A method for sealing holes of nickel-free zirconium salt oxide films on aluminum alloy profiles

Abstract

The invention relates to a method for sealing a nickel-free zirconium salt oxide film on an aluminum alloy profile, which mainly solves the problem of poor sealing effect in the prior art. The method comprises the following steps: 1) suspending the aluminum profile in sequence through a suspension assembly and subjecting it to surface pretreatments of sandblasting, oil removal, water washing, alkali washing, water washing, pickling, and water washing; 2) suspending the aluminum profile in an electrolytic tank through the suspension assembly and performing anodizing; 3) air-drying the aluminum profile treated in step 2; 4) suspending the aluminum profile in a sealing tank through the suspension assembly, using an aluminum electrode as an anode and the aluminum profile to be sealed as a cathode and performing pulse power treatment for 25 minutes, while the aluminum profile vibrates and a sealing liquid is circulated and sprayed through a jet steam engine, so that the sealing tank is in an aerated state and the electrolyte temperature is maintained at 70 to 110 degrees Celsius; and 5) cleaning and drying the aluminum profile treated in step 4.

Description

Technical Field

[0001] The invention relates to a method for sealing a nickel-free zirconium salt oxide film on an aluminum alloy profile. Background Art

[0002] Anodizing is one of the most commonly used surface treatments for aluminum alloys. However, the anodic oxide film on aluminum alloys is a honeycomb-like, porous structure with high porosity and strong adsorption properties, making it susceptible to external contamination and corrosion by corrosive media. Therefore, the anodic oxide film must be properly sealed before use. The quality of the sealing is an important indicator of the corrosion resistance of the anodic oxide film, and its quality directly affects the product's service life.

[0003] Micro-arc oxidation films have a porous structure, which, while providing an excellent base for further application of organic coatings, also poses a potential risk of corrosion to the substrate beneath the film. In a corrosive environment, corrosive fluids can penetrate through the micropores and penetrate into the substrate, causing corrosion, significantly reducing the coating's service life. Therefore, to improve the corrosion resistance, anti-pollution, and electrical insulation properties of the oxidized sample while maintaining a durable appearance, appropriate sealing techniques must be employed to close the micropores. Chinese Patent Application No. 201210357957.2 discloses a room-temperature micro-arc oxidation film sealing method. The method employs a solution of sodium silicate, nickel salt, solvent, and accelerator as a sealing agent. After the sealing agent is allowed to stand for at least two hours, the micro-arc oxidation film is immersed in the film at room temperature for pore sealing. After sealing, the sealing agent forms adsorbed crystalline fillers in the micropores on the surface of the micro-arc oxidation film, achieving the purpose of sealing the pores.

[0004] During the sealing process, nickel ions are deposited in the form of nickel hydroxide in the membrane pores, sealing the microporous layer on the surface of the profile. However, there are problems such as dusting, color difference, microcracks in high-temperature environments, aging after sealing, and slow sealing speed. Summary of the Invention

[0005] Therefore, in order to solve the above problems, the present invention provides a method for sealing the holes of aluminum alloy profiles with nickel-free zirconium salt oxide film, which mainly solves the problem of poor sealing effect in the prior art.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for sealing a nickel-free zirconium salt oxide film on an aluminum alloy profile comprises the following steps:

[0008] 1) The aluminum profile is suspended through the suspension assembly and subjected to surface pretreatment in sequence, including sandblasting, degreasing, water washing, alkali washing, water washing, pickling, and water washing;

[0009] 2) The aluminum profile is suspended in an electrolytic cell by a suspension assembly for anodizing. The electrolyte in the electrolytic cell includes sodium hydroxide, sodium silicate, glycerol, disodium EDTA and deionized water;

[0010] 3) After the aluminum profile treated in step 2 is rinsed in deionized water for 2 minutes, it is then ultrasonically shaken in anhydrous ethanol for 3 minutes to remove the residual electrolyte on the surface of the aluminum profile, and then air-dried;

[0011] 4) The aluminum profile is suspended in the sealing tank using a suspension assembly. The aluminum electrode is used as the anode and the aluminum profile to be sealed is used as the cathode. A pulse current treatment is applied for 25 minutes. At the same time, the aluminum profile vibrates and the sealing liquid is circulated through a jet steam engine to aerate the sealing tank. The electrolyte temperature is maintained at 70°C to 110°C. The sealing liquid includes silicate, sodium hydroxide, silane, sodium fluorozirconate, potassium fluorozirconate, glacial acetic acid, and anionic surfactant.

[0012] 5) The aluminum profile treated in step 4 is washed in deionized water, then ultrasonically cleaned in anhydrous ethanol, and dried.

[0013] Furthermore, the pulse power supply constant voltage mode is adopted during the pulse power-on, and the voltage is 80V to 120V, the frequency is 130Hz to 180Hz, and the positive and negative pulse working ratio is 40% to 60%.

[0014] Furthermore, the anionic surfactant is lignin sulfonate.

[0015] Furthermore, the suspension assembly includes a guide device distributed along the direction of the assembly line, a truss mounted on the guide device, a first drive device for driving the truss to move, a longitudinal guide device arranged on the truss, a hanger arranged on the longitudinal guide device, and a second drive device arranged on the truss for driving the hanger. Hook assemblies are provided at both lateral ends of the hanger, and the hook assembly is detachably provided with a connecting piece. Each of the aluminum profiles is hung on the connecting piece, and the connecting piece and the hanger are separated by relative movement along the longitudinal direction.

[0016] Furthermore, the first driving device includes a rack distributed along the direction of the guide device, a first driving motor provided on the truss, and a driving gear provided on the first driving motor and meshing with the rack.

[0017] Furthermore, the second driving device includes a driving shaft and a driven shaft respectively arranged at the upper and lower ends of the truss, a second driving motor connected to the driving shaft, a driving sprocket arranged at both axial ends of the driving shaft, a driven sprocket arranged at both axial ends of the driven shaft, and a chain wound around the driving sprocket and the driven sprocket, and the hanger is fixedly connected to the chain.

[0018] Furthermore, the hook assembly includes a support plate fixed on the hanger, a connecting plate hinged to the hanger and located on the inner side of the support plate, an inclined plate fixedly connected to the connecting plate, and a hook portion provided at the free end of the inclined plate, and a spring is provided between the support plate and the connecting plate.

[0019] Furthermore, the angle between the inclined plate and the connecting plate is 45° to 60°.

[0020] Furthermore, a liquid inlet and a first liquid outlet are provided on the bottom surface of the sealing tank, and a second liquid outlet and an air outlet are provided on the upper part of the sealing tank. The air outlet is distributed on the upper side of the second liquid inlet and is located above the liquid level of the sealing liquid. The second liquid outlet is connected to the liquid inlet through a connecting pipe and a jet steam engine. The air outlet is provided with an air pump. The output end of the air pump is connected to the connecting pipe through an aerator and an air pipe. Metal supports are provided at the upper end of the sealing tank and on both sides. The metal supports are electrically connected to a current controller. A vibration assembly is provided between the metal support and the sealing tank.

[0021] By adopting the above-mentioned technical scheme, the beneficial effects of the present invention are: the nickel-zirconium salt-free oxide film sealing method for aluminum alloy profiles improves the adhesion of the generated oxide film layer, thereby improving the surface density of the aluminum profile, and the sealing effect is obvious, which can better protect the aluminum profile, and the oxide film layer after sealing is flat, uniform, hard and corrosion-resistant. This sealing method reduces energy consumption, causes little damage to the environment, and has energy-saving and environmental protection effects; and, a part of the sealing liquid is converted into water vapor through the steam generator to maintain the temperature of the sealing liquid. At the same time, the water vapor makes it easier for water molecules to enter the anodized film for sealing, and through the vibration of the aluminum profile and the aeration phenomenon of the sealing liquid, the air and dust in the gaps of the oxide film can be better removed, thereby improving the surface cleanliness and thereby improving the uniformity and flatness of the sealing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the structure of the suspension assembly, hook assembly, vibration assembly and sealing groove in an embodiment of the present invention;

[0023] Figure 2 2. It is a structural diagram of a hook assembly, a vibration assembly and a connecting member in an embodiment of the present invention;

[0024] Figure 3 It is another structural schematic diagram of the hook assembly, vibration assembly and connecting member in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0026] The embodiments of the present invention are:

[0027] A method for sealing a nickel-free zirconium salt oxide film on an aluminum alloy profile comprises the following steps:

[0028] 1) The aluminum profile is suspended through the suspension assembly and subjected to surface pretreatment in sequence, including sandblasting, degreasing, water washing, alkali washing, water washing, pickling, and water washing;

[0029] 2) Suspending the aluminum profile into an electrolytic tank for anodizing via a suspension assembly. The electrolyte comprises sodium hydroxide, sodium silicate, glycerol, disodium EDTA, and deionized water.

[0030] 3) After the aluminum profile treated in step 2 is rinsed in deionized water for 2 minutes, it is then ultrasonically shaken in anhydrous ethanol for 3 minutes to remove the residual electrolyte on the surface of the aluminum profile, and then air-dried;

[0031] 4) The aluminum profile is suspended in the sealing tank via a suspension assembly. The aluminum electrode is used as the anode and the aluminum profile to be sealed is used as the cathode. A pulse power supply is applied for 25 minutes. The aluminum profile vibrates and the sealing liquid is circulated and sprayed through a jet steam engine to aerate the sealing tank. The electrolyte temperature is maintained at 95 degrees Celsius. The sealing liquid includes silicate, sodium hydroxide, silane, sodium fluorozirconate, potassium fluorozirconate, glacial acetic acid, and an anionic surfactant. The anionic surfactant is lignin sulfonate. The pulse power supply adopts a constant voltage mode, with a voltage of 110V, a frequency of 160Hz, and a positive and negative pulse duty ratio of 55%.

[0032] 5) The aluminum profile treated in step 4 is washed in deionized water, then ultrasonically cleaned in anhydrous ethanol, and dried.

[0033] The present invention improves the adhesion of the generated oxide film layer through the above-mentioned nickel-free zirconium salt oxide film sealing method for aluminum alloy profiles, thereby improving the surface density of the aluminum profile. The sealing effect is obvious, and can better protect the aluminum profile. Moreover, after sealing, the oxide film layer is flat, uniform, has good hardness and strong corrosion resistance. This sealing method reduces energy consumption, causes little damage to the environment, and achieves energy-saving and environmental protection effects. Moreover, a part of the sealing liquid is converted into water vapor through a steam generator to maintain the temperature of the sealing liquid. At the same time, the water vapor makes it easier for water molecules to enter the anodized film for sealing. Moreover, through the vibration of the aluminum profile and the aeration phenomenon of the sealing liquid, the air and dust in the gaps of the oxide film can be better removed, thereby improving the surface cleanliness and thus improving the uniformity and flatness of the sealing.

[0034] In this embodiment, reference Figure 1 、 Figure 2 and Figure 3As shown, the suspension assembly includes a guide device 1 distributed along the direction of the assembly line, a truss 2 mounted on the guide device 1, a first drive device for driving the truss 2 to move, a longitudinal guide device 3 provided on the truss 2, a hanger 4 provided on the longitudinal guide device 3, and a second drive device provided on the truss 2 for driving the hanger 4. The first drive device includes a rack 5 distributed along the direction of the guide device 1, a first drive motor 6 provided on the truss 2, and a drive gear 7 provided on the first drive motor 6 and engaged with the rack 5. The second drive device includes a driving shaft 8 and a driven shaft respectively provided at the upper and lower ends of the truss 2. 9. A second drive motor (not shown in the figure) connected to the driving shaft 8, a driving sprocket 10 provided at both axial ends of the driving shaft 8, a driven sprocket 11 provided at both axial ends of the driven shaft 9, and a chain 12 wound around the driving sprocket 10 and the driven sprocket 11, the hanger 4 is fixedly connected to the chain 12, and both lateral ends of the hanger 4 are provided with a hook assembly 100, and the hook assembly 100 is detachably provided with a connecting piece 13, each of the aluminum profiles is hung on the connecting piece 13, and the connecting piece 13 is detached from the hook assembly 100 through the relative movement of the connecting piece 13 and the hanger 4 in the longitudinal direction.

[0035] The truss 2 is driven by the first driving device to move along the guide device 1, thereby entering each functional groove respectively, and the hanger 4 is driven by the second driving motor to move up and down, so that the hook assembly 100 on the hanger 4 and the connecting member 13 form relative movement or synchronous movement in the longitudinal direction, thereby realizing the detachment or lifting of the connecting member 13, which can greatly improve the sealing efficiency and safety.

[0036] Specifically, the hook assembly 100 includes a support plate 101 fixed to the hanger 4, a connecting plate 102 hinged to the hanger 4 and located on the inner side of the support plate 101, an inclined plate 103 fixedly connected to the connecting plate 102, and a hook portion 104 provided at the free end of the inclined plate 103. A spring 105 is provided between the support plate 101 and the connecting plate 102. The angle between the inclined plate 103 and the connecting plate 102 is 45°. A protrusion 106 is provided in the middle of the inclined plate 103. By driving the hanger 4 to move downward, the lateral ends of the connecting member 13 are respectively against the inclined plate 103 and move along the inclined plate 103. At the same time, the inclined plate 103 squeezes the spring 105 to move, so that the hook portion 104 hooks the connecting member 13 is lifted and hoisted. When the hanger 4 continues to move downward, the hook 104 disengages from the connector 13. This simple structure is convenient to use and can greatly improve production efficiency. Furthermore, the inclined plate 103 and raised portion 106 are provided. When the connector 13 drives the aluminum profile to vibrate, both ends of the connector 13 abut against the raised portions 106 of the inclined plate 103. This vibration is buffered by the spring 105, preventing it from being transmitted to the hanger 4. The spring 105 also maintains a consistent vibration frequency of the connector 13, and the vibration amplitude and frequency can be guaranteed by squeezing the spring 105. This arrangement, combined with aeration within the sealing slot 14, effectively expels air and fallen dust from the gaps in the oxide film, promoting crystallization and improving the sealing effect.

[0037] Furthermore, a liquid inlet 21 and a first liquid outlet 22 are provided on the bottom surface of the sealing tank 14, and a second liquid outlet 23 and an air outlet 24 are provided on the upper part of the sealing tank 14. The air outlet 24 is distributed on the upper side of the second liquid inlet 23 and is located on the upper side of the sealing liquid surface. The second liquid outlet 23 is connected to the liquid inlet 21 through a connecting pipe 15 and a jet steam engine 16. The air outlet 24 is provided with an air pump 17. The output end of the air pump 17 is connected to the connecting pipe 15 through an aerator 18 and an air pipe 19. Metal supports 20 are provided at the upper end of the sealing tank 14 and on both sides thereof. The metal supports 20 are electrically connected to a current controller. A vibration assembly 200 is provided between the metal support 20 and the sealing tank 14.

[0038] By connecting the second liquid outlet 23 and the liquid inlet 21 through jet steam, part of the sealing liquid circulates and forms water vapor which enters the sealing tank 14. At the same time, the gas on the upper side of the liquid surface of the sealing tank 14 is extracted by the vacuum pump 17 and enters the connecting pipe 15 to form aeration. The gas follows the water vapor into the sealing liquid to maintain the temperature of the sealing liquid. At the same time, the water vapor makes it easier for water molecules to enter the anodized film for sealing. The setting of the second liquid outlet 23 and the liquid inlet 21 can accelerate the circulation of the sealing liquid and improve the rapid flow of air. At the same time, the air outlet 24 is arranged on the upper side of the liquid surface, so that its area forms a relatively low-pressure area, which further accelerates the rapid discharge of air in the gaps of the oxide film carried by the aerated air.

[0039] In addition, the vibration assembly 200 includes a base 201, a top seat 202, a voice coil motor 203 and a guide column and guide sleeve assembly 204 arranged between the base 201 and the top seat 202 and located on four feet. The top seat 202 is provided with a rubber pad 205, and the metal support 20 is arranged on the rubber pad 205. The voice coil motor 203 drives the top seat 202 to move along the guide column and guide sleeve assembly 204 to achieve vibration, which can better maintain the vibration amplitude and vibration frequency, thereby driving the aluminum profile on the connecting part 13 to form a regular movement, which is conducive to the discharge of dust on the surface, avoids the deposition of impurities, and ensures that the oxide film layer is flat and uniform after sealing.

[0040] Although the present invention has been particularly shown and described in conjunction with preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made to the present invention without departing from the spirit and scope of the invention as defined in the appended claims, and all such changes are within the scope of protection of the present invention.

Claims

1. A method for sealing the holes of a nickel-free zirconium salt oxide film on an aluminum alloy profile, characterized by: The following steps are involved: 1) The aluminum profile is suspended through the suspension assembly and subjected to surface pretreatment in sequence, including sandblasting, degreasing, water washing, alkali washing, water washing, pickling, and water washing; 2) The aluminum profile is suspended in an electrolytic cell by a suspension assembly for anodizing. The electrolyte in the electrolytic cell includes sodium hydroxide, sodium silicate, glycerol, disodium EDTA and deionized water; 3) After the aluminum profile treated in step 2 is rinsed in deionized water for 2 minutes, it is then ultrasonically shaken in anhydrous ethanol for 3 minutes to remove the residual electrolyte on the surface of the aluminum profile, and then air-dried; 4) The aluminum profile is suspended in the sealing tank using a suspension assembly. The aluminum electrode is used as the anode and the aluminum profile to be sealed is used as the cathode. A pulse current treatment is applied for 25 minutes. At the same time, the aluminum profile vibrates and the sealing liquid is circulated through a jet steam engine to aerate the sealing tank. The electrolyte temperature is maintained at 70°C to 110°C. The sealing liquid includes silicate, sodium hydroxide, silane, sodium fluorozirconate, potassium fluorozirconate, glacial acetic acid, and anionic surfactant. 5) The aluminum profile treated in step 4 is washed in deionized water, then ultrasonically cleaned in anhydrous ethanol, and dried.

2. The method for sealing the aluminum alloy profile with nickel-free zirconium salt oxide film according to claim 1, characterized in that: The pulse power supply constant voltage mode is adopted during the pulse power-on, and the voltage is 80V to 120V, the frequency is 130Hz to 180Hz, and the positive and negative pulse working ratio is 40% to 60%.

3. The method for sealing the aluminum alloy profile with a nickel-free zirconium salt oxide film according to claim 1, wherein: The anionic surfactant is lignin sulfonate.

4. The method for sealing the pores of the nickel-free zirconium salt oxide film of the aluminum alloy profile according to any one of claims 1 to 3, characterized in that: The suspension assembly includes a guide device distributed along the direction of the assembly line, a truss mounted on the guide device, a first drive device for driving the truss to move, a longitudinal guide device arranged on the truss, a hanger arranged on the longitudinal guide device, and a second drive device arranged on the truss for driving the hanger. Hook assemblies are provided at both lateral ends of the hanger, and the hook assembly is detachably provided with a connecting piece. Each of the aluminum profiles is hung on the connecting piece, and the connecting piece and the hanger are separated by relative movement along the longitudinal direction.

5. The method for sealing the pores of the nickel-free zirconium salt oxide film of the aluminum alloy profile according to claim 4, characterized in that: The first driving device includes a rack distributed along the direction of the guide device, a first driving motor arranged on the truss, and a driving gear arranged on the first driving motor and meshing with the rack.

6. The method for sealing the aluminum alloy profile with nickel-free zirconium salt oxide film according to claim 5, characterized in that: The second driving device includes a driving shaft and a driven shaft respectively arranged at the upper and lower ends of the truss, a second driving motor connected to the driving shaft, a driving sprocket arranged at the axial ends of the driving shaft, a driven sprocket arranged at the axial ends of the driven shaft, and a chain wound around the driving sprocket and the driven sprocket, and the hanger is fixedly connected to the chain.

7. The method for sealing the aluminum alloy profile with a nickel-free zirconium salt oxide film according to claim 6, wherein: The hook assembly includes a support plate fixed on the hanger, a connecting plate hinged to the hanger and located on the inner side of the support plate, an inclined plate fixedly connected to the connecting plate, and a hook portion provided at the free end of the inclined plate, and a spring is provided between the support plate and the connecting plate.

8. The method for sealing the pores of the nickel-free zirconium salt oxide film of the aluminum alloy profile according to claim 7, characterized in that: The angle between the inclined plate and the connecting plate is 45° to 60°.

9. The method for sealing the aluminum alloy profile with a nickel-free zirconium salt oxide film according to claim 4, wherein: A liquid inlet and a first liquid outlet are provided on the bottom surface of the sealing tank, and a second liquid outlet and an air outlet are provided on the upper part of the sealing tank. The air outlet is distributed on the upper side of the second liquid inlet and is located above the liquid level of the sealing liquid. The second liquid outlet is connected to the liquid inlet through a connecting pipe and a jet steam engine. The air outlet is provided with an air pump, and the output end of the air pump is connected to the connecting pipe through an aerator and an air pipe. Metal supports are provided at the upper end of the sealing tank and on both lateral sides. The metal supports are electrically connected to a current controller, and a vibration assembly is provided between the metal support and the sealing tank.

Images