Preparation method for in-situ synthesis of microparticle reinforced thermal control functional film layer on surface of 7B04 aluminum alloy

Abstract

A preparation method of a 7B04 aluminum alloy surface in-situ synthesis microparticle enhanced thermal control function film layer can effectively improve the density of the film layer, meanwhile, the film layer is high in infrared emissivity and good in thermal control function, and comprises the steps that firstly, the 7B04 aluminum alloy surface, copper oxide and chromic oxide are pretreated, then a micro-arc oxidation electrolyte is prepared, and the 7B04 aluminum alloy surface is subjected to in-situ synthesis; the pretreated 7B04 aluminum alloy is placed in a stainless steel electrolytic cell of micro-arc oxidation equipment, then the micro-arc oxidation electrolyte is added into the stainless steel electrolytic cell, micro-arc oxidation treatment is conducted on the aluminum alloy through a micro-arc oxidation power source, the electrolyte is continuously stirred in the oxidation treatment process, and the aluminum alloy is subjected to micro-arc oxidation treatment; and finally, obtaining an in-situ synthesized microparticle reinforced thermal control functional film layer on the surface of the 7B04 aluminum alloy, washing the film layer with deionized water, and naturally airing the film layer to obtain the 7B04 aluminum alloy. The composition of the micro-arc oxidation electrolyte is designed, in the growth process of a micro-arc oxidation film layer, copper chromite black particles are synthesized in situ through chemical reaction, the particles and the film layer are metallurgically bonded, and the method has actual application and popularization value.

Description

Technical Field

[0001] This invention relates to the field of surface treatment technology for metallic materials, specifically a method for preparing a microparticle-enhanced thermal control functional film layer synthesized in situ on the surface of 7B04 aluminum alloy. Background Technology

[0002] Micro-arc oxidation is an advanced surface treatment technology for preparing ceramic films on light metal surfaces, characterized by its simple process, high production efficiency, and wide applicability to various materials. Studies have shown that by adding solid particles or colloids of different properties to the micro-arc oxidation electrolyte, the structure and properties of the micro-arc oxidation film can be effectively controlled, while simultaneously endowing the film with special properties such as thermal control, catalysis, wear resistance, and friction reduction. However, during the micro-arc oxidation process, the added microparticles exhibit poor dispersibility, easily agglomerating and settling, which is detrimental to improving the coating's microstructure and microstructure properties. Furthermore, the added particles often bind to the film through mechanical interlocking, resulting in weak interfacial adhesion and a tendency to detach, leading to premature film failure.

[0003] In recent years, with the rapid development of my country's aerospace technology and industry, various spacecraft are becoming larger and more multifunctional, leading to increasingly higher requirements for the special functions of equipment surfaces (such as surface hardness and thermal control performance). 7B04 aluminum alloy, belonging to the Al-Zn-Mg-Cu system, is a heat-treatable aluminum alloy with high specific strength and good machinability. It is widely used in the manufacturing of aircraft, spacecraft, satellites, and their auxiliary equipment. Against this backdrop, there is an urgent need to develop a micro-arc oxidation film layer that combines excellent microstructure with thermal control functions to effectively improve the surface properties of 7B04 aluminum alloy and meet the actual needs of aerospace equipment. Summary of the Invention

[0004] In view of the above situation and to overcome the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing a micro-particle-enhanced thermal control functional film layer in situ synthesized on the surface of 7B04 aluminum alloy, which can effectively improve the film layer density, while the film layer has high infrared emissivity and good thermal control function.

[0005] To achieve the objective of this invention, the technical solution adopted is a method for preparing an in-situ synthesized microparticle-reinforced thermal control functional film layer on the surface of 7B04 aluminum alloy, which is achieved by the following steps: S1, Material Pretreatment S1.1, 7B04 aluminum alloy surface pretreatment: The 7B04 aluminum alloy is polished and rusted in sequence with 600#, 800#, 1000#, 1200# and 1500# metallographic sandpaper to remove surface oxides and oil stains. Then, it is ultrasonically treated at 40KHz for 15-30 minutes in anhydrous ethanol. Finally, the aluminum alloy surface is rinsed with deionized water and dried for later use. S1.2 Pretreatment of copper oxide and chromium oxide: Copper oxide and chromium oxide were ultrasonically cleaned in anhydrous ethanol for 20-40 min at 40 kHz, respectively. Then they were centrifuged in a centrifuge at 8000-10000 r / min for 15-30 min. After discarding the cleaning solution, the obtained copper oxide and chromium oxide were placed in a vacuum drying oven and dried at 80-130℃ for 1-3 h for later use. S2. Preparation of micro-arc oxidation electrolyte First, phosphate, borate, sodium hydroxide, and organic additives are added sequentially to deionized water and stirred thoroughly until completely dissolved. Then, copper oxide and chromium oxide are added and stirred until the solution is uniformly dispersed, thus preparing the micro-arc oxidation electrolyte of the multi-component system. The phosphate is sodium hexametaphosphate with a concentration of 30 g / L; the borate is sodium tetraborate with a concentration of 10 g / L; the organic additive is triethanolamine with a concentration of 5 ml / L; the sodium hydroxide concentration is 5 g / L; the concentration of the mixture of copper oxide and chromium oxide is 5–17 g / L, the mass ratio of copper oxide to chromium oxide is 1:2, and the particle size of both copper oxide and chromium oxide is 20–500 nm. S3. Preparation of functional film layers The pretreated 7B04 aluminum alloy was placed in the stainless steel electrolytic cell of the micro-arc oxidation equipment, with the 7B04 aluminum alloy as the anode and the stainless steel electrolytic cell as the cathode. The micro-arc oxidation electrolyte prepared in step S2 was added to the stainless steel electrolytic cell, and the aluminum alloy was subjected to micro-arc oxidation treatment using a micro-arc oxidation power supply. The micro-arc oxidation process parameters were: current: 8A / dm 2 The frequency was 300Hz, the duty cycle was 25%, and the electrolyte temperature was adjusted to 20-25℃ using a low-temperature constant temperature bath. The micro-arc oxidation treatment time was 20-50min. During the entire oxidation process, the electrolyte was continuously mechanically stirred at a speed of 1000-2000r / min. Finally, an in-situ synthesized microparticle-reinforced thermal control functional film was obtained on the surface of 7B04 aluminum alloy. The film was rinsed with deionized water and air-dried to obtain an in-situ synthesized microparticle-reinforced thermal control functional film with a thickness of 32-65μm on the surface of 7B04 aluminum alloy.

[0006] This invention designs the composition of the micro-arc oxidation electrolyte and synthesizes copper chromium black particles in situ through chemical reaction during the growth of the micro-arc oxidation film. The particles exhibit a metallurgical bond with the film, and the particles are uniformly dispersed in the film, which can effectively improve the film density. At the same time, the film has high infrared emissivity and good thermal control function. This invention is a major innovation in the field of metal material surface treatment technology and has practical application value. Attached Figure Description

[0007] Figure 1The XRD pattern of the microparticle-enhanced thermal control functional film layer synthesized in situ on the surface of 7B04 aluminum alloy according to the present invention; Figure 2 This is a macroscopic morphology image of the in-situ synthesized microparticle-enhanced thermal control functional film layer on the surface of 7B04 aluminum alloy prepared in Example 1 of the present invention. Figure 3 This is a macroscopic morphology image of the in-situ synthesized microparticle-enhanced thermal control functional film layer on the surface of 7B04 aluminum alloy prepared in Example 2 of the present invention. Figure 4 This is a macroscopic morphology image of the in-situ synthesized microparticle-enhanced thermal control functional film layer on the surface of 7B04 aluminum alloy prepared in Example 3 of the present invention. Figure 5 This is a SEM image of the in-situ synthesized microparticle-enhanced thermal control functional film layer on the surface of 7B04 aluminum alloy prepared in Example 1 of the present invention. Figure 6 This is a SEM image of the in-situ synthesized microparticle-enhanced thermal control functional film layer on the surface of 7B04 aluminum alloy prepared in Example 2 of the present invention. Figure 7 This is a SEM image of the in-situ synthesized microparticle-enhanced thermal control functional film layer on the surface of 7B04 aluminum alloy prepared in Example 3 of the present invention. Figure 8 Infrared emissivity diagrams of the in-situ synthesized microparticle-enhanced thermal control functional film layer on the surface of 7B04 aluminum alloy prepared in Examples 1-3 of this invention. Detailed Implementation

[0008] The specific implementation of the present invention will be described in detail below with reference to examples and specific circumstances.

[0009] The present invention can be described in the following embodiments. Example

[0010] A method for preparing an in-situ synthesized microparticle-reinforced thermal control functional film on the surface of 7B04 aluminum alloy, comprising the following steps: S1, Material Pretreatment S1.1, 7B04 aluminum alloy surface pretreatment: The 7B04 aluminum alloy sample (size: diameter 25mm, thickness 5mm) was polished and rust removed in sequence with 600#, 800#, 1000#, 1200# and 1500# metallographic sandpaper to remove surface oxides and oil stains. Then, it was ultrasonically treated at 40KHz for 20min in anhydrous ethanol, and then the aluminum alloy surface was rinsed with deionized water and dried for later use. S1.2 Pretreatment of copper oxide and chromium oxide: Copper oxide and chromium oxide were ultrasonically cleaned in anhydrous ethanol for 30 min at 40 kHz, respectively. Then they were centrifuged in a centrifuge at 9600 r / min for 20 min. After discarding the cleaning solution, the obtained copper oxide and chromium oxide were placed in a vacuum drying oven and dried at 95℃ for 3 h for later use. S2. Preparation of micro-arc oxidation electrolyte First, 150g of sodium hexametaphosphate, 50g of sodium tetraborate, 25g of sodium hydroxide, and 25ml of triethanolamine were added sequentially to deionized water to a volume of 5L, and stirred thoroughly until the added substances were completely dissolved. Then, 34.5g of a mixture of copper oxide and chromium oxide was added, and stirred until the solution was evenly dispersed to prepare the micro-arc oxidation electrolyte of the multi-component system. The mass ratio of copper oxide to chromium oxide was 1:2, and the particle size of both copper oxide and chromium oxide was 100nm. S3. Preparation of functional film layers The pretreated 7B04 aluminum alloy was placed in the stainless steel electrolytic cell of the micro-arc oxidation equipment, with the 7B04 aluminum alloy as the anode and the stainless steel electrolytic cell as the cathode. The micro-arc oxidation electrolyte prepared in step S2 was added to the stainless steel electrolytic cell, and the aluminum alloy was subjected to micro-arc oxidation treatment using a micro-arc oxidation power supply. The micro-arc oxidation process parameters were: current: 8A / dm 2 The frequency was 300Hz, the duty cycle was 25%, and the electrolyte temperature was adjusted to 22℃ using a low-temperature constant temperature bath. The micro-arc oxidation treatment time was 32min. During the entire oxidation process, the electrolyte was continuously stirred at a speed of 1450r / min. Finally, an in-situ synthesized microparticle-reinforced thermal control functional film was obtained on the surface of 7B04 aluminum alloy. The film was rinsed with deionized water and air-dried to obtain an in-situ synthesized microparticle-reinforced thermal control functional film with a thickness of 47μm on the surface of 7B04 aluminum alloy. Example

[0011] A method for preparing an in-situ synthesized microparticle-reinforced thermal control functional film on the surface of 7B04 aluminum alloy, comprising the following steps: S1, Material Pretreatment S1.1, 7B04 aluminum alloy surface pretreatment: The 7B04 aluminum alloy sample (size: diameter 25mm, thickness 5mm) was polished and rust removed in sequence with 600#, 800#, 1000#, 1200# and 1500# metallographic sandpaper to remove surface oxides and oil stains. Then, it was ultrasonically treated at 40KHz for 30min in anhydrous ethanol, and then the aluminum alloy surface was rinsed with deionized water and dried for later use. S1.2 Pretreatment of copper oxide and chromium oxide: Copper oxide and chromium oxide were ultrasonically cleaned in anhydrous ethanol for 20 min at 40 kHz, respectively. Then they were centrifuged in a centrifuge at 8500 r / min for 25 min. After discarding the cleaning solution, the obtained copper oxide and chromium oxide were placed in a vacuum drying oven and dried at 120℃ for 2 h for later use. S2. Preparation of micro-arc oxidation electrolyte First, 150g of sodium hexametaphosphate, 50g of sodium tetraborate, 25g of sodium hydroxide, and 25ml of triethanolamine were added sequentially to deionized water to a volume of 5L, and stirred thoroughly until the added substances were completely dissolved. Then, 43.5g of a mixture of copper oxide and chromium oxide was added, and stirred until the solution was evenly dispersed to prepare the micro-arc oxidation electrolyte of the multi-component system. The mass ratio of copper oxide to chromium oxide was 1:2, and the particle size of both copper oxide and chromium oxide was 50nm. S3. Preparation of functional film layers The pretreated 7B04 aluminum alloy was placed in the stainless steel electrolytic cell of the micro-arc oxidation equipment, with the 7B04 aluminum alloy as the anode and the stainless steel electrolytic cell as the cathode. The micro-arc oxidation electrolyte prepared in step S2 was added to the stainless steel electrolytic cell, and the aluminum alloy was subjected to micro-arc oxidation treatment using a micro-arc oxidation power supply. The micro-arc oxidation process parameters were: current: 8A / dm 2 The frequency was 300Hz, the duty cycle was 25%, and the electrolyte temperature was adjusted to 20℃ using a low-temperature constant temperature bath. The micro-arc oxidation treatment time was 45min. During the entire oxidation process, the electrolyte was continuously stirred at a speed of 1500r / min. Finally, an in-situ synthesized microparticle-reinforced thermal control functional film was obtained on the surface of 7B04 aluminum alloy. The film was rinsed with deionized water and air-dried to obtain an in-situ synthesized microparticle-reinforced thermal control functional film with a thickness of 62μm on the surface of 7B04 aluminum alloy. Example

[0012] A method for preparing an in-situ synthesized microparticle-reinforced thermal control functional film on the surface of 7B04 aluminum alloy, comprising the following steps: S1.1, 7B04 aluminum alloy surface pretreatment: The 7B04 aluminum alloy sample (size: diameter 25mm, thickness 5mm) was polished and rust removed in sequence with 600#, 800#, 1000#, 1200# and 1500# metallographic sandpaper to remove surface oxides and oil stains. Then, it was ultrasonically treated at 40KHz for 25min in anhydrous ethanol. The aluminum alloy surface was then rinsed with deionized water and dried for later use. S1.2 Pretreatment of copper oxide and chromium oxide: Copper oxide and chromium oxide were ultrasonically cleaned in anhydrous ethanol for 25 min at 40 kHz, respectively. Then they were centrifuged in a centrifuge at 8000 r / min for 30 min. After discarding the cleaning solution, the obtained copper oxide and chromium oxide were placed in a vacuum drying oven and dried at 110℃ for 2.5 h for later use. S2. Preparation of micro-arc oxidation electrolyte First, 150g of sodium hexametaphosphate, 50g of sodium tetraborate, 25g of sodium hydroxide, and 25ml of triethanolamine were added sequentially to deionized water to a volume of 5L, and stirred thoroughly until the added substances were completely dissolved. Then, 60.0g of a mixture of copper oxide and chromium oxide was added, and stirred until the solution was evenly dispersed to prepare the micro-arc oxidation electrolyte of the multi-component system. The mass ratio of copper oxide to chromium oxide was 1:2, and the particle size of both copper oxide and chromium oxide was 200nm. S3. Preparation of functional film layers The pretreated 7B04 aluminum alloy was placed in the stainless steel electrolytic cell of the micro-arc oxidation equipment, with the 7B04 aluminum alloy as the anode and the stainless steel electrolytic cell as the cathode. The micro-arc oxidation electrolyte prepared in step S2 was added to the stainless steel electrolytic cell, and the aluminum alloy was subjected to micro-arc oxidation treatment using a micro-arc oxidation power supply. The micro-arc oxidation process parameters were: current: 8A / dm 2 The frequency was 300Hz, the duty cycle was 25%, and the electrolyte temperature was adjusted to 25℃ using a low-temperature constant temperature bath. The micro-arc oxidation treatment time was 25min. During the entire oxidation process, the electrolyte was continuously mechanically stirred at a speed of 1750r / min. Finally, an in-situ synthesized microparticle-reinforced thermal control functional film was obtained on the surface of 7B04 aluminum alloy. The film was rinsed with deionized water and air-dried to obtain an in-situ synthesized microparticle-reinforced thermal control functional film with a thickness of 38μm on the surface of 7B04 aluminum alloy.

[0013] It should be noted that the above descriptions are merely illustrative embodiments used to illustrate specific implementations of the present invention, and are not intended to limit the present invention in any form or substance. It should be pointed out that those skilled in the art can make several improvements and additions without departing from the method of the present invention, but these improvements and additions are essentially the same as the technical solution of this application, and should also be considered within the scope of protection of the present invention. Any modifications, alterations, and equivalent changes made by those skilled in the art based on the above-disclosed technical content without departing from the spirit and scope of the present invention are equivalent embodiments of the present invention; at the same time, any modifications, alterations, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical solution of the present invention.

[0014] This invention designs the composition of a micro-arc oxidation electrolyte to synthesize copper chromium black particles in situ via chemical reaction during the growth of the micro-arc oxidation film. The particles exhibit a metallurgical bond with the film, and are uniformly dispersed within the film, effectively improving film density. Simultaneously, the film exhibits high infrared emissivity and good thermal control. Experiments have demonstrated very good and beneficial technical effects, as detailed below: 1. XRD pattern determination XRD pattern of in-situ synthesized microparticle-reinforced thermal control functional film on the surface of 7B04 aluminum alloy, see [link to XRD pattern]. Figure 1 As shown, the phase analysis results show that there is a copper chromium black phase (CuCr2O4) in the film, indicating that the copper chromium black synthesized in situ during the micro-arc oxidation process of copper oxide and chromium oxide exists in the film.

[0015] 2. Hardness Measurement The microhardness of the in-situ synthesized microparticle-reinforced thermal control functional film on the surface of 7B04 aluminum alloy prepared in Examples 1-3 was tested, and the hardness values ​​were 1340HV, 1360HV and 1320HV respectively.

[0016] 3. Macroscopic morphology determination Macroscopic morphology of the in-situ synthesized microparticle-reinforced thermal control functional film on the surface of 7B04 aluminum alloy is shown in the figure. Figure 2-4 As shown, the film layers are all black with uniform color, and no obvious ablation, cracking, or blistering was found on the surface.

[0017] 4. Microscopic morphology determination The SEM microstructure of the in-situ synthesized microparticle-enhanced thermal control functional film on the surface of 7B04 aluminum alloy in Example 1 is shown in Figure 1. Figure 5 As shown, the membrane has a small number of micropores with small pore size and a dense microstructure. The SEM microstructure of the in-situ synthesized microparticle-enhanced thermal control functional film on the surface of 7B04 aluminum alloy in Example 2 is shown in Figure 2. Figure 6 As shown, the film layer has a large number of dense regions, and the micropores in the film layer are small in diameter and few in number, which is beneficial to improving the hardness of the film layer. The SEM microstructure of the in-situ synthesized microparticle-reinforced thermal control functional film on the surface of 7B04 aluminum alloy in Example 3 is shown in Figure 3. Figure 7 As shown, the membrane structure exhibits high density, with few and small micropores, reducing the performance degradation caused by pore defects. 5. Infrared emissivity measurement The infrared emissivity of the in-situ synthesized microparticle-enhanced thermal control functional film layers on the surface of 7B04 aluminum alloy prepared by the methods in Examples 1-3 was measured, and the infrared emissivity was found to be 0.89, 0.93 and 0.90, respectively.

[0018] In summary, this invention can effectively improve the film density, while also exhibiting high infrared emissivity and good thermal control. Compared with existing technologies, its main advantages are: (1) During the micro-arc oxidation process, copper oxide and chromium oxide in the electrolyte are used to synthesize copper chromium black particles (CuCr2O4) through in-situ reaction. This results in an in-situ synthesized microparticle-enhanced thermal control film on the surface of 7B04 aluminum alloy. The film thickness is 32–45 μm when the micro-arc oxidation time is 20–30 min; 45–60 μm when the time is 30–40 min; and 60–65 μm when the time is 40–50 min. The micro-arc oxidation process is short, the film formation rate is fast, the thickness is controllable, and the electrolyte composition is simple and reusable, making it suitable for mass production.

[0019] (2) Under the voltage conditions of 400 to 550V for micro-arc oxidation, by controlling the concentration of copper oxide and chromium oxide, the concentration of in-situ synthesized copper chromium black particles and the thickness of the film layer in the composite micro-arc oxidation film layer are guaranteed, thus avoiding the problem of excessively high micro-arc oxidation voltage caused by excessively thick film layer.

[0020] (3) Compared with conventionally added particles, the in-situ synthesized copper chromium black particles obtained by the method of the present invention are metallurgically bonded to the film layer. The copper chromium black particles are small and uniformly distributed in the film layer, reducing the number of micropores and microcracks in the film layer, increasing the film layer density, and improving the film layer hardness. The in-situ synthesized microparticle-enhanced thermal control film layer prepared by the method of the present invention has a hardness of 1290-1390 HV, which is significantly better than the film layer prepared in an electrolyte without added copper oxide and chromium oxide (with the same other components) (hardness of 820-860 HV).

[0021] (4) The in-situ synthesized microparticle-enhanced thermal control functional film obtained by the method of the present invention has high density and infrared emissivity of up to 0.93. It realizes the unity of film microstructure and thermal control function, which is a major innovation in the field of metal material surface treatment technology and has practical application value.

Claims

1. A method for preparing a micro-particle reinforced thermal control functional film layer on the surface of 7B04 aluminum alloy in situ, characterized in that, It is realized by the following steps: S1, material pretreatment S1.1, 7B04 aluminum alloy surface pretreatment: 600#, 800#, 1000#, 1200#, 1500# metallographic sandpaper is used to polish and rust remove 7B04 aluminum alloy, remove surface oxide and oil stain, then ultrasonic treatment in anhydrous ethanol for 40KHz for 15-30min, then rinse the aluminum alloy surface with deionized water, dry and ready for use; S1.2, copper oxide and chromium oxide pretreatment: copper oxide and chromium oxide are respectively treated by ultrasonic cleaning in anhydrous ethanol for 20-40min, 40KHz, then placed in a centrifuge at a speed of 8000-10000r / min for 15-30min, after discarding the cleaning solution, the obtained copper oxide and chromium oxide are respectively placed in a vacuum drying box and dried at 80-130℃ for 1-3h, ready for use; S2, preparation of micro-arc oxidation electrolyte First, phosphate, borate, sodium hydroxide and organic additive are added to deionized water in sequence, and fully stirred until the added substances are completely dissolved; then copper oxide and chromium oxide are added, and stirred until the solution is uniformly dispersed, to prepare the micro-arc oxidation electrolyte of the used multi-component system; wherein the phosphate is sodium hexametaphosphate, the concentration is 30g / L; the borate is sodium tetraborate, the concentration is 10g / L; the organic additive is triethanolamine, the concentration is 5ml / L; the concentration of sodium hydroxide is 5g / L; the concentration of the mixture of copper oxide and chromium oxide is 5-17g / L, the mass ratio of copper oxide to chromium oxide is 1:2, and the particle size of copper oxide and chromium oxide is 20-500nm; S3, preparation of functional film layer The pretreated 7B04 aluminum alloy is placed in a stainless steel electrolytic cell of a micro-arc oxidation device, the 7B04 aluminum alloy is used as an anode, the stainless steel electrolytic cell is used as a cathode, the micro-arc oxidation electrolyte prepared in step S2 is added into the stainless steel electrolytic cell, and the aluminum alloy is subjected to micro-arc oxidation treatment by using a micro-arc oxidation power supply; the micro-arc oxidation treatment process parameters are as follows: current: 8 A / dm 2 , frequency: 300 Hz, duty cycle: 25%, the temperature of the electrolyte is adjusted by using a low-temperature constant-temperature tank to be 20-25 DEG C, the micro-arc oxidation treatment time is 20-50 min; the electrolyte is subjected to mechanical stirring at a speed of 1000-2000 r / min without interruption during the whole oxidation treatment process, and finally the in-situ synthesized micro-particle reinforced thermal control functional film layer is obtained on the surface of the 7B04 aluminum alloy, the 7B04 aluminum alloy is washed with deionized water, naturally air-dried, and the in-situ synthesized micro-particle reinforced thermal control functional film layer with a thickness of 32-65 mu m is obtained on the surface of the 7B04 aluminum alloy.

2. The method of claim 1, wherein the in-situ synthesis of microparticle reinforced thermal control functional film layer on the surface of 7B04 aluminum alloy is characterized by, It is realized by the following steps: S1, material pretreatment S1.1, 7B04 aluminum alloy surface pretreatment: 600#, 800#, 1000#, 1200#, 1500# metallographic sandpaper is used to polish and rust remove 7B04 aluminum alloy, remove surface oxide and oil stain, then ultrasonic treatment in anhydrous ethanol for 40KHz for 15-30min, then rinse the aluminum alloy surface with deionized water, dry and ready for use; S1.2, copper oxide and chromium oxide pretreatment: copper oxide and chromium oxide are respectively treated by ultrasonic cleaning in anhydrous ethanol for 20-40min, 40KHz, then placed in a centrifuge at a speed of 8000-10000r / min for 15-30min, after discarding the cleaning solution, the obtained copper oxide and chromium oxide are respectively placed in a vacuum drying box and dried at 80-130℃ for 1-3h, ready for use; S2, preparation of micro-arc oxidation electrolyte First, 150g sodium hexametaphosphate, 50g sodium tetraborate, 25g sodium hydroxide and 25ml triethanolamine are added to deionized water to 5L in sequence, and fully stirred until the added substances are completely dissolved; then 34.5g of copper oxide and chromium oxide mixture is added, and stirred until the solution is uniformly dispersed, to prepare the micro-arc oxidation electrolyte of the used multi-component system; the mass ratio of copper oxide to chromium oxide is 1:2, and the particle size of copper oxide and chromium oxide is 100nm; S3, preparation of functional film layer The pretreated 7B04 aluminum alloy is placed in a stainless steel electrolytic cell of a micro-arc oxidation device, the 7B04 aluminum alloy is used as an anode, the stainless steel electrolytic cell is used as a cathode, the micro-arc oxidation electrolyte prepared in step S2 is added into the stainless steel electrolytic cell, and the aluminum alloy is subjected to micro-arc oxidation treatment by using a micro-arc oxidation power supply; the micro-arc oxidation treatment process parameters are as follows: current: 8 A / dm 2 , frequency: 300 Hz, duty cycle: 25%, the temperature of the electrolyte is adjusted by using a low-temperature constant-temperature tank to be 22 DEG C, the micro-arc oxidation treatment time is 32 min; the electrolyte is subjected to mechanical stirring at a speed of 1450 r / min without interruption during the whole oxidation treatment process, and finally the in-situ synthesized micro-particle reinforced thermal control functional film layer is obtained on the surface of the 7B04 aluminum alloy, the 7B04 aluminum alloy is washed with deionized water, naturally air-dried, and the in-situ synthesized micro-particle reinforced thermal control functional film layer with a thickness of 47 mu m is obtained on the surface of the 7B04 aluminum alloy.

3. The method of claim 1, wherein the in-situ synthesis of microparticle reinforced thermal control functional film layer on the surface of 7B04 aluminum alloy is characterized by, It is realized by the following steps: The application relates to a preparation method of a micro-particle reinforced thermal control functional film layer synthesized in situ on a 7B04 aluminum alloy surface. S1, material pretreatment S1.1, 7B04 aluminum alloy surface pretreatment: 7B04 aluminum alloy samples with the size of 25mm in diameter and 5mm in thickness are polished and rusted by using 600#, 800#, 1000#, 1200# and 1500# metallographic sandpaper in sequence, surface oxides and oil stains are removed, then ultrasonic treatment is carried out on the samples in anhydrous ethanol for 25min, the aluminum alloy surface is washed by deionized water, and the samples are dried for standby; S1.2, copper oxide and chromium oxide pretreatment: copper oxide and chromium oxide are respectively subjected to ultrasonic cleaning treatment in anhydrous ethanol for 20min and 40KHz, then are placed in a centrifuge and centrifuged at the speed of 8500r / min for 25min, the cleaning liquid is discarded, and the obtained copper oxide and chromium oxide are respectively placed in a vacuum drying box and dried at 120 DEG C for 2h for standby; S2, preparation of micro-arc oxidation electrolyte Firstly, 150g of sodium hexametaphosphate, 50g of sodium tetraborate, 25g of sodium hydroxide and 25ml of triethanolamine are sequentially added into deionized water to 5L, and are fully stirred until the added substances are completely dissolved; then 43.5g of a copper oxide and chromium oxide mixture is added, and stirring is carried out until the solution is uniformly dispersed, so that the micro-arc oxidation electrolyte of the used multi-component system is prepared; the mass ratio of the copper oxide and the chromium oxide is 1:2, and the particle sizes of the copper oxide and the chromium oxide are both 50nm; S3, preparation of the functional film layer The pretreated 7B04 aluminum alloy is placed in a stainless steel electrolytic cell of a micro-arc oxidation device, the 7B04 aluminum alloy is used as an anode, the stainless steel electrolytic cell is used as a cathode, the micro-arc oxidation electrolyte prepared in step S2 is added into the stainless steel electrolytic cell, and the aluminum alloy is subjected to micro-arc oxidation treatment by using a micro-arc oxidation power supply; the micro-arc oxidation treatment process parameters are as follows: current: 8 A / dm 2 , frequency: 300 Hz, duty cycle: 25%, the temperature of the electrolyte is adjusted to 20 DEG C by using a low-temperature constant-temperature tank, the micro-arc oxidation treatment time is 45 min; the electrolyte is subjected to mechanical stirring at a speed of 1500 r / min without interruption during the whole oxidation treatment process, and finally the in-situ synthesized micro-particle reinforced thermal control functional film layer is obtained on the surface of the 7B04 aluminum alloy, the 7B04 aluminum alloy is washed with deionized water, naturally air-dried, and the in-situ synthesized micro-particle reinforced thermal control functional film layer with a thickness of 62 mu m is obtained on the surface of the 7B04 aluminum alloy.

4. The method of claim 1, wherein the in-situ synthesis of microparticle reinforced thermal control functional film layer on the surface of 7B04 aluminum alloy is characterized by, The application relates to a preparation method of a micro-particle reinforced thermal control functional film layer synthesized in situ on a 7B04 aluminum alloy surface. S1.1, 7B04 aluminum alloy surface pretreatment: 7B04 aluminum alloy samples with the size of 25mm in diameter and 5mm in thickness are polished and rusted by using 600#, 800#, 1000#, 1200# and 1500# metallographic sandpaper in sequence, surface oxides and oil stains are removed, then ultrasonic treatment is carried out on the samples in anhydrous ethanol for 25min, the aluminum alloy surface is washed by deionized water, and the samples are dried for standby; S1.2, copper oxide and chromium oxide pretreatment: copper oxide and chromium oxide are respectively subjected to ultrasonic cleaning treatment in anhydrous ethanol for 20min and 40KHz, then are placed in a centrifuge and centrifuged at the speed of 8500r / min for 25min, the cleaning liquid is discarded, and the obtained copper oxide and chromium oxide are respectively placed in a vacuum drying box and dried at 120 DEG C for 2h for standby; S2, preparation of micro-arc oxidation electrolyte Firstly, 150g of sodium hexametaphosphate, 50g of sodium tetraborate, 25g of sodium hydroxide and 25ml of triethanolamine are sequentially added into deionized water to 5L, and are fully stirred until the added substances are completely dissolved; then 43.5g of a copper oxide and chromium oxide mixture is added, and stirring is carried out until the solution is uniformly dispersed, so that the micro-arc oxidation electrolyte of the used multi-component system is prepared; the mass ratio of the copper oxide and the chromium oxide is 1:2, and the particle sizes of the copper oxide and the chromium oxide are both 50nm; S3, preparation of the functional film layer ​ The pretreated 7B04 aluminum alloy is placed in a stainless steel electrolytic cell of a micro-arc oxidation device, the 7B04 aluminum alloy is used as an anode, the stainless steel electrolytic cell is used as a cathode, the micro-arc oxidation electrolyte prepared in step S2 is added into the stainless steel electrolytic cell, and the aluminum alloy is subjected to micro-arc oxidation treatment by using a micro-arc oxidation power supply; the micro-arc oxidation treatment process parameters are as follows: current: 8 A / dm 2 , frequency: 300 Hz, duty cycle: 25%, the temperature of the electrolyte is adjusted to 25 DEG C by using a low-temperature constant-temperature tank, the micro-arc oxidation treatment time is 25 min; the electrolyte is subjected to mechanical stirring at a speed of 1750 r / min without interruption during the whole oxidation treatment process, and finally the in-situ synthesized micro-particle reinforced thermal control functional film layer is obtained on the surface of the 7B04 aluminum alloy, the 7B04 aluminum alloy is washed with deionized water, naturally air-dried, and the in-situ synthesized micro-particle reinforced thermal control functional film layer with a thickness of 38 mu m is obtained on the surface of the 7B04 aluminum alloy.

Images