A Local Rapid Repair Technology for Rare Earth Magnesium Alloy Phosphate Chemical Conversion Coating

Abstract

The present application discloses a local rapid repair technology for rare earth magnesium alloy phosphate chemical conversion coatings in the technical field of metal material surface chemical treatment. This solution reduces the influence of the external environment on the repair by covering the damaged part of the coating with a rapid repair solution in combination with a repair plate, and improves the success rate of the repair. When the repair solution inside the moisture pad enters the liquid storage cavity under the action of gravity, the liquid-absorbing magnetic ball adsorbs a large amount of the repair solution. The electromagnetic strip generates intermittent magnetic attraction to attract the liquid-absorbing magnetic strip to impact on the ball blocking plate, sputtering the repair solution inside it. The repair solution flows back to the moisture pad from above, keeping the moisture pad moist and improving the repair efficiency. A protective layer with a protective effect can be rapidly obtained at room temperature. The present invention solves the problem of the decline in corrosion resistance caused by the damage of the surface protective layer of rare earth magnesium alloys in the aerospace field, and can ensure the reliability and stability of the service of products such as aircraft, satellites, and model weapons.

Description

Technical Field

[0001] This application relates to the technical field of surface chemical treatment of metal materials, and particularly to a technology for rapid local repair of phosphate chemical conversion films on rare earth magnesium alloys. Background Art

[0002] With the development of China's aerospace technology, there is an urgent need for lightweight in the fields of aircraft, satellites, and model weapons. Against the background of limited weight reduction through structural optimization, high-strength and heat-resistant rare earth magnesium alloys in aerospace materials have been gradually applied in the fields of aircraft, satellites, and model weapons. However, the corrosion resistance of magnesium alloys themselves is poor, and corrosion problems will occur after long-term exposure to the external environment, affecting the reliability and stability of the service of national weaponry, posing a challenge to the surface protection technology of rare earth magnesium alloys.

[0003] Phosphate chemical conversion technology, as an environmentally friendly surface treatment method, has been applied in the aerospace field. However, the phosphate chemical conversion film layer on the surface of aerospace equipment will experience wear during subsequent assembly and service, and the corrosion resistance of the damaged part of the film layer will be significantly reduced, affecting the normal service life of aerospace equipment. Therefore, it is necessary to develop a local rapid repair technology to solve the problem of the decline in the corrosion resistance of aerospace equipment caused by local damage to the film layer.

[0004] The local rapid repair technology is reflected in rapidly obtaining a protective film with a protective effect at room temperature. This technology has not formed a mature technical system in the aerospace field, resulting in the local repair of equipment in the aerospace field becoming a bottleneck problem. To solve the above problems, the present invention provides a technology for rapid local repair of phosphate chemical conversion films on rare earth magnesium alloys, which can achieve rapid repair of locally damaged film layers during the process of engineering application. Summary of the Invention

[0005] The purpose of this application is to improve the corrosion resistance of damaged parts through treatment with a room temperature phosphating solution, which can solve the problem of the decline in corrosion resistance caused by local damage to the phosphate chemical conversion film layer of rare earth magnesium alloys at present, and provide a technology for rapid local repair of phosphate chemical conversion films on rare earth magnesium alloys, including the following steps:

[0006] Step 1, preparation of phosphate chemical conversion solution: Dissolve 15 - 80 g / L of dihydrogen phosphate, 5 - 50 g / L of manganese nitrate, 1 - 30 g / L of sulfuric acid, and 1 - 30 g / L of surfactant in deionized water respectively, and then mix them fully and stir evenly;

[0007] Step 2, perform pretreatment on the phosphate chemical conversion film layer of rare earth magnesium alloy, then polish it flat with sandpaper, wipe it with acetone, and then wash it with pure water;

[0008] Step 3: Inject the quick repair solution prepared in Step 1 into the moisture pad embedded at the front end of the repair plate, and then attach the repair plate to the metal surface to be repaired, and let it stand at room temperature for 30 - 60 s;

[0009] Step: After removing the repair plate, wipe the remaining quick repair solution with absorbent cotton and clean it with deionized water, and dry it at room temperature.

[0010] The moisture pad adsorbs a large amount of quick repair solution and adheres to the metal surface to be repaired, enabling it to quickly obtain a protective layer with a protective effect at room temperature, effectively repairing the damaged area of the surface protective layer of the rare earth magnesium alloy, and improving the corrosion resistance of the rare earth magnesium alloy.

[0011] Further, the dihydrogen phosphate is sodium dihydrogen phosphate, and the surfactant is sodium dodecyl sulfate.

[0012] Further, the mass ratio of sodium dihydrogen phosphate, manganese nitrate, sulfuric acid, sodium dodecyl sulfate and deionized water is 30 - 50:5 - 20:1 - 4:1 - 5:1000.

[0013] Further, 800# and 1200# sandpapers are used, and the fineness of the sandpaper is gradually increased to polish the metal surface to be repaired, so that the surface to be repaired remains flat, improving the integrity and wholeness of the repair.

[0014] Further, the standing temperature is 10 - 40 °C, and the drying temperature is 10 - 40 °C.

[0015] Further, a reserved groove is provided at the front end of the repair plate, the moisture pad is arranged inside the reserved groove, a liquid storage cavity corresponding to the position of the reserved groove is provided inside the repair plate, a plurality of liquid-absorbing magnetic balls are filled inside the liquid storage cavity, a plurality of pores communicating with each other are provided on the outer wall of the liquid-absorbing magnetic ball, an electromagnetic strip corresponding to the position of the liquid-absorbing magnetic ball is provided inside the repair plate, the electromagnetic strip is connected to an external controller through a wire, a ball-blocking plate is provided at the upper end of the liquid storage cavity, a plurality of grooves are provided on the ball-blocking plate, a plurality of liquid guiding holes are provided on the ball-blocking plate, and a plurality of communication holes communicating with the inside of the liquid storage cavity are provided on the bottom wall of the reserved groove. The moisture pad is used to absorb a large amount of repair solution and fit on the surface to be repaired, reducing the influence of the external environment on the repair and improving the success rate of the repair. When the repair solution inside the moisture pad enters the liquid storage cavity under the action of gravity, the liquid-absorbing magnetic balls adsorb a large amount of repair solution, and the electromagnetic strip is used to generate intermittent magnetism to attract the liquid-absorbing magnetic balls to impact on the ball-blocking plate to sputter the repair solution inside it, and the repair solution flows back to the moisture pad from above, keeping the moisture pad moist and improving the repair efficiency.

[0016] Further, a filter cavity is provided between the ball baffle and the upper end of the liquid storage cavity. The filter cavity is filled with a filter element made of natural fiber material. The filter element can quickly absorb the sputtered repair solution and adsorb the impurities in the repair solution at the same time, reducing the pollution to the repair surface and improving the repair quality.

[0017] Further, the ball baffle is provided with a plurality of grooves adapted to the liquid-absorbing magnetic balls. The ball baffle is arranged obliquely upward from left to right. The inclined ball baffle enables the repair solution to quickly flow back to the moisture pad, and the grooves can absorb the repair solution inside the liquid-absorbing magnetic balls in all directions.

[0018] Further, the moisture pad includes an expansion layer in the middle, and water-permeable films are provided on both sides of the expansion layer. The expansion layer is woven from natural fiber material. The expansion layer absorbs the repair solution and expands in volume, making the water-permeable film more closely attached to the surface to be repaired, improving the repair efficiency.

[0019] Further, a plurality of chutes are provided on the upper walls at both ends of the repair plate. Suction cups are slidably arranged inside the chutes. The bottom of the suction cup is connected to the bottom wall of the chute through a spring. The suction cup enables the repair plate to be closely attached to the outer wall of the repair surface, effectively improving the repair quality and efficiency.

[0020] Compared with the prior art, the advantages of the present application are as follows:

[0021] (1) By adsorbing a large amount of quick repair solution through the moisture pad and attaching it to the metal surface to be repaired, a protective layer with a protective effect can be quickly obtained at normal temperature, effectively repairing the damaged area of the surface protective layer of the rare earth magnesium alloy and improving the corrosion resistance of the rare earth magnesium alloy.

[0022] (2) The repair solution of the present invention is simple to prepare and has a long shelf life;

[0023] (3) After quick repair, the color difference of the film layer is small and the surface consistency is good;

[0024] (4) The film layer has a double-layer structure, is thick and dense, and can maintain a good surface protection effect for a long time.

[0025] (5) By using the moisture pad to absorb a large amount of repair solution and attach it to the surface to be repaired, the influence of the external environment on the repair is reduced, and the repair success rate is improved. When the repair solution inside the moisture pad enters the liquid storage cavity under the action of gravity, the liquid-absorbing magnetic balls adsorb a large amount of repair solution. The electromagnetic strip generates intermittent magnetism to attract the liquid-absorbing magnetic balls to impact on the ball baffle and sputter the repair solution inside it. The repair solution flows back to the moisture pad from above, keeping the moisture pad moist and improving the repair efficiency. Description of the Drawings

[0026] Figure 1Microscopic surface topography photo of the surface after rapid repair;

[0027] Figure 2 Microscopic cross-sectional topography photo of the surface after rapid repair;

[0028] Figure 3 Schematic structural diagram of the repair plate of the present application;

[0029] Figure 4 Exploded view of the repair plate of the present application;

[0030] Figure 5 Cross-sectional view of the repair plate of the present application attached to the surface of a metal part;

[0031] Figure 6 Is Figure 5 Enlarged view of area A in

[0032] Figure 7 Schematic structural diagram of the liquid-absorbing magnetic ball of the present application;

[0033] Figure 8 Schematic structural diagram of the moisture retention pad of the present application;

[0034] Figure 9 Cross-sectional view of the repair plate of the present application attached to the surface of a metal part in the working state;

[0035] Figure 10 Is Figure 9 Enlarged view of area B in

[0036] Explanation of the reference numerals in the figure:

[0037] 1. Repair plate; 11. Reserved groove; 12. Slide groove; 13. Electromagnetic strip; 14. Liquid storage cavity; 15. Ball blocking plate; 16. Filter element; 2. Moisture retention pad; 21. Permeable thin film; 22. Expansion layer; 3. Suction cup; 4. Liquid-absorbing magnetic ball. Specific implementation mode

[0038] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0039] Embodiment 1:

[0040] Please refer to Figure 1-2 , in this embodiment, a surface protection film layer is sprayed on the surface of VW63Z magnesium alloy at room temperature using a rapid repair solution, and the implementation is carried out according to the following steps:

[0041] Step 1, prepare the components of the rapid repair solution: sodium dihydrogen phosphate 50 g / L, manganese nitrate 15 g / L, sulfuric acid 1 g / L, sodium dodecyl sulfate 2 g / L. Dissolve them separately with deionized water and then mix well.

[0042] Step 2, polish the damaged part of the film layer smoothly with 800# and 1000# sandpapers in sequence to remove the excess, then wipe the surface oil stain with acetone, and then wash it clean with deionized water.

[0043] Step 3, spray the rapid repair solution on the damaged part of the film layer with a spray gun and let it stand for 30 s.

[0044] Step 4, wipe the remaining rapid repair solution with absorbent cotton, wash it clean with deionized water, and dry it at room temperature.

[0045] Example 2:

[0046] Please refer to Figure 1-2 , in this example, a surface protective film layer is formed by spraying the rapid repair solution on the surface of VK100Z magnesium alloy at room temperature, and the implementation steps are as follows:

[0047] Step 1, prepare the components of the rapid repair solution: sodium dihydrogen phosphate 50 g / L, manganese nitrate 15 g / L, sulfuric acid 1 g / L, sodium dodecyl sulfate 2 g / L. Dissolve them separately with deionized water and then mix well.

[0048] Step 2, polish the damaged part of the film layer smoothly with 800# and 1000# sandpapers in sequence to remove the excess, then wipe the surface oil stain with acetone, and then wash it clean with deionized water.

[0049] Step 3, spray the rapid repair solution on the damaged part of the film layer with a spray gun and let it stand for 30 s.

[0050] Step 4, wipe the remaining rapid repair solution with absorbent cotton, wash it clean with deionized water, and dry it at room temperature.

[0051] Example 3:

[0052] Please refer to Figure 1-2 , in this example, a surface protective film layer is formed by brushing the rapid repair solution on the surface of ZK80 magnesium alloy at room temperature, and the implementation steps are as follows:

[0053] Step 1, prepare the components of the rapid repair solution: sodium dihydrogen phosphate 30 g / L, manganese nitrate 10 g / L, sulfuric acid 1 g / L, sodium dodecyl sulfate 2 g / L. Dissolve them separately with deionized water and then mix well.

[0054] Step 2: Use 800# and 1000# sandpaper to smooth the damaged part of the membrane layer, remove the excess, wipe it with acetone to remove the surface oil, and then clean it with deionized water;

[0055] Step 3, spray the quick repair solution on the damaged part of the film layer with a spray gun and let it stand for 60 seconds;

[0056] Step 4: Wipe the remaining quick repair solution with absorbent cotton, rinse with deionized water, and dry at room temperature.

[0057] Embodiment 4:

[0058] See also Figure 1-2 In this embodiment, a quick repair solution is applied to the surface of the ZK90 magnesium alloy at room temperature to form a surface protective film layer, and the following steps are performed:

[0059] Step 1, prepare the quick repair solution ingredients: 30g / L diammonium phosphate, 10g / L manganese nitrate, 2g / L sulfuric acid, 1g / L sodium dodecyl sulfate, dissolve them in deionized water and mix them thoroughly;

[0060] Step 2: Use 800# and 1000# sandpaper to smooth the damaged part of the membrane layer, remove the excess, wipe it with acetone to remove the surface oil, and then clean it with deionized water;

[0061] Step 3: Use a soft brush to apply the quick repair solution to the damaged part of the film layer and let it stand for 60 seconds;

[0062] Step 4: Wipe the remaining quick repair solution with absorbent cotton, rinse with deionized water, and dry at room temperature.

[0063] Embodiment 5:

[0064] See also Figure 1-2 In this embodiment, a quick repair solution is applied to the surface of the ZK90 magnesium alloy at room temperature to form a surface protective film layer, and the following steps are performed:

[0065] Step 1, prepare the quick repair solution ingredients: 30g / L diammonium phosphate, 10g / L manganese nitrate, 2g / L sulfuric acid, 1g / L sodium dodecyl sulfate, dissolve them in deionized water and mix them thoroughly;

[0066] Step 2: Use 800# and 1000# sandpaper to smooth the damaged part of the membrane layer, remove the excess, wipe it with acetone to remove the surface oil, and then clean it with deionized water;

[0067] Step 3: Inject the quick repair solution prepared in Step 1 into the moisture pad 2 embedded at the front end of the repair plate 1, then attach the repair plate 1 to the metal surface to be repaired, and let it stand at room temperature for 30 - 60 s.

[0068] Step 4: After removing the repair plate 1, wipe the remaining quick repair solution with absorbent cotton, and clean it with deionized water, then dry it at room temperature.

[0069] Please refer to Figure 3-7 , a reserved groove 11 is provided at the front end of the repair plate 1, the moisture pad 2 is arranged inside the reserved groove 11, a liquid storage cavity 14 corresponding to the position of the reserved groove 11 is provided inside the repair plate 1, a plurality of liquid-absorbing magnetic balls 4 are filled inside the liquid storage cavity 14, a plurality of interconnected pores are provided on the outer wall of the liquid-absorbing magnetic ball 4, an electromagnetic strip 13 corresponding to the position of the liquid-absorbing magnetic ball 4 is provided inside the repair plate 1, the electromagnetic strip 13 is connected to an external controller through a wire, a ball blocking plate 15 is provided at the upper end of the liquid storage cavity 14, a plurality of grooves are provided on the ball blocking plate 15, a plurality of liquid guiding holes are provided on the ball blocking plate 15, and a plurality of communication holes communicating with the inside of the liquid storage cavity 14 are provided on the bottom wall of the reserved groove 11.

[0070] Please refer to Figure 4-6 , a plurality of sliding grooves 12 are provided on the upper walls at both ends of the repair plate 1, a suction cup 3 is slidably arranged inside the sliding grooves 12, the bottom of the suction cup 3 is connected to the bottom wall of the sliding grooves 12 through a spring, and the repair plate 1 can be tightly attached to the outer wall of the repair surface by using the suction cup 3, effectively improving the repair quality and efficiency.

[0071] Please refer to Figure 6 , a filtering cavity is left between the ball blocking plate 15 and the upper end of the liquid storage cavity 14, a filter element 16 is filled inside the filtering cavity, the filter element 16 is made of natural fiber material, the filter element 16 can quickly absorb the sputtered repair solution, and at the same time adsorb the impurities inside the repair solution, reducing the pollution to the repair surface and improving the repair quality.

[0072] The ball blocking plate 15 is provided with a plurality of grooves adapted to the liquid-absorbing magnetic balls 4, and the ball blocking plate 15 is arranged obliquely upward from left to right. The inclined ball blocking plate 15 enables the repair solution to quickly flow back to the moisture pad 2, and the grooves can absorb the repair solution inside the liquid-absorbing magnetic balls 4 in all directions.

[0073] Please refer to Figure 8 , the moisture pad 2 includes an expansion layer 22 in the middle, water-permeable films 21 are arranged on both sides of the expansion layer 22, the expansion layer 22 is woven from natural fiber material, the expansion layer 22 absorbs the repair solution and expands in volume, making the water-permeable film 21 more tightly attached to the surface to be repaired, improving the repair efficiency.

[0074] Please refer to Figure 9-10, the moisture pad 2 is used to absorb a large amount of repair solution and fit it on the surface to be repaired, reducing the influence of the external environment on the repair and improving the success rate of the repair. When the repair solution inside the moisture pad 2 enters the liquid storage cavity under the action of gravity, the liquid-absorbing magnetic ball 4 adsorbs a large amount of repair solution. The electromagnetic strip 13 is used to generate intermittent magnetism to attract the liquid-absorbing magnetic ball 4 to impact on the ball blocking plate 15, sputtering the repair solution inside it. The repair solution flows back to the moisture pad 2 from above, keeping the moisture pad 2 moist and improving the repair efficiency.

[0075] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application, according to the technical solution and its improvement concept of the present application, makes equivalent substitutions or changes, and should be covered by the protection scope of the present application.

Claims

1. A method for locally and rapidly repairing a rare earth magnesium alloy phosphate chemical conversion film, characterized in that It includes the following steps: Step 1, preparation of phosphate chemical conversion solution: 15 - 80 g / L of dihydrogen phosphate, 5 - 50 g / L of manganese nitrate, 1 - 30 g / L of sulfuric acid, and 1 - 30 g / L of surfactant. The above four reagents are separately dissolved in deionized water, fully mixed together, and stirred evenly; Step 2, pretreat the rare earth magnesium alloy phosphate coating, then polish it flat with sandpaper, wipe it with acetone, and wash it with pure water; Step 3, inject the rapid repair solution prepared in Step 1 into the moisture pad (2) embedded at the front end of the repair plate (1), then attach the repair plate (1) to the metal surface to be repaired, and let it stand at room temperature for 30 - 60 s; Step 4, after removing the repair plate (1), wipe the remaining rapid repair solution with absorbent cotton, wash it clean with deionized water, and dry it at room temperature; A reserved groove (11) is provided at the front end of the repair plate (1), the moisture pad (2) is arranged inside the reserved groove (11), a liquid storage cavity (14) corresponding to the position of the reserved groove (11) is provided inside the repair plate (1), a plurality of liquid-absorbing magnetic balls (4) are filled inside the liquid storage cavity (14), a plurality of interconnected pores are provided on the outer wall of the liquid-absorbing magnetic balls (4), an electromagnetic strip (13) corresponding to the position of the liquid-absorbing magnetic balls (4) is provided inside the repair plate (1), the electromagnetic strip (13) is connected to an external controller through a wire, a ball blocking plate (15) is provided at the upper end of the liquid storage cavity (14), a plurality of grooves are provided on the ball blocking plate (15), a plurality of liquid guiding holes are provided on the ball blocking plate (15), a plurality of communication holes communicating to the inside of the liquid storage cavity (14) are provided on the bottom wall of the reserved groove (11), the moisture pad (2) includes an intermediate expansion layer (22), and water-permeable films (21) are provided on both sides of the expansion layer (22). The expansion layer (22) is woven from natural fiber materials.

2. A method for locally and rapidly repairing a rare earth magnesium alloy phosphate chemical conversion film according to claim 1, characterized in that, The dihydrogen phosphate is sodium dihydrogen phosphate, and the surfactant is sodium dodecyl sulfate.

3. A method for locally and rapidly repairing a rare earth magnesium alloy phosphate chemical conversion film according to claim 2, characterized in that, The mass ratio of sodium dihydrogen phosphate, manganese nitrate, sulfuric acid, sodium dodecyl sulfate, and deionized water is 30 - 50:5 - 20:1 - 4:1 - 5:1000.

4. A method for locally and rapidly repairing a rare earth magnesium alloy phosphate chemical conversion film according to claim 1, characterized in that, The sandpaper used is 800# and 1200#.

5. A method for locally and rapidly repairing a rare earth magnesium alloy phosphate chemical conversion film according to claim 1, characterized in that, The standing temperature in Step 3 is 10 - 40 °C, and the drying temperature in Step 4 is 10 - 40 °C.

6. A method for locally and rapidly repairing a rare earth magnesium alloy phosphate chemical conversion film according to claim 1, characterized in that, A filtering cavity is provided between the ball blocking plate (15) and the upper end of the liquid storage cavity (14), and a filter core (16) is filled inside the filtering cavity. The filter core (16) is made of natural fiber materials.

7. A method for local rapid repair of a rare earth magnesium alloy phosphate chemical conversion film according to claim 1, characterized in that, The ball blocking plate (15) is provided with a plurality of grooves adapted to the liquid-absorbing magnetic balls (4), and the ball blocking plate (15) is arranged obliquely upward from left to right.

8. A method for local rapid repair of a rare earth magnesium alloy phosphate chemical conversion film according to claim 1, characterized in that, A plurality of chutes (12) are provided on the upper walls at both ends of the repair plate (1), suction cups (3) are slidably arranged inside the chutes (12), and the bottom of the suction cups (3) is connected to the bottom wall of the chutes (12) through springs.

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