CN101259463A - A kind of preparation method of foamed aluminum alloy base absorbing material - Google Patents

Abstract

A method for preparing a foamed aluminum alloy-based wave-absorbing material. Including the surface pretreatment of the foamed aluminum alloy material, the preparation of the wave absorbing agent coating and the spraying steps of the foamed aluminum alloy material, it is characterized in that: the foamed aluminum alloy material that has undergone degreasing treatment and sandblasting treatment is used as the substrate, and the surface is coated with A single wave-absorbing coating or a composite wave-absorbing coating is prepared into a single wave-absorbing agent foamed aluminum alloy-based wave-absorbing material or a composite wave-absorbing agent foamed aluminum alloy-based wave-absorbing material. The product of the invention provides a new idea for the development of wave-absorbing materials, provides a new field for the popularization and application of foam metal materials, and also lays a theoretical and technological foundation for the development of porous material-based wave-absorbing materials.

Description

A kind of preparation method of foamed aluminum alloy base absorbing material

technical field

The invention belongs to the technical field of material science, and in particular relates to a preparation method of a foamed aluminum alloy-based wave-absorbing material.

Background technique

Absorbing materials are developing in the direction of "thin, light, wide, and strong". Studies have shown that the absorbing performance of dense absorbing materials has been significantly improved after being made porous, and the density of the materials can be greatly reduced at the same time. However, the research reports on porous absorbing materials are relatively rare, and the analysis of its absorbing mechanism is still in the preliminary stage. Porous metal foam is a new type of porous lightweight metal material. People have systematically studied its damping, impact resistance, sound absorption and shock absorption, electromagnetic wave shielding and other properties, but few people have studied its absorbing performance.

Contents of the invention

The purpose of the present invention is to provide a method for preparing a foamed aluminum alloy-based wave-absorbing material, especially a method for coating a wave-absorbing coating on the surface of a porous foamed aluminum alloy material to obtain a new lightweight wave-absorbing material.

Studies have shown that the foamed aluminum alloy material with a relative density of 0.111-0.185 and an average pore diameter of 6-7mm has certain wave-absorbing performance in the Ka-band electromagnetic wave (electromagnetic wave with a frequency range of 26.5-40GHz'), and the surface is coated with dielectric materials. Type wave absorbing agent, resistance type wave absorbing agent and magnetic medium type wave absorbing agent can play the role of porous structure and absorbing coating on the absorption and loss of electromagnetic waves at the same time, so that the material can obtain a wave absorbing performance lower than -10dB, and the composite The absorbing agent is coated on the surface of the foamed aluminum alloy, and its absorbing performance can be further improved.

In the present invention, a foamed aluminum alloy with a relative density of 0.148 to 0.185 is used as a base material, and a resistance type wave absorber (silicon carbide or polyaniline), a dielectric type wave absorber (barium titanate) and a magnetic medium type absorber are respectively coated on the surface. Wave agent (Ni-Zn ferrite or carbonyl nickel), prepared into a single absorber foam aluminum alloy base absorbing material, test and analyze the absorbing performance of the absorbing material; on this basis, the magnetic medium type absorber Coating with polyaniline wave absorbing agent on the surface of foamed aluminum alloy to prepare composite wave absorbing agent foamed aluminum alloy based wave absorbing material, further improving the wave absorbing performance of foamed aluminum alloy based wave absorbing material.

Technical scheme of the present invention is:

1. Surface pretreatment of porous aluminum alloy foam:

1.1 Surface degreasing treatment of the foamed aluminum alloy substrate: use the foamed aluminum alloy as the substrate, wash the foamed aluminum alloy substrate with room temperature cold water to remove some mechanical debris remaining on the surface and in the pores, and then use an air compressor at a spray pressure of 0.8Mpa Under certain conditions, spray lye to clean the surface of the foamed aluminum alloy substrate, and the temperature of the lye is controlled at 60±3°C to prevent the surface of the foamed aluminum alloy substrate from being corroded; immediately after spraying the lye, rinse it with cold water at room temperature, and then use an ultrasonic cleaner Clean for 15 minutes and use a frequency of 40KHz; then spray the surface with deionized water to remove residual lye; use a hair dryer to shorten the drying time of the surface to avoid the concentration of lye and corrode the surface due to the concentration of hanging water droplets during drying. Then dry it at 100°C.

1.2 Sand blasting treatment of the foamed aluminum alloy substrate: After degreasing the foamed aluminum alloy substrate, use a sandblasting machine for particle sandblasting, in which the diameter of the quartz sand particles is less than 100 μm, the compressed air source is 3.0-7.0kg/cm ² , and the distance is controlled during sandblasting About 100-150mm. During the blasting process, the distance between the spray gun and the foamed aluminum alloy substrate and the blasting pressure should be controlled so as not to damage the surface of the foamed aluminum alloy substrate as much as possible.

After sandblasting, spray and wash repeatedly with anhydrous ethanol to wash off the sand particles on the surface of the foamed aluminum alloy substrate and in the pores, and finally dry it with a hair dryer to complete the surface pretreatment of the foamed aluminum alloy substrate.

2. Preparation of single absorbing coating:

2.1 Coupling pretreatment of wave absorbing agent filler:

Add a coupling agent (silane coupling agent or titanate coupling agent) to the wave absorbing agent (silicon carbide, polyaniline, barium titanate, Ni-Zn ferrite, nickel carbonyl or nano-cobalt) filler powder. The amount of joint agent is 3% of the wave absorbing agent filler powder. Then add the diluent (the diluent is n-butanol: xylene: propylene glycol methyl ether = 6: 4: 1 mixed solution, the amount is 1ml per 4g of wave absorbing agent filler powder), in a high shear force dispersing emulsifier Stir at a speed of 10000r/min for 30min.

2.2 Dispersion of wave absorbing agent filler:

Use the dispersant (B401, B402, CH-10S, CH-13F, CH-13, T70 or 963) with a diluent (the diluent is a mixture of n-butanol:xylene:propylene glycol methyl ether=6:4:1 , the dosage is 1ml when wave absorbing agent filler powder every 4g) dilution, the consumption of dispersing agent is the 2% mass percent of whole wave absorbing agent filler, pour in the wave absorbing agent filler of pretreatment and mix and grind in glass mortar, Complete dispersion of wave absorber filler.

2.3 Preparation of film-forming substances:

The binder epoxy resin (accounting for 30% by mass of the filler and the binder) is mixed with the curing agent polyamide in a mass ratio of 2:1 to prepare a film-forming substance.

2.4 Preparation of absorbing coating:

Mix the prepared film-forming material and the dispersed single wave absorbing agent filler and grind for 5 minutes, then use a high-shear dispersing emulsifier to stir at a speed of 10000r/min for 10 minutes, and then pass through an ultrasonic cleaner at a frequency of 40KHz. Ultrasonic vibration disperses for 20 minutes, and continues to disperse with a high-shear dispersing emulsifier at a speed of 10,000 r/min for 10 minutes. In order to obtain a more delicate coating with less impurities and no air bubbles, the coating was finally sieved with a 120-mesh sieve to prepare a single wave-absorbing coating.

3. Preparation of composite absorbing coating:

3.1 Preparation of composite wave absorbing agent filler:

Add a coupling agent (silane coupling agent or titanate) to the main component (wave absorber filler component with a high mass percentage) of the two wave absorber fillers (polyaniline, Ni-Zn ferrite or nickel carbonyl) coupling agent), the amount of coupling agent is 3% of the wave absorbing agent filler powder, with absolute ethanol (the amount of absolute ethanol is based on the balls and fillers submerged in the ball mill tank) as the medium, put them into the ball mill together Ball mill wet mixing at a speed of 120r/min for 30 minutes in the tank, then add the second component (wave absorber filler component with a low mass percentage relative to the main component) into the ball mill tank, and ball mill wet mixing at a speed of 120r/min for 5 hours; Then dry the wet-mixed materials, remove the absolute ethanol, put them into a ball mill tank and dry-mix them for 5 hours at a speed of 120 r/min.

3.2 Coupling pretreatment of composite wave absorbing agent filler:

A coupling agent (silane coupling agent or titanate coupling agent) is added to the prepared composite wave absorbing agent filler powder, and the amount of the coupling agent is 3% of the total amount of the composite wave absorbing agent filler. Then add the diluent (the diluent is n-butanol: xylene: propylene glycol methyl ether = 6: 4: 1 mixed solution, the amount is 1ml per 4g of wave absorbing agent filler powder), in a high shear force dispersing emulsifier Stir at a speed of 10000r/min for 30min.

3.3 Dispersion of composite absorber filler

Dilute the dispersant with a diluent (the diluent is a mixture of n-butanol: xylene: propylene glycol methyl ether = 6:4:1, the amount used is 1ml when the wave absorber filler powder is 4g), and the amount of the dispersant is all 2% by mass of the wave absorber filler is poured into the pretreated composite wave absorber filler and mixed and ground in a glass mortar to complete the dispersion of the wave absorber filler.

3.4 Preparation of film-forming substances

The binder epoxy resin (accounting for 30% by mass of the filler and the binder) is mixed with the curing agent polyamide in a mass ratio of 2:1 to prepare a film-forming substance.

3.5 Preparation of composite absorbing coating

Mix the prepared film-forming material and the dispersed composite wave-absorbing agent filler and grind for 5 minutes, then stir for 10 minutes with a FA25 high-shear dispersing emulsifier at a speed of 10000r/min, and then pass through a KQ-100 ultrasonic cleaner at a frequency of 40KHz Under the conditions of ultrasonic vibration and dispersion for 20 minutes, continue to disperse with FA25 high-shear dispersing and emulsifying machine at a speed of 10000r/min for 10 minutes. In order to obtain a more delicate coating with less impurities and no air bubbles, the coating was finally sieved with a 120-mesh sieve to prepare a composite wave-absorbing coating.

4. Surface coating of foamed aluminum alloy substrate:

Use an air compressor and a spray gun as the air spraying equipment, and spray the prepared single or composite wave-absorbing coating on the foamed aluminum alloy substrate that has completed surface pretreatment in the fume hood. The spraying amount is 20g. Repeated spraying to ensure that the wave-absorbing coating is evenly coated on each hole of the foamed aluminum alloy substrate. The foamed aluminum alloy substrate after spraying was placed in a blast dryer for curing, the curing temperature was 60°C, and the curing time was 1 h.

The foamed aluminum alloy substrate after spraying and curing is used as a sample of the absorbing material for the electromagnetic wave reflectivity test, and the reflectivity in the Ka band (electromagnetic wave with a frequency range of 26.5-40GHz) is tested. The foamed aluminum alloy base coated with a single wave absorbing agent is a single wave absorbing agent foamed aluminum alloy base absorbing material, and the foamed aluminum alloy base coated with a composite wave absorbing agent is a composite wave absorbing agent foamed aluminum alloy base absorbing material.

The test results of the electromagnetic wave reflectivity of the foamed aluminum alloy-based absorbing material with a single absorbing agent show that the absorbing performance of the absorbing material increases with the increase of the microwave frequency, and there is no obvious peak in the test frequency band, showing the characteristics of the material's broadband . The electromagnetic wave reflectivity test results of the composite absorbing agent foam aluminum alloy based absorbing material show that the absorbing performance of the composite absorbing material has been further improved, in which the surface is coated with Ni-Zn ferrite absorbing agent and nickel carbonyl absorbing The composite absorber foam aluminum alloy based material with additive (Ni-Zn ferrite and carbonyl nickel mass ratio is 3:2) shows excellent absorbing properties, while the surface coated with polyaniline absorber and carbonyl nickel absorber The wave agent (polyaniline and carbonyl nickel mass ratio is 1:2) composite wave absorber foam aluminum alloy base absorbing material is tested in the frequency band of 26.5-40.0GHz for electromagnetic wave reflectivity, and the bandwidth below -10dB can reach 3.18GHz.

Porous metal foam materials have the characteristics of light weight, high porosity, and excellent mechanical properties. Through the research on the electromagnetic wave absorption properties of porous metal foam materials, it is expected to obtain light-weight and efficient wave-absorbing materials, which has important theoretical and practical significance. Experimental research shows that the microwave absorption performance of porous metal foam materials in the microwave frequency range is limited. In order to further improve the microwave absorption performance of the material, the present invention proposes a method for coating the microwave-absorbing coating on its surface. The test results show that the microwave absorption of the material The performance has been improved and has practical application value. In addition, due to the inevitable defects such as holes and cracks in the production process of porous metal foam materials, there are also many impurities, which bring great difficulties to its plating work. The present invention coats the foamed aluminum surface with a wave-absorbing paint, on the one hand, optimizes the wave-absorbing performance of the foamed aluminum alloy, and on the other hand, provides beneficial exploration experience for the beautification of the appearance of the foamed aluminum alloy.

The feature of the present invention is that for the first time, from the perspective of the electromagnetic wave absorption characteristics of the porous foam metal material, this new foam metal material is combined with a traditional and simple coating method, thereby obtaining a new lightweight wave-absorbing material with wave-absorbing properties . The invention not only opens up a new field for the popularization and application of the porous foam metal material, but also provides beneficial exploration experience for the development of new lightweight wave-absorbing materials.

Description of drawings

Figure 1 is a schematic diagram of the surface pretreatment process of foamed aluminum alloy.

Fig. 2 is a coating effect diagram of a foamed aluminum alloy-based wave-absorbing material after the surface of the foamed aluminum alloy material is coated with a wave-absorbing agent.

Figure 3 is the microwave-reflectivity curve of the foamed aluminum alloy-based absorbing material with a single surface absorber in the test frequency range, and the relative density of the foamed aluminum alloy matrix is 0.148-0.185. CfBa represents the microwave-reflectance curve of barium titanate absorber foam aluminum alloy-based absorbing material, CfSi represents the microwave-reflectivity curve of silicon carbide-coated absorber foam aluminum alloy-based absorbing material, and CfFe represents Ni-Zn iron The microwave-reflectivity curve of the oxygen absorber foam aluminum alloy-based absorber, CfNi means the microwave-reflectivity curve of the carbonyl nickel absorber foam aluminum alloy-based absorber, and CfP means the polyaniline absorber foam aluminum alloy The microwave-reflectivity curve of the base absorbing material.

Figure 4 shows the composite wave absorbing agent foamed aluminum alloy based absorbing material with a relative density of 0.148-0.185 (the composite wave absorbing agent foamed aluminum alloy based absorbing material with a mass ratio of Ni-Zn ferrite and carbonyl nickel on the surface is 3:2 wave material) microwave-reflectivity curve,

Figure 5 shows the composition of the composite absorber foam aluminum alloy-based absorber with a relative density of 0.178-0.185 (the composite absorber foam aluminum alloy-based absorber coated with polyaniline and carbonyl nickel at a mass ratio of 1:2) Microwave-reflectivity curve.

Detailed ways

The following are wave absorbing agent fillers, dispersants, diluents, binders, curing agents, coupling agents and foamed aluminum alloy materials used in the examples:

Silicon carbide, polyaniline, barium titanate, Ni-Zn ferrite or nickel carbonyl are used as wave absorbing agent fillers. Among them, the purity of silicon carbide is greater than 95%, and the fineness is 1-2 μm; the purity of polyaniline is greater than 98.0%, and the fineness is less than 30 μm; the purity of barium titanate is greater than 99.9%, and the fineness is 90nm; the fineness of Ni-Zn ferrite is 320 mesh; The purity of nickel is greater than 99.6%, and the fineness is 2.2-2.8 μm.

Use dispersants B401, B402, CH-10S, CH-13F, CH-13, T70 or 963 as dispersants. Among them, B401 and B402 are products of Germany Mingjia Chemical Reagent Co., Ltd., CH-10S, CH-13F and CH-13 are products of Shanghai Sanzheng Polymer Materials Co., Ltd., and T70 and 963 are products of Shenzhen Haichuan Chemical Technology Co., Ltd.

A mixed solution of n-butanol, xylene and propylene glycol methyl ether was used as a diluent, wherein the purity of n-butanol, xylene and propylene glycol methyl ether was analytically pure.

6101 epoxy resin is used as the binder, Bluestar New Materials Wuxi resin product; polyamide is used as the curing agent, product of Tianjin Jinning Sanhe Chemical Co., Ltd.

The silane coupling agent used is KH-550, the product of Qufu Wanda Chemical Co., Ltd.; the titanate coupling agent is JN-115, JN-108, JN-198 or JN-644, Changzhou Jinai Auxiliary Co., Ltd. product.

The relative density of the foamed aluminum alloy material is 0.148-0.185, the average pore diameter is 6-7mm, and the appearance size of the foamed aluminum alloy material is 80mm×80mm.

Example 1:

The foamed aluminum alloy with an appearance size of 80mm×80mm, a relative density of 0.148-0.185, and an average pore diameter of 6-7mm is used as the substrate, and the foamed aluminum alloy substrate is washed with room temperature cold water to remove some mechanical debris remaining on the surface and in the pores. Then use a JD-2025B air compressor to spray lye to clean the surface of the foamed aluminum alloy substrate under the condition of a spray pressure of 0.8Mpa. The temperature of the lye is controlled at 60±3°C to prevent the surface of the foamed aluminum alloy substrate from being corroded. ; Immediately rinse with cold water at room temperature after spraying the lye, and then clean it with a KQ-100 ultrasonic cleaner for 15 minutes, using a frequency of 40KHz; then spray the surface with deionized water to remove residual lye; use a hair dryer to shorten the drying time of the surface to avoid The hanging drops of water will erode the surface due to concentration of lye during drying, and then dry at 100°C after cleaning.

After degreasing the foamed aluminum alloy substrate, use a 9070W wet sandblasting machine for particle sandblasting, in which the diameter of quartz sand particles is less than 100μm, the compressed air source is 3.0-7.0kg/cm ² , and the control distance during sandblasting is about 100-150mm, and the aluminum foam is completed. Alloy substrate surface pretreatment.

Take 20g of polyaniline wave absorbing agent as filler for wave absorbing paint, add silane coupling agent KH-550 to the polyaniline wave absorbing agent, the amount of coupling agent KH-550 is 0.6g, then add 5ml of diluent, diluent It is a mixed solution of n-butanol: xylene: propylene glycol methyl ether = 6:4:1, and it is stirred for 30 minutes at a speed of 10000 r/min in a high-shear force dispersing emulsifier.

Dilute 0.4g of dispersant CH-10S with 5ml of diluent (mixture of n-butanol: xylene: propylene glycol methyl ether = 6:4:1), and pour it into the pretreated wave absorbing agent filler in a glass mortar Mix and grind in medium to complete the dispersion of wave absorber filler.

The binder 6101 epoxy resin and curing agent polyamide were mixed in a mass ratio of 2:1, and the dosage of 6101 epoxy resin was 8.25g to prepare a film-forming substance.

Mix the prepared film-forming material and the dispersed polyaniline wave absorbing agent filler and grind for 5 minutes, then stir for 10 minutes with a FA25 high-shear dispersing emulsifier at a speed of 10000r/min; Under the condition of 40KHz, disperse by ultrasonic oscillation for 20min; continue to disperse with FA25 high-shear dispersing emulsifier at a speed of 10000r/min for 10min; finally, sieve the coating with a 120-mesh sieve to prepare a polyaniline wave-absorbing coating.

Using the JD-2025B air compressor and the W-71G spray gun with a diameter of 1.5mm as the air spraying equipment, spray the prepared polyaniline wave-absorbing coating on the foamed aluminum alloy substrate with surface pretreatment in the fume hood, and spray The amount is 20g. The foamed aluminum alloy substrate after spraying was placed in a 101-1 blast dryer for curing, the curing temperature was 60°C, and the curing time was 1 h.

After spraying and curing, the polyaniline absorber foam aluminum alloy substrate is used as a sample of absorbing material for the electromagnetic wave reflectivity test, and the reflectivity in the Ka band (electromagnetic wave with a frequency range of 26.5-40GHz) is tested.

The CfP curve in Figure 3 is the microwave-reflectivity curve of the polyaniline absorber foam aluminum alloy-based absorbing material. The absorbing effect is the best among many wave absorber foam aluminum alloy materials, up to -12.5dB -10dB bandwidth up to 5.5GHz.

Example 2:

The foamed aluminum alloy with an appearance size of 80 mm × 80 mm, a relative density of 0.148 to 0.185, and an average pore diameter of 6 to 7 mm is used as the substrate, and the surface pretreatment method of the foamed aluminum alloy substrate is the same as in Example 1.

Take 20g of silicon carbide wave absorbing agent as the filler for wave absorbing paint, add titanate coupling agent JN-108 into the silicon carbide wave absorbing agent, the amount of coupling agent JN-108 is 0.6g, and then add 5ml of diluent, The diluent is a mixture of n-butanol: xylene: propylene glycol methyl ether = 6:4:1, and it is stirred at a speed of 10000 r/min for 30 minutes in a high-shear force dispersing emulsifier.

Dilute 0.4g of dispersant CH-13F with 5ml of diluent (mixture of n-butanol: xylene: propylene glycol methyl ether = 6:4:1), and pour it into the pretreated wave absorbing agent filler in a glass mortar Mix and grind in medium to complete the dispersion of wave absorber filler.

The binder 6101 epoxy resin and curing agent polyamide were mixed in a mass ratio of 2:1, and the dosage of 6101 epoxy resin was 8.25g to prepare a film-forming substance.

Mix the prepared film-forming material and the dispersed silicon carbide wave absorbing agent filler and grind for 5 minutes, then stir for 10 minutes with a FA25 high-shear dispersing and emulsifying machine at a speed of 10000r/min; Under the condition of 40KHz, disperse by ultrasonic oscillation for 20min; continue to disperse with FA25 high-shear dispersing emulsifier at a speed of 10000r/min for 10min; finally, sieve the coating with a 120-mesh sieve to prepare a silicon carbide absorbing coating.

Using the JD-2025B air compressor and the W-71G spray gun with a diameter of 1.5mm as the air spraying equipment, spray the prepared silicon carbide wave-absorbing coating on the foamed aluminum alloy substrate that has completed surface pretreatment in the fume hood, and spray The amount is 20g. The foamed aluminum alloy substrate after spraying was placed in a 101-1 blast dryer for curing, the curing temperature was 60°C, and the curing time was 1 h.

After spraying and curing, the silicon carbide absorber foam aluminum alloy substrate is used as the absorbing material sample for the electromagnetic wave reflectivity test, and the reflectivity in the Ka band (electromagnetic wave in the frequency range of 26.5-40GHz) is tested.

The CfSi curve in Figure 3 is the microwave-reflectivity curve of the silicon carbide wave absorber foam aluminum alloy-based wave-absorbing material, and its wave-absorbing efficiency reaches -7.8dB.

Example 3:

The foamed aluminum alloy with an appearance size of 80 mm × 80 mm, a relative density of 0.148 to 0.185, and an average pore diameter of 6 to 7 mm is used as the substrate, and the surface pretreatment method of the foamed aluminum alloy substrate is the same as in Example 1.

Take 20g of barium titanate wave absorbing agent as the filler for wave absorbing paint, add titanate coupling agent JN-198 into the barium titanate wave absorbing agent, the amount of coupling agent JN-198 is 0.6g, and then add 5ml of diluted The diluent is a mixed solution of n-butanol:xylene:propylene glycol methyl ether=6:4:1, which is stirred for 30min at a speed of 10000r/min in a high-shear force dispersing emulsifier.

Dilute 0.4g of dispersant CH-13 with 5ml of diluent (mixture of n-butanol: xylene: propylene glycol methyl ether = 6:4:1), pour it into the pretreated wave-absorbing agent filler in a glass mortar Mix and grind in medium to complete the dispersion of wave absorber filler.

The binder 6101 epoxy resin and curing agent polyamide were mixed in a mass ratio of 2:1, and the dosage of 6101 epoxy resin was 8.25g to prepare a film-forming substance.

Mix the prepared film-forming material and the dispersed barium titanate wave absorbing agent filler and grind for 5 minutes, then stir for 10 minutes with a FA25 high-shear dispersing and emulsifying machine at a speed of 10000r/min; Under the condition of frequency 40KHz, disperse by ultrasonic oscillation for 20min; continue to disperse with FA25 high-shear dispersing emulsifier at a speed of 10000r/min for 10min; finally, sieve the coating with a 120-mesh sieve to prepare a barium titanate absorbing coating.

Using a JD-2025B air compressor and a W-71G spray gun with a diameter of 1.5mm as the air spraying equipment, spray the prepared barium titanate wave-absorbing coating on the foamed aluminum alloy substrate that has completed surface pretreatment in a fume hood. The spray amount is 20g. The foamed aluminum alloy substrate after spraying was placed in a 101-1 blast dryer for curing, the curing temperature was 60°C, and the curing time was 1 h.

After spraying and curing, the barium titanate wave absorbing agent foam aluminum alloy substrate is used as a wave absorbing material sample for electromagnetic wave reflectivity testing, and the reflectivity in the Ka band (electromagnetic waves with a frequency range of 26.5 ~ 40GHz) is tested.

The CfBa curve in Figure 3 is the microwave-reflectivity curve of the barium titanate absorber foam aluminum alloy-based absorbing material, and its absorbing efficiency only reaches -3dB.

Example 4:

The foamed aluminum alloy with an appearance size of 80 mm × 80 mm, a relative density of 0.148 to 0.185, and an average pore diameter of 6 to 7 mm is used as the substrate, and the surface pretreatment method of the foamed aluminum alloy substrate is the same as in Example 1.

Take 20g of Ni-Zn ferrite wave absorbing agent as filler for wave absorbing coating, add titanate coupling agent JN-644 into Ni-Zn ferrite wave absorbing agent, the dosage of coupling agent JN-644 is 0.6g , then add the diluent of 5ml, diluent is n-butanol: xylene: propylene glycol methyl ether = 6: 4: 1 mixed solution, stir 30min with the speed of 10000r/min in the high-shear force dispersing emulsifier.

Dilute 0.4g of dispersant T70 with 5ml of diluent (mixture of n-butanol: xylene: propylene glycol methyl ether = 6:4:1), pour into the pretreated wave absorber filler and mix in a glass mortar Grinding completes the dispersion of wave absorber fillers.

The binder 6101 epoxy resin and curing agent polyamide were mixed in a mass ratio of 2:1, and the dosage of 6101 epoxy resin was 8.25g to prepare a film-forming substance.

Mix the prepared film-forming material and the dispersed Ni-Zn ferrite barium absorber filler and grind for 5 minutes, then stir for 10 minutes with a FA25 high-shear dispersing emulsifier at a speed of 10000r/min; Cleaner, under the condition of frequency 40KHz, disperse by ultrasonic oscillation for 20min; continue to disperse with FA25 high-shear dispersing emulsifier at a speed of 10000r/min for 10min; finally, sieve the coating with a 120-mesh sieve to prepare Ni-Zn Ferrite absorbing paint.

Use the JD-2025B air compressor and the W-71G spray gun with a diameter of 1.5mm as the air spraying equipment, and spray the prepared Ni-Zn ferrite wave-absorbing coating on the foamed aluminum alloy with surface pretreatment in the fume hood On the substrate, the spray amount is 20g. The foamed aluminum alloy substrate after spraying was placed in a 101-1 blast dryer for curing, the curing temperature was 60°C, and the curing time was 1 h.

After spraying and curing, the Ni-Zn ferrite absorber foam aluminum alloy substrate is used as the absorbing material sample for the electromagnetic wave reflectivity test, and the reflectivity in the Ka band (electromagnetic wave with a frequency range of 26.5 ~ 40GHz) is tested. .

The CfFe curve in Figure 3 is the microwave-reflectivity curve of the Ni-Zn ferrite absorber foam aluminum alloy-based absorbing material, and its absorbing efficiency reaches -9.5dB.

Example 5:

The foamed aluminum alloy with an appearance size of 80 mm × 80 mm, a relative density of 0.148 to 0.185, and an average pore diameter of 6 to 7 mm is used as the substrate, and the surface pretreatment method of the foamed aluminum alloy substrate is the same as in Example 1.

Take 20g carbonyl nickel wave absorbing agent as filler for wave absorbing paint, add silane coupling agent KH-550 to the carbonyl nickel wave absorbing agent, the amount of coupling agent KH-550 is 0.6g, then add 5ml diluent, diluent It is a mixed solution of n-butanol: xylene: propylene glycol methyl ether = 6:4:1, and it is stirred for 30 minutes at a speed of 10000 r/min in a high-shear force dispersing emulsifier.

Dilute 0.4g of dispersant B401 with 5ml of diluent (mixture of n-butanol: xylene: propylene glycol methyl ether = 6:4:1), pour into the pretreated wave absorber filler and mix in a glass mortar Grinding completes the dispersion of wave absorber fillers.

The binder 6101 epoxy resin and curing agent polyamide were mixed in a mass ratio of 2:1, and the dosage of 6101 epoxy resin was 8.25g to prepare a film-forming substance.

Mix the prepared film-forming material and the dispersed nickel-barium carbonyl wave absorbing agent filler and grind for 5 minutes, then stir for 10 minutes with a FA25 high-shear dispersing emulsifier at a speed of 10,000 r/min; Under the condition of frequency 40KHz, disperse by ultrasonic oscillation for 20min; continue to disperse with FA25 high-shear dispersing emulsifier at a speed of 10000r/min for 10min; finally, sieve the coating with a 120-mesh sieve to prepare nickel carbonyl absorbing coating.

Using the JD-2025B air compressor and the W-71G spray gun with a diameter of 1.5mm as the air spraying equipment, spray the prepared nickel carbonyl wave-absorbing coating on the foamed aluminum alloy substrate with surface pretreatment in the fume hood, and spray The amount is 20g. The foamed aluminum alloy substrate after spraying was placed in a 101-1 blast dryer for curing, the curing temperature was 60°C, and the curing time was 1 h.

After spraying and curing, the nickel carbonyl absorber foam aluminum alloy substrate is used as a sample of absorbing material for electromagnetic wave reflectivity testing, and the reflectivity in the Ka band (electromagnetic waves with a frequency range of 26.5-40GHz) is tested.

The CfNi curve in Figure 3 is the microwave-reflectivity curve of the carbonyl nickel absorber foam aluminum alloy-based absorbing material. The absorbing performance is good, up to -11.5dB, and the bandwidth below -10dB reaches 2.6GHz.

Embodiment 6:

The foamed aluminum alloy with an appearance size of 80 mm × 80 mm, a relative density of 0.148 to 0.185, and an average pore diameter of 6 to 7 mm is used as the substrate, and the surface pretreatment method of the foamed aluminum alloy substrate is the same as in Example 1.

Take 30g of Ni-Zn ferrite wave absorbing agent as filler for wave absorbing coating, add JN-115 titanate coupling agent to Ni-Zn ferrite wave absorbing agent, the amount of coupling agent JN-115 is 0.9g , with 400ml of absolute ethanol as the medium, put them together into a 2-liter ball mill tank and ball mill for wet mixing for 30 minutes, then add 20 g of nickel carbonyl wave absorbing agent into the ball mill tank, and ball mill for 5 hours; then dry the wet-mixed materials , remove the absolute ethanol, put it into a ball mill jar and dry mix it for 5 hours to prepare a Ni-Zn ferrite-nickel carbonyl composite wave absorbing agent filler.

Add 1.5g of silane coupling agent KH-550 to the Ni-Zn ferrite-nickel carbonyl composite wave absorbing agent filler, and then add 12.5ml of diluent (the diluent is n-butanol:xylene:propylene glycol methyl ether=6 : 4: 1 mixed solution), stirred for 30min at a speed of 10000r/min in a high-shear force dispersing emulsifier.

Dilute 1.0g of dispersant 963 with 12.5ml of diluent (the diluent is a mixture of n-butanol: xylene: propylene glycol methyl ether = 6:4:1), and pour it into the pretreated Ni-Zn ferrite- The nickel carbonyl composite wave-absorbing agent filler is mixed and ground in a glass mortar to complete the dispersion of the composite wave-absorbing agent filler.

The binder 6101 epoxy resin and curing agent polyamide were mixed in a mass ratio of 2:1, and the dosage of 6101 epoxy resin was 22g to prepare a film-forming substance.

Mix the prepared film-forming material with the dispersed Ni-Zn ferrite-nickel carbonyl composite barium absorber filler and grind for 5 minutes, then stir for 10 minutes with a FA25 high-shear dispersing emulsifier at a speed of 10000r/min; KQ-100 ultrasonic cleaner, under the condition of frequency 40KHz, disperse by ultrasonic oscillation for 20min; continue to disperse with FA25 high-shear dispersing emulsifier at a speed of 10000r/min for 10min; finally, sieve the coating with a 120-mesh sieve to prepare Form Ni-Zn ferrite-nickel carbonyl composite absorbing coating.

Use the JD-2025B air compressor and the W-71G spray gun with a diameter of 1.5mm as the air spraying equipment, spray the prepared Ni-Zn ferrite-nickel carbonyl composite absorbing coating on the surface pretreatment in the fume hood On the foamed aluminum alloy substrate, the spraying amount is 20g. The foamed aluminum alloy substrate after spraying was placed in a 101-1 blast dryer for curing, the curing temperature was 60°C, and the curing time was 1 h.

After spraying and curing, the Ni-Zn ferrite-nickel carbonyl composite absorber foam aluminum alloy matrix is used as the absorbing material sample for the electromagnetic wave reflectivity test. ) reflectivity.

Figure 4 is the microwave-reflectivity curve of the Ni-Zn ferrite-nickel carbonyl composite absorber foam aluminum alloy-based absorbing material. Its absorbing performance is better, up to -16dB, and the bandwidth below -10dB 7GHz.

Embodiment 7:

The foamed aluminum alloy with an appearance size of 80 mm × 80 mm, a relative density of 0.178 to 0.185, and an average pore diameter of 6 to 7 mm is used as the substrate, and the surface pretreatment method of the foamed aluminum alloy substrate is the same as in Example 1.

Take 20g carbonyl nickel wave absorbing agent as filler for wave absorbing paint, add KH-550 silane coupling agent to the carbonyl nickel wave absorbing agent, the amount of coupling agent KH-550 is 0.6g, use 400ml absolute ethanol as the medium, together Put it into a 2-liter ball mill tank and mix it wet for 30 minutes, then add 10 g of polyaniline wave absorbing agent into the ball mill tank, and mill it wet for 5 hours; then dry the wet-mixed material, remove absolute ethanol, and put it into the ball mill tank The medium ball mill was dry mixed for 5 hours to prepare the nickel carbonyl-polyaniline composite wave absorbing agent filler.

Add 0.9g of silane coupling agent KH-550 to the nickel carbonyl-polyaniline composite wave absorbing agent filler, and then add 7.5ml of diluent (the diluent is n-butanol:xylene:propylene glycol methyl ether=6:4:1 Mixed solution) was stirred for 30min at a speed of 10000r/min in a high shear force dispersing emulsifier.

Dilute 0.6g of dispersant B402 with 7.5ml of diluent (the diluent is a mixture of n-butanol: xylene: propylene glycol methyl ether = 6:4:1), and pour it into the pretreated nickel carbonyl-polyaniline composite absorbent The wave agent filler is mixed and ground in a glass mortar to complete the dispersion of the composite wave absorber filler.

The binder 6101 epoxy resin and the curing agent polyamide were mixed in a mass ratio of 2:1, and the amount of 6101 epoxy resin was 12.85g to prepare a film-forming substance.

Mix the prepared film-forming material with the dispersed nickel carbonyl-polyaniline composite barium wave absorbing agent filler, grind for 5 minutes, and then stir for 10 minutes with a FA25 high-shear dispersing emulsifier at a speed of 10000r/min; Cleaner, under the condition of frequency 40KHz, disperse by ultrasonic oscillation for 20min; continue to disperse with FA25 high-shear dispersing emulsifier at a speed of 10000r/min for 10min; finally, sieve the coating with a 120-mesh screen to prepare nickel carbonyl- Polyaniline composite absorbing coating.

Using the JD-2025B air compressor and the W-71G spray gun with a diameter of 1.5mm as the air spraying equipment, spray the prepared nickel carbonyl-polyaniline composite wave-absorbing coating on the foamed aluminum alloy with surface pretreatment in the fume hood On the substrate, the spray amount is 20g. The foamed aluminum alloy substrate after spraying was placed in a 101-1 blast dryer for curing, the curing temperature was 60°C, and the curing time was 1 h.

After spraying and curing, the nickel carbonyl-polyaniline composite absorber foam aluminum alloy substrate is used as the absorbing material sample for the electromagnetic wave reflectivity test, and the reflectivity in the Ka band (electromagnetic wave with a frequency range of 26.5 ~ 40GHz) is tested. .

Figure 5 is the microwave-reflectivity curve of nickel carbonyl-polyaniline composite absorber foam aluminum alloy-based absorbing material, the bandwidth below -10dB reaches 3.18GHz, and the absorbing efficiency reaches -13.03dB.

Claims (8)

1, a kind of preparation method of foam aluminum alloy base wave-absorbing material, comprise the surface preparation of foam aluminium alloy material, the preparation of wave absorbing agent coating and the spraying step of foam aluminium alloy material, it is characterized in that: with the foam aluminium alloy material through ungrease treatment and blasting treatment is matrix, at single antiradar coatings of its surface-coated or composite wave-absorbing coating, be prepared into single wave absorbing agent foam aluminum alloy base wave-absorbing material or composite wave-absorbing agent foam aluminum alloy base wave-absorbing material.

2, the preparation method of a kind of foam aluminum alloy base wave-absorbing material of narrating according to claim 1, it is characterized in that the surperficial ungrease treatment of foam aluminium alloy material: be that 0.148～0.185 foam aluminium alloy is as the foam aluminium alloy sill with relative density, at first wash away the foam aluminium alloy material with room temperature cold water, utilize high-pressure injection alkali lye to clean the foam aluminium alloy material surface then, alkali liquid temperature need be controlled at 60 ± 3 ℃; Clean 15min, deionized water hydro-peening foam aluminium alloy material surface through room temperature cold water flush, ultrasonic wave then, to remove residual alkali lye; Dry up the foam aluminium alloy material with hair dryer again, then 100 ℃ of oven dry down.

3, the preparation method of a kind of foam aluminum alloy base wave-absorbing material of narrating according to claim 1, the surface sand-blasting that it is characterized in that the foam aluminium alloy material is handled: carry out the particulate sandblast with wet abrasive blasting machine, wherein quartzy sand grains diameter is less than 100 μ m, compressed air source 3.0～7.0kg/cm ², the about 100～150mm of command range in the sandblast.

4, a kind of foam aluminium alloy of narrating according to claim 1 is inhaled the first-harmonic preparation methods, it is characterized in that the preparation of single wave absorbing agent coating: the wave absorbing agent filler is carried out carrying out coupling processing with coupling agent, the coupling agent consumption is 3% of a wave absorbing agent filler, add dispersant then through the diluent dilution, dispersant dosage is 2% of a wave absorbing agent filler, ground and mixed in glass mortar; Then the film forming matter for preparing is added the wave absorbing agent filler through disperseing, the binding agent consumption is 30% of binding agent and a wave absorbing agent filler total amount in the film forming matter, ground and mixed in glass mortar; With the speed stirring 10min of high-shearing dispersion emulsifying machine, disperse 20min then, again with the speed stirring 10min of high-shearing dispersion emulsifying machine with 10000r/min with ultrasonic cleaner supersonic oscillations under the condition of frequency 40KHz with 10000r/min; Sieve with 120 eye mesh screens at last.

5, the preparation method of a kind of foam aluminum alloy base wave-absorbing material of narrating according to claim 1, it is characterized in that the preparation of composite wave-absorbing agent coating: a kind of wave absorbing agent filler that mass percent composition in two kinds of wave absorbing agent fillers is high carries out coupling processing with coupling agent, 3% of coupling agent consumption wave absorbing agent filler, with absolute ethyl alcohol is medium, in ball mill with the speed ball milling wet mixing 30min of 120r/min, then the wave absorbing agent filler that the mass percent composition is low in two kinds of wave absorbing agent fillers is joined in the ball mill, speed ball milling wet mixing 5h with 120r/min, again the drying materials after the wet mixing is removed ethanol, put into ball mill and do mixed 5h with the speed ball milling of 120r/min; Material after do mixing is as composite wave-absorbing agent filler, prepares composite wave-absorbing agent coating by the method for claim 4.

6, the preparation method of the wave absorbing agent coating of narrating according to claim 4, it is characterized in that described dispersant: dispersant is dispersant B 401, B402, CH-10S, CH-13F, CH-13, T70 or 963.

7, the preparation method of the wave absorbing agent coating of narrating according to claim 4, it is characterized in that described coupling agent: coupling agent is silane coupler or titanate coupling agent.

8, the preparation method of the wave absorbing agent coating of narrating according to claim 4, it is characterized in that described film forming matter: film forming matter is that epoxy resin of binder mixes by mass ratio with the curing agent polyamide at 2: 1.

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