Light heat-insulation electromagnetic wave absorption and high-energy protection integrated coating and preparation method thereof

Abstract

The invention relates to the technical field of electromagnetic wave absorption materials, and provides a light heat-insulation electromagnetic wave absorption and high-energy protection integrated coating and a preparation method thereof.The coating is formed by compounding carbonyl iron (CIP), cavity (Air) and zirconium oxide (ZrO2) heterostructure powder and silicate high-temperature-resistant glue, a hollow gradient structure is constructed through a sol-gel method and a hydrothermal etching process, and the hollow gradient structure is formed through a high-temperature-resistant coating. The coating is prepared on the surface of an aluminum alloy substrate by combining a brush coating curing technology. The coating achieves electromagnetic parameter gradient matching and thermal-optical performance coupling optimization through cavity design and ceramic shell layer coordinated regulation and control, and meanwhile has the characteristics of low density and low thermal conductivity. The integrated design solves the problem of thermal stress mismatch of a traditional multi-layer coating interface, and the comprehensive protection efficiency and the operation stability of industrial laser equipment and a high-temperature hot end device in a complex electromagnetic and high-energy environment are remarkably improved.

Description

Technical Field

[0001] The present invention specifically relates to a lightweight heat-insulating electromagnetic wave absorbing and high-energy protective integrated coating and a preparation method thereof, and belongs to the technical field of electromagnetic wave absorbing materials. Background Art

[0002] With the rapid development of electronic information technology, electromagnetic radiation interference on industrial equipment has become increasingly prominent. Improving the electromagnetic wave absorption performance of protective coatings on equipment surfaces is one of the core technologies for achieving electromagnetic interference resistance and ensuring stable operation. Furthermore, for industrial laser equipment (such as laser rangefinders and melt pool monitoring systems) and glass manufacturing hot-end equipment operating under high-intensity energy, there is an urgent need to combine high-energy protection capabilities with efficient electromagnetic wave absorption. Specifically, by manipulating the electromagnetic parameters of industrial equipment surface coating materials and implementing appropriate structural designs, the coating's absorption capacity for specific electromagnetic wave bands can be enhanced, protecting the production control system from electromagnetic interference and significantly improving the equipment's overall electromagnetic protection performance. Furthermore, by combining the design and control of the surface coating's light reflectivity and thermal insulation properties, the risk of damage to industrial equipment caused by extreme environments such as high temperatures caused by high-energy beam loading can be significantly reduced. Traditional approaches employ separate application of the absorber layer and the high-energy protective coating. For example, previous work has employed a three-layer structure consisting of a cracking absorber layer, a heat dissipation layer, and a thermal insulation layer. However, this resulting interfacial thermal stress mismatch can lead to delamination between the layers. In addition, the increase in thickness and weight caused by multi-layer coating makes it difficult to meet the demand for lightweighting of industrial equipment. Therefore, the present invention proposes to use highly reflective ceramic materials to modify the surface of traditional absorbing materials carbonyl iron (CIP) particles, and construct lightweight hollow heterostructures using sol-gel and solvothermal methods. On the one hand, combined with the design of the gradient distribution of electromagnetic parameters and the precise control of the thickness of the hollow shell, while greatly improving the electromagnetic wave absorption performance, the synergistic optimization of impedance matching and laser energy dispersion in the millimeter wave band is achieved. On the other hand, the high reflectivity and low thermal conductivity of the surface ceramic are used to reduce the risk of laser and thermal damage. In addition, the designed hollow heterostructure can achieve overall weight reduction due to its low density characteristics, and combine interface phonon scattering to suppress local heat accumulation, and further reduce the thermal conductivity of the material system through the air barrier effect, thereby establishing a coupling mechanism between electromagnetic wave absorption, high-energy protection and lightweight performance. This technology is not only suitable for extreme industrial environments, but its lightweight design can also provide an efficient solution for mobile industrial detection equipment and advanced equipment requiring multi-spectrum compatible protection. Summary of the Invention

[0003] The purpose of the present invention is to provide a lightweight thermal insulation electromagnetic wave absorption and high-energy protection integrated coating and its preparation method. A zirconium oxide (ZrO2) shell layer is superimposed and coated on the surface of a silicon oxide (SiO2) shell layer by a sol-gel method. Subsequently, the SiO2 shell layer is removed by a hydrothermal method, and CIP@Air@ZrO2 powder is obtained by high-temperature calcination. The prepared powder is evenly mixed with a silicate high-temperature resistant glue, and a coating is prepared on an aluminum alloy substrate by a brushing process, and the coating is cured at a certain temperature. The raw materials for preparation mainly include: carbonyl iron (CIP), tetraethyl silicate (TEOS), ammonia water (NH3·H2O), γ-aminopropyltriethoxysilane (KH550), zirconium n-propoxide (C 12 H 28 O4Zr), sodium hydroxide (NaOH) and silicate high temperature resistant glue, etc.

[0004] The specific technical solutions of the present invention are as follows:

[0005] Step 1. Add 1-2g of CIP to 5-20mL of water, 0.5-2mL of KH550, and 200-500mL of alcohol, stir mechanically for 1-3h, and add 5-20mL of NH3·H2O to adjust the pH. Subsequently, use a peristaltic pump to dropwise add 50-150mL of alcohol solution containing 0.25-2mL of TEOS (peristaltic pump speed is 20-60r / min), and continue mechanical stirring at 30-50℃ for 10-24h (mechanical stirring speed is 200-600r / min). After stirring, separate and dry by magnetic separation to obtain CIP@SiO2 powder.

[0006] Step 2. Add the CIP@SiO2 powder obtained in step 1 to 200-500 mL of alcohol and use a peristaltic pump to add 0.25-1.5 mL of C 12 H 28 Add 50-150mL of alcohol solution of O4Zr (peristaltic pump speed is 20-60r / min), and continue mechanical stirring for 12-24h (mechanical stirring speed is 200-600r / min). After aging at room temperature for 12-36h, wash with alcohol and separate for later use. If CIP@SiO2@ZrO2 powder is to be obtained directly, it needs to be sintered to 500-600℃ in a nitrogen atmosphere, with a heating rate of 2-5℃ / min, kept warm for 1-5h, and then cooled with the furnace;

[0007] Step 3. Add 100-300 mL of 0.6-1.2 mol / L NaOH solution to the powder obtained in step 2 and mechanically stir at 45-65°C for 18-48 hours (mechanical stirring speed is 200-600 r / min). After drying, sinter the powder to 500-600°C in a nitrogen atmosphere at a heating rate of 2-5°C / min, hold the temperature for 1-5 hours, and then cool the furnace to obtain CIP@Air@ZrO2 powder.

[0008] Step 4. The powder prepared according to the above steps 1 to 3 is evenly mixed with the silicate high temperature resistant glue in a ratio of 0.5 to 2:1, and a coating is formed by brushing. After standing in a constant temperature and humidity chamber for 24 to 48 hours, it is placed in a blast drying oven for further curing. The curing process is set to 60°C / 8 to 14 hours → 70 to 80°C / 6 to 8 hours → 100 to 120°C / 1 to 4 hours.

[0009] Beneficial effects:

[0010] (1) The prepared lightweight thermal insulation multifunctional powder has good uniformity and does not affect the intrinsic phase structure of CIP;

[0011] (2) The prepared lightweight, heat-insulating, multifunctional powder has excellent electromagnetic wave absorption capability and high reflectivity in the working spectrum band of industrial equipment;

[0012] (3) The density of the prepared lightweight thermal insulation multifunctional powder is significantly lower than that before modification, and the surface density of the coating obtained after curing is low;

[0013] (4) The prepared coating has good thermal insulation performance and can effectively reduce heat transfer;

[0014] (5) The present invention optimizes the filler / base material ratio and the binder ratio, applies an integrated coating to the substrate surface via a brushing process, and cures the coating under certain temperature and humidity conditions. The method of the present invention has significant advantages such as simple process, easy control, and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the microscopic morphology of the carbonyl iron@cavity@zirconia powder prepared in Example 1.

[0016] Figure 2 Phase diagram of the four powders prepared in Example 1.

[0017] Figure 3 This is the true density diagram of the four powders prepared in Example 1.

[0018] Figure 4 This is a comparison chart of the microwave absorption performance of the carbonyl iron powder before and after modification in Example 1.

[0019] Figure 5 This is a reflection performance diagram of the powder prepared in Example 1.

[0020] Figure 6 This is a diagram of the thermal insulation performance of the carbonyl iron@cavity@zirconia coating prepared in Example 1.

[0021] Figure 7 This is the microscopic morphology of the carbonyl iron@silicon oxide@zirconia powder prepared in Example 2.

[0022] Figure 8 This is the true density diagram of the four powders prepared in Example 2.

[0023] Figure 9 This is a reflection performance diagram of the carbonyl iron@cavity@zirconia powder prepared in Example 2.

[0024] Figure 10 This is the microscopic morphology of the carbonyl iron@cavity@zirconia powder prepared in Example 3.

[0025] Figure 11 This is a comparison chart of the microwave absorption performance of the carbonyl iron powder before and after modification in Example 3. DETAILED DESCRIPTION

[0026] The present invention will be further described below with reference to specific examples. The methods described are conventional methods unless otherwise specified, and the raw materials described can be obtained from public commercial channels unless otherwise specified.

[0027] The following description sets forth numerous relevant technical details to facilitate a thorough understanding of the present invention. However, the present invention may also be implemented using other technical approaches different from those described herein, and those skilled in the art may make similar generalizations without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0028] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive of other embodiments.

[0029] Example 1

[0030] A lightweight thermal insulation electromagnetic wave absorption and high-energy protection integrated coating and a preparation method thereof, the specific steps are as follows:

[0031] Step 1. 1g of CIP was added to 10mL of water, 1mL of KH550, and 200mL of alcohol. The mixture was mechanically stirred for 2h, and 5mL of NH3·H2O was added to adjust the pH. Subsequently, a peristaltic pump was used to dropwise add 0.5mL of TEOS in 50mL of alcohol solution (at a speed of 60r / min). Mechanical stirring was continued at 40°C for 10h (at a speed of 350r / min). After stirring, the mixture was separated and dried by magnetic separation to obtain CIP@SiO2 powder.

[0032] Step 2. Add 200 mL of alcohol to the CIP@SiO2 powder obtained in step 1, and use a peristaltic pump to add 1 mL of C 12 H 28 Prepare a 100mL alcohol solution of O4Zr (peristaltic pump speed at 20r / min), continuously stir mechanically for 12h (mechanical stirring speed at 350r / min), age at room temperature for 12h, and then wash with alcohol for separation. To directly obtain CIP@SiO2@ZrO2 powder, sinter it to 550℃ in a nitrogen atmosphere at a heating rate of 3℃ / min and a holding time of 2h, followed by furnace cooling.

[0033] Step 3. Add 100 mL of 0.8 mol / L NaOH solution to the powder obtained in Step 2 and mechanically stir at 55°C for 24 hours (at a speed of 350 rpm). After drying, sinter the mixture to 550°C in a nitrogen atmosphere at a heating rate of 3°C / min. Hold the mixture for 2 hours and then cool it in the furnace to obtain CIP@Air@ZrO2 powder.

[0034] Step 4. The powder prepared in steps 1 to 3 is evenly mixed with the silicate high-temperature resistant glue in a ratio of 1:1, and a coating is formed by brushing. After standing in a constant temperature and humidity chamber for 48 hours, it is placed in a forced air drying oven for further curing. The curing process is set to 60°C / 12h→80°C / 8h→100°C / 2h.

[0035] The microscopic morphologies of the four powders are as follows Figure 1 As shown, the existence of the cavity can be clearly seen. Figure 2 The phase diagram of the powder shows that the coating modification does not affect the phase structure of the CIP itself. Figure 3 As shown in Figure 2, the true density of the powder decreased significantly to 6.02 g / cm after modification. 3 , which is 20.89% lower than the original powder. Figure 4 As shown in the figure, the minimum reflection loss of the modified powder is -60.64dB, which completely covers the 8-12GHz band and the effective absorption bandwidth remains almost unchanged. Figure 5As shown in the figure, the reflectivity in the near infrared band is increased by nearly 40%, showing a high reflective performance. The thermal insulation performance of the coating is as follows Figure 6 As shown, it can be seen that the coating has excellent thermal insulation performance, can effectively block heat transfer, and significantly reduce the surface temperature of industrial equipment.

[0036] Example 2

[0037] A lightweight heat-insulating electromagnetic wave absorbing and high-energy protective integrated coating and a preparation method thereof, comprising the following steps:

[0038] Step 1. Add 1g of CIP to 10mL of water, 1mL of KH550, and 200mL of alcohol, stir mechanically for 3h, and add 10mL of NH3·H2O to adjust the pH. Subsequently, use a peristaltic pump to add 0.5mL of TEOS in 100mL of alcohol dropwise (at a peristaltic pump speed of 20r / min). Mechanical stirring is continued at 40°C for 14h (at a mechanical stirring speed of 350r / min). After stirring, the mixture is separated and dried by magnetic separation to obtain CIP@SiO2 powder.

[0039] Step 2. Add 200 mL of alcohol to the CIP@SiO2 powder obtained in step 1, and use a peristaltic pump to add 0.5 mL of C 12 H 28 A 100mL alcohol solution of O4Zr (peristaltic pump speed at 20r / min) was mechanically stirred for 16h (mechanical stirring speed at 350r / min), aged at room temperature for 24h, washed with alcohol, and separated for later use. To directly obtain CIP@SiO2@ZrO2 powder, it was sintered to 550℃ in a nitrogen atmosphere at a heating rate of 3℃ / min and a holding time of 2h, followed by furnace cooling.

[0040] Step 3. Add 100 mL of 1 mol / L NaOH solution to the powder obtained in Step 2 and mechanically stir at 55°C for 24 hours (at a speed of 350 rpm). After drying, sinter the powder in a nitrogen atmosphere to 550°C at a heating rate of 3°C / min. Hold the temperature for 2 hours and then cool the mixture to obtain CIP@Air@ZrO2 powder.

[0041] Step 4: Mix the powder prepared in steps 1 to 3 above with the silicate high-temperature resistant glue in a ratio of 1:1, make a coating by brushing, and place it in a constant temperature and humidity chamber for 48 hours, and place it in a forced air drying oven for further curing. The curing process is set to 60℃ / 12h→80℃ / 8h→100℃ / 2h.

[0042] The powder coated with SiO2 and ZrO2 is as follows Figure 7 As shown in the figure, we can see the obvious core-shell structure, and the shell is relatively thick. The density of the powder is as follows Figure 8 As shown in the figure, it can be seen that the true density of the powder decreased significantly after modification, and further decreased to 5.65 g / cm on the basis of Example 1. 3 , which is 25.76% lower than that of carbonyl iron powder. The reflectivity curve of the powder is as follows Figure 9 As shown in Figure 2, the reflectivity is improved in the near-infrared band.

[0043] Example 3

[0044] A lightweight heat-insulating electromagnetic wave absorbing and high-energy protective integrated coating and a preparation method thereof, comprising the following steps:

[0045] Step 1. Add 1g of CIP to 20mL of water, 1mL of KH550, and 200mL of alcohol, stir mechanically for 3h, and add 10mL of NH3·H2O to adjust the pH. Subsequently, use a peristaltic pump to add 1mL of TEOS in 100mL of alcohol solution dropwise (peristaltic pump speed is 20r / min). Stir continuously at 40℃ for 24h (mechanical stirring speed is 350r / min). After stirring, separate and dry by magnetic separation to obtain CIP@SiO2 powder.

[0046] Step 2. Add 200 mL of alcohol to the CIP@SiO2 powder obtained in step 1, and use a peristaltic pump to add 1 mL of C 12 H 28 Prepare a 100mL alcohol solution of O4Zr (peristaltic pump speed at 20r / min) and continue mechanical stirring for 12h (mechanical stirring speed at 350r / min). Aging at room temperature for 24h, washing with alcohol and setting aside. To directly obtain CIP@SiO2@ZrO2 powder, sinter it to 550℃ in a nitrogen atmosphere, heating rate of 3℃ / min, holding time for 2h, and then cool it in the furnace.

[0047] Step 3. Add 100 mL of 1 mol / l NaOH solution to the powder obtained in step 2, mechanically stir at 55 ° C for 24 h (mechanical stirring speed is 350 r / min), sinter to 550 ° C in a nitrogen atmosphere at a heating rate of 3 ° C / min, keep warm for 2 h, and then cool in the furnace to finally obtain CIP@Air@ZrO2 powder.

[0048] Step 4: Mix the powder prepared in steps 1 to 3 above with the silicate high-temperature resistant glue in a ratio of 1:1, make a coating by brushing, and place it in a constant temperature and humidity chamber for 36 hours, and place it in a forced air drying oven for further curing. The curing process is set to 60℃ / 10h→80℃ / 8h→100℃ / 2h.

[0049] The final powder surface morphology is as follows Figure 10As shown, it can be seen that the surface particles are coarse and completely cover the original CIP surface particles without any cavity morphology. The microwave absorption performance of the powder is as follows Figure 11 As shown, the wave absorbing effect of the sample in this embodiment is greatly reduced.

[0050] The above specific description further illustrates the purpose, technical solutions and beneficial effects of the invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A lightweight thermal insulation electromagnetic wave absorption and high-energy protection integrated coating and its preparation method, characterized by: Through modified A SiO2 shell is coated on the surface of carbonyl iron (CIP) using a sol-gel method. A zirconium oxide (ZrO2) shell is then superimposed on the surface of the silicon oxide (SiO2) shell using a sol-gel method. The SiO2 shell is then removed hydrothermally to form a cavity (Air), which is then calcined at high temperature to obtain a CIP@Air@ZrO2 powder. The prepared powder is then uniformly mixed with a high-temperature silicate adhesive and coated on an aluminum alloy substrate using a brushing process, where it solidifies at a specific temperature.

2. A lightweight thermal insulation, electromagnetic wave absorption and high-energy protection integrated coating and a preparation method thereof as claimed in claim 1, characterized in that: The preparation method is as follows. Step 1. Carbonyl iron (CIP), tetraethyl silicate (TEOS), ammonia (NH3·H2O), γ-aminopropyltriethoxysilane (KH550), zirconium n-propoxide (C 12 H 28 Using O4Zr and sodium hydroxide (NaOH) as raw materials, the shell is synthesized via a sol-gel method, and the cavity is prepared using a hydrothermal method. The powder material is finally prepared by high-temperature sintering in an atmosphere tube furnace. Step 2. Use silicate glue as a high-temperature resistant binder and mix it evenly with the powder. The mass ratio is controlled between 0.5 and 2:1 to ensure that the powder and the binder are evenly mixed. Step 3. Perform a coating process on the aluminum alloy substrate, solidify the coating after preparation, and place the sample in a constant temperature and humidity chamber.

3. A process for preparing the powder according to claim 2, characterized in that: The preparation steps are as follows. Step 1. Add 1-2g of CIP to 5-20mL of water, 0.5-2mL of KH550, and 200-500mL of alcohol, stir mechanically for 1-3h, and add 5-20mL of NH3·H2O to adjust the pH. Subsequently, use a peristaltic pump to dropwise add 50-150mL of an alcohol solution containing 0.25-2mL of TEOS (at a peristaltic pump speed of 20-60r / min) and continue mechanical stirring at 30-50°C for 10-24h (at a mechanical stirring speed of 200-600r / min). After stirring, separate and dry the mixture by magnetic separation to obtain CIP@SiO2 powder. Step 2. Add 200-500 mL of alcohol to the CIP@SiO2 powder obtained in step 1, and use a peristaltic pump to add 0.25-1.5 mL of C 12 H 28 Add 50-150mL of alcohol solution of O4Zr (peristaltic pump speed is 20-60r / min), and continue mechanical stirring for 12-24h (mechanical stirring speed is 200-600r / min). After aging at room temperature for 12-36h, wash with alcohol and separate for later use. If CIP@SiO2@ZrO2 powder is to be obtained directly, it needs to be sintered to 500-600℃ in a nitrogen atmosphere, with a heating rate of 2-5℃ / min, kept warm for 1-5h, and then cooled with the furnace; Step 3. Add 100-300 mL of 0.6-1.2 mol / L NaOH solution to the powder obtained in Step 2 and mechanically stir at 45-65°C for 18-48 hours (at a mechanical stirring speed of 200-600 rpm). After drying, sinter the powder to 500-600°C in a nitrogen atmosphere at a heating rate of 2-5°C / min. Hold the temperature for 1-5 hours and then cool the mixture in the furnace to obtain CIP@Air@ZrO2 powder.

4. A lightweight thermal insulation, electromagnetic wave absorption and high-energy protection integrated coating and a preparation method thereof as claimed in claim 2, characterized in that: The preparation steps are as follows. The powder prepared according to steps 1 to 3 above is evenly mixed with the silicate high-temperature resistant glue in a ratio of 0.5 to 2:1, and a coating is formed by brushing. After standing in a constant temperature and humidity chamber for 24 to 48 hours, it is placed in a forced air drying oven for further curing. The curing process is set to 60°C / 8 to 14 hours → 70 to 80°C / 6 to 8 hours → 100 to 120°C / 1 to 4 hours.

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