruim ferrite film is prepared by citrate sol-gel method, that is, proportionally coating the barium ferrite film on the surface of silicon carbide particle. It can be used for wave absorbing coating.

Description

technical field [0001] The invention relates to a composite wave absorbing material and a preparation process thereof, in particular to a silicon carbide electromagnetic wave absorbing material coated with a barium ferrite film and a preparation process thereof. Background technique [0002] Electromagnetic radiation has a great impact on the living environment and working environment. Environmental electromagnetic pollution has attracted people's attention. Many countries have formulated corresponding electromagnetic radiation safety standards. With the improvement of the living standard of the whole society and the enhancement of people's awareness of environmental protection and health care, the requirements for electromagnetic wave pollution control will become one of the important indicators of environmental protection. In the range covered by electromagnetic radiation (public buildings, public places, residential areas, etc.), measures are taken from the building itsel...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C09K3/00G12B17/02H05K9/00C09D1/00
Inventor 张晏清张雄
Owner TONGJI UNIV
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