阅读说明：本技术 一种低反射性吸波材料及其制备方法 (Low-reflectivity wave-absorbing material and preparation method thereof ) 是由 李坚强 于 2020-07-21 设计创作，主要内容包括：本发明属于吸波材料技术领域,具体涉及一种低反射性吸波材料及其制备方法,将羰基铁加入到发蓝氧化剂水溶液中,搅拌反应后,烘干备用；将3-氨丙基三乙氧基硅烷加入到无水乙醇,同时将氧化羰基铁粉加入到去离子水中,超声振荡使其成为羰基铁悬浊液,将羰基铁悬浊液加入到3-氨丙基三乙氧基硅烷的乙醇溶液中,反应结束后烘干备用；将胶粘剂加入到无水乙醇中充分搅拌至透明,将二氧化硅包覆氧化羰基铁粉和偶联剂一起加入到胶粘剂的乙醇溶液中；将吸收剂胶液放置到烘箱中烘干水分,之后将块体取出研磨成粉体,将粉末放入热压模具中,制成低反射性吸波材料,克服了现有技术的不足,该工艺简单高效,可重复性好,对雷达波吸收效果明显。(The invention belongs to the technical field of wave-absorbing materials, and particularly relates to a low-reflectivity wave-absorbing material and a preparation method thereof, wherein carbonyl iron is added into a bluing oxidant aqueous solution, stirred for reaction, and dried for later use; adding 3-aminopropyltriethoxysilane into absolute ethanol, simultaneously adding carbonyl iron oxide powder into deionized water, performing ultrasonic oscillation to obtain carbonyl iron suspension, adding the carbonyl iron suspension into an ethanol solution of 3-aminopropyltriethoxysilane, and drying for later use after the reaction is finished; adding the adhesive into absolute ethyl alcohol, fully stirring until the mixture is transparent, and adding the silicon dioxide coated carbonyl oxide iron powder and the coupling agent into an ethanol solution of the adhesive; the absorbent glue solution is placed in an oven to dry water, then the block is taken out and ground into powder, and the powder is placed in a hot-pressing die to prepare the low-reflectivity wave-absorbing material.)

1. A preparation method of a low-reflectivity wave-absorbing material is characterized by comprising the following steps: comprises the following steps of (a) carrying out,

step one, weighing a proper amount of carbonyl iron, slowly adding the carbonyl iron into a bluing oxidant aqueous solution under the oil bath heating condition, stirring and reacting for a certain time, pouring out supernatant liquid, repeatedly cleaning with distilled water, and drying for later use to prepare carbonyl iron oxide powder;

step two, weighing a proper amount of 3-aminopropyltriethoxysilane, adding the 3-aminopropyltriethoxysilane into absolute ethyl alcohol, simultaneously adding the dried carbonyl iron oxide powder in the step one into deionized water, carrying out ultrasonic oscillation to obtain carbonyl iron suspension, adding the carbonyl iron suspension into an ethanol solution of the 3-aminopropyltriethoxysilane, reacting under the condition of stirring and constant-temperature water bath, repeatedly cleaning by using the absolute ethyl alcohol and distilled water after the reaction is finished, and drying for later use to obtain silicon dioxide coated carbonyl iron oxide powder;

step three, weighing a proper amount of adhesive and coupling agent, adding the adhesive into absolute ethyl alcohol, fully stirring until the adhesive is transparent, adding the silicon dioxide coated carbonyl oxide iron powder obtained in the step two and the coupling agent into an ethanol solution of the adhesive, fully mechanically stirring and ultrasonically treating to obtain an absorbent glue solution;

and step four, placing the absorbent glue solution prepared in the step three into an oven at 240 ℃ to dry water, taking the block out, grinding the block into powder in a ball mill, and placing the powder into a hot-pressing die to prepare the low-reflectivity wave-absorbing material.

2. The method for preparing the low-reflectivity wave-absorbing material of claim 1, wherein the method comprises the following steps: in the first step, the bluing oxidant is prepared from sodium hydroxide, sodium nitrite and sodium nitrate according to the mass ratio of 1:1:1, the mass ratio of the carbonyl iron to the bluing oxidant is (1-1.5):1, and the carbonyl iron is oxidized in the bluing oxidant for 60 min.

3. The method for preparing the low-reflectivity wave-absorbing material of claim 1, wherein the method comprises the following steps: the mass ratio of the volume of the 3-aminopropyltriethoxysilane to the silicon dioxide coated carbonyl oxide iron powder in the second step is (2-3) ml: 1g of the total weight of the composition.

4. The method for preparing the low-reflectivity wave-absorbing material of claim 1, wherein the method comprises the following steps: and in the third step, the adhesive is one of organic silicon resin, polyimide resin and boron phenolic resin, and the addition amount of the adhesive is 2-8% of the weight of the silicon dioxide coated carbonyl oxide iron powder.

5. The method for preparing the low-reflectivity wave-absorbing material of claim 1, wherein the method comprises the following steps: in the third step, the coupling agent is titanate, and the addition amount of the coupling agent is 0.1-2% of the weight of the silicon dioxide coated carbonyl oxide iron powder.

6. A low-reflectivity wave-absorbing material is characterized in that: is prepared by the preparation method of any one of claims 1 to 6.

Technical Field

The invention belongs to the technical field of wave-absorbing materials, and particularly relates to a low-reflectivity wave-absorbing material and a preparation method thereof.

Background

With the development of stealth technology and the stealth requirement of high-temperature components of weaponry, the traditional 'thin, wide, light and strong' can not completely meet the requirements of new-generation aerial weaponry on radar wave absorbing materials, and the development of the wave absorbing materials with good wave absorbing performance and high temperature resistance is more and more highly regarded by countries in the world. The wave-absorbing coating has strong adaptability to the appearance of a target, is simple to construct, is particularly suitable for the existing weapons, has small change to the equipment, has small influence on the maneuvering performance and the fire performance of weapon systems, and the like, so that the wave-absorbing coating is widely researched, the research on the wave-absorbing coating at present mainly focuses on the field of normal-temperature wave-absorbing coatings, and the research reports on high-temperature wave-absorbing coatings are few. Carbonyl iron powder is one of the most commonly used radar wave absorbers at present as a typical magnetic loss type absorber, and the Curie temperature of the carbonyl iron powder is as high as 770 ℃.

How to enhance the wave absorbing performance and the stability of carbonyl iron powder under high temperature condition becomes a problem to be solved urgently in the industry.

Disclosure of Invention

The invention aims to provide a low-reflectivity wave-absorbing material and a preparation method thereof, overcomes the defects of the prior art, has simple and efficient process, good repeatability and obvious radar wave absorption effect, and shows wide application prospect in the field of radar wave stealth and the field of electromagnetic shielding.

In order to solve the problems, the technical scheme adopted by the invention is as follows:

a low-reflectivity wave-absorbing material and its preparation method, including the following steps,

step one, weighing a proper amount of carbonyl iron, slowly adding the carbonyl iron into a bluing oxidant aqueous solution under the oil bath heating condition, stirring and reacting for a certain time, pouring out supernatant liquid, repeatedly cleaning with distilled water, and drying for later use to prepare carbonyl iron oxide powder;

step two, weighing a proper amount of 3-aminopropyltriethoxysilane, adding the 3-aminopropyltriethoxysilane into absolute ethyl alcohol, simultaneously adding the dried carbonyl iron oxide powder in the step one into deionized water, carrying out ultrasonic oscillation to obtain carbonyl iron suspension, adding the carbonyl iron suspension into an ethanol solution of the 3-aminopropyltriethoxysilane, reacting under the condition of stirring and constant-temperature water bath, repeatedly cleaning by using the absolute ethyl alcohol and distilled water after the reaction is finished, and drying for later use to obtain silicon dioxide coated carbonyl iron oxide powder;

step three, weighing a proper amount of adhesive and coupling agent, adding the adhesive into absolute ethyl alcohol, fully stirring until the adhesive is transparent, adding the silicon dioxide coated carbonyl oxide iron powder obtained in the step two and the coupling agent into an ethanol solution of the adhesive, fully mechanically stirring and ultrasonically treating to obtain an absorbent glue solution;

and step four, placing the absorbent glue solution prepared in the step three into an oven at 240 ℃ to dry water, taking the block out, grinding the block into powder in a ball mill, and placing the powder into a hot-pressing die to prepare the low-reflectivity wave-absorbing material.

Further, in the first step, the bluing oxidant is prepared from sodium hydroxide, sodium nitrite and sodium nitrate according to the mass ratio of 1:1:1, the mass ratio of the carbonyl iron to the bluing oxidant is (1-1.5):1, and the carbonyl iron is oxidized in the bluing oxidant for 60 min.

Further, the mass ratio of the volume of the 3-aminopropyltriethoxysilane to the silicon dioxide coated carbonyl iron oxide powder in the second step is (2-3) ml: 1g of the total weight of the composition.

Further, the adhesive in the third step is one of organic silicon resin, polyimide resin and boron phenolic resin, and the addition amount of the adhesive is 2-8% of the weight of the silicon dioxide coated carbonyl oxide iron powder.

Further, in the third step, the coupling agent is titanate, and the addition amount of the coupling agent is 0.1-2% of the weight of the silicon dioxide coated carbonyl iron oxide powder.

A low-reflectivity wave-absorbing material is prepared by a method for preparing a raw material and a hydrophobic material.

Compared with the prior art, the invention has the following beneficial effects:

the invention improves the wave absorbing performance and the thermal stability of the hydroxyl iron by oxidizing and modifying the carbonyl iron, and has good overall performance, low surface density and wide absorption frequency band. The process is simple and efficient, has good repeatability and obvious radar wave absorption effect, and shows wide application prospects in the radar wave stealth field and the electromagnetic shielding field.

Drawings

Fig. 1 is an SEM image of the low-reflectivity wave-absorbing material provided in example 1.

Fig. 2 is a schematic diagram of electromagnetic parameters of the low-reflectivity wave-absorbing material provided in example 1 and the wave-absorbing material provided in comparative example 1 (a is a real dielectric constant part, b is a real dielectric constant part, c is a real permeability part, and d is an imaginary permeability part).

Fig. 3 is a line graph of reflectivity values of the low-reflectivity wave-absorbing material provided in example 1 and the wave-absorbing material provided in comparative example 1 before and after high-temperature treatment at 250 ℃.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.