Aluminum Alloy Coloring Treatment Process
The present disclosure provides a colored anodic aluminum alloy coloring treatment process for achieving the multi-color coloring treatment may be conducted on the surface of an aluminum alloy, and combining pigments and metals by physical coloring and chemical complexation. The process comprises the following steps: carrying out degreasing and decontamination the aluminum alloy, then carrying out alkalization treatment, and neutralizing alkalized substances; chemically polishing the aluminum alloy, neutralizing a chemical polishing compound, and performing anodic oxidation treatment to generate an aluminum oxide dielectric film layer with tiny holes in the surface of the aluminum alloy after anodic oxidation; and printing colorful process patterns on the surface of the aluminum alloy, and conducting air drying treatment and hole sealing treatment on the surface of the aluminum alloy.
The present invention relates to a metal treatment process, and more specifically, to a coloring process applied to metal process treatment.
In the prior art, conventional anodizing has the limitation of a single color. Conventional anodizing can only produce a single color, such as red, orange, yellow, green, cyan, blue, purple, black, and gray. Only one color on the positive workpiece can be reflected in the vision, which cannot meet the multi-color requirements of the product. There are also unstable colorings. After a period of use, there are process problems that are easy to decolor and change color; in view of this, the technical defects of a single color and easy aging and discoloration of the anodic oxidation coloring in this field have become technical problems to be solved urgently by those skilled in the art.
BRIEF SUMMARY OF THE INVENTIONThe technical purpose of the present invention is to overcome the difficulty of fixing color and the technical problems of single coloring in the anodic oxidation coloring in the surface treatment of aluminum alloy in the prior art, and to provide a colored anodic aluminum alloy coloring treatment process in order to achieve the technical purposes that multi-color coloring treatment can be conducted on the surface of an aluminum alloy, and pigments and metal are integrated through physical coloring and chemical complexing.
In order to achieve the above technical objectives, the technical solution of the present invention is:
The aluminum alloy coloring treatment process is characterized in that it includes the following steps:
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- a. Degreasing and decontaminating the surface of aluminum alloy;
- b. Alkalizing the surface of aluminum alloy and neutralizing the alkali;
- c. Chemically polishing the surface of aluminum alloy and neutralizing the chemical polishing compounds;
- d. Anodizing the surface of the aluminum alloy and neutralizing the anodic oxidation chemicals; after anodization, an aluminum oxide dielectric film with tiny holes is formed on the surface of the aluminum alloy;
- e. Printing color process patterns on the aluminum alloy surface by a printer using eco-solvent ink, and allowing the color ink to enter the tiny holes;
- f. Air-drying the surface of the aluminum alloy that has been printed with color patterns.
Further, after Step d and before Step e, a laser engraving machine is used to pre-process the edge of the pre-printed pattern on the aluminum alloy surface by laser edge sealing.
Further, the aluminum alloy coloring treatment process according to claim 1, characterized in that: after Step d and before Step e, a laser engraving machine is used to perform thermal radiation hole expansion treatment on the pre-printed pattern on the surface of the aluminum alloy.
Further, in Step a, a titanium material hanger with good alkali resistance and acid resistance and conductivity is used to place the aluminum alloy workpiece.
Further, in Step a, a 15%-30% nitric acid aqueous solution is used for cleaning, the nitric acid aqueous solution is heated to 60-70° C., and the workpiece is immersed for 3˜5 minutes to remove oil stains and wax stains on the surface of the workpiece.
Further, the tiny holes have a diameter of 0.01-0.03 μm.
Further, the color ink contains dye particles with a diameter of 0.0015-0.003 μm.
Anodizing the aluminum alloy surface for more than 45 minutes.
Sodium hydroxide: 200 g/L, sodium nitrate 50 g/L
The beneficial technical effects of the present invention are the dye is a dye that complexes metal ions; the temperature difference and negative pressure adsorption of the color ink can make the color ink adhere more firmly due to the thermal expansion and contraction of the hole, and evaporate the moisture while printing, drying, and pre-sealing edge can improve the accuracy of the pattern. The aluminum hydroxide through the porous layer is physically adsorbed; then chemically complexed to form colored metal salts; it becomes a part of the aluminum alloy. The color anode carries out special reaming technology and special membrane anode parameters on the anode film layer to consolidate the adhesion, compactness and wear resistance of the toner. Post-processing and coloring use a special printer and eco-solvent ink for coloring. After coloring, the holes are sealed again. The sealed holes are baked with a baking wire.
The specific embodiments of the present invention will be described in detail below with reference to specific examples, but the claims are not limited in any way.
In the present invention, a titanium hanger is used to fix the workpiece, and the titanium hanger has better alkali resistance and acid resistance and conductivity. A nitric acid solution with a ratio of 20 L nitric acid and 100 L water is used and heated to 60˜70° C. The workpiece is soaked for 3 to 5 minutes to remove oil and wax stains on the surface of the workpiece, and to degrease and decontaminate the surface of the aluminum alloy.
The surface of the aluminum alloy is alkalized and the alkali is neutralized; the alkali washing solution is prepared as follows: 200 g sodium hydroxide and 50 g sodium nitrate are dissolved in 1 liter of water; heated to 80˜90° C. to remove the natural oxide layer on the product surface, adjust the brightness of the product surface; or use sodium hydroxide: 380 g dissolved in 1 liter of water, heated to 80˜90° C., remove the natural oxide layer on the product surface, adjust the brightness of the product surface; after alkali washing, the solution for neutralizing alloy surface chemicals is prepared as follows: 1. Nitric acid weight percentage: 30%, 2. Chromic anhydride weight percentage: 5%, 3. Clear water weight percentage: 65%. Neutralize alkali washing at room temperature to remove compounds on the surface after alkali washing.
Perform chemical polishing on the aluminum alloy surface and neutralize the chemical polishing compound; the chemical polishing solution is formulated as follows: 1. Sulfuric acid (content 98%) is 16% by weight, 2. Phosphoric acid (content 85%) is 80% by weight, 3. The weight percentage of nitric acid (98%) is 4%. Soak the product at a temperature of 90˜110° C. to adjust the brightness of the product surface; the solution of the chemical polishing compound is formulated as follows: 1. The weight percentage of nitric acid is 30%, 2. The weight percentage of chromic anhydride is 5%, 3. The weight percentage of clear water is 65%; neutralize the chemical polishing compound at room temperature.
Anodize the surface of the aluminum alloy and neutralize the anodized chemicals. Perform anodization on the surface of the aluminum alloy for more than 45 minutes to form tiny holes on the surface of the aluminum alloy; the solution used for anodization: 150˜200 g sulfuric acid per liter of water and alumina 10˜15 g solution; the temperature of the solution is controlled at 18˜20° C., and anodizing treatment is carried out with a refrigerator, a rectifier, a lead plate+copper plate+PP tank fixed equipment. Approximately 7.7 billion nano-scale holes are anodized per square centimeter of aluminum surface, and the tiny holes are 0.01-0.03 μm in diameter. After anodic oxidation, a dielectric film of aluminum oxide with tiny holes is produced on the surface of the aluminum alloy; it is printed and dyed to become the only metal that can be dyed. Use 30% by weight of nitric acid, 5% by weight of chromic anhydride and 65% of clear water to neutralize the oxidizing acid solution, and expand the holes at room temperature.
The above procedures are achieved by ultrasonic equipment for ultrasonic treatment, which can obtain better washing and dye adhesion effects.
After anodization, the aluminum alloy surface is washed and air-dried. A laser engraving machine is used to pre-process the edge of the pre-printed pattern on the aluminum alloy surface by laser. During the implementation, the edge width is set as 0.01 mm-1 mm, and 0.1 mm is better. After sealing, the laser head of the laser engraving machine closes the holes at the edge of the pattern at a high temperature, and the color ink will not dye to the area outside the edge of the pattern during printing, which greatly improves the clarity and accuracy of the pattern. During implementation, the laser head of the laser engraving machine forms an angle of 20 degrees to 89 degrees with the surface of the aluminum alloy. The angle can be set to the inner side of the pattern edge. After the edge is sealed, the hole on the outer edge of the edge is inclined to the inner side of the pattern or inclined semi-open structure, which further restricts the extravasation of the color ink to the area outside the edge of the pattern and improves the accuracy of the color process pattern. In addition, a temperature difference process is applied to the present invention during implementation, and a laser in the engraving machine is used to perform thermal radiation hole expansion treatment on the aluminum alloy surface at 60° C. to 200° C. After the thermal radiation hole expansion treatment, the printing is performed. The color ink can be at room temperature. It can also further reduce the temperature of the color ink. The temperature of the color ink is reduced from −10° C. to +20° C. When the color ink enters the hole during printing, the material and air rapidly shrink, forming a tiny negative pressure adsorption force. The color ink is better absorbed into the hole and further complexed with the aluminum alloy. Since the temperature of the aluminum alloy rises under the thermal radiation of the laser, the water in the color ink will quickly evaporate when encountering the color ink, forming thermal expansion and cooling. The rapid drying process with firm shrinkage absorption and drying at the same time avoids the need to print multiple sides of the ring-shaped workpiece, and the ink flow caused by the rapid overturn of the ring-shaped workpiece and the printing ink is not dry, which will affect the visual effect of the pattern.
During implementation, the eco-solvent ink is complex ion nano eco-solvent color ink. More preferably, the ink is water-based eco-solvent ink, which can pass the oil-based perfume test. In the present invention, the main component of the eco-solvent ink is an organic solvent, and ester and ketone solvents are used to fuse the aluminum alloy during the process of combining with the aluminum alloy, and the colorant in the eco-solvent ink is closely combined with the aluminum alloy. Eco-solvent ink does not require the medium to be covered with a coating, and it can meet the requirements of high-speed printing through a temperature difference process. The printer will print a color pattern on the surface of the aluminum alloy, and form a color pattern attached to the surface of the aluminum alloy by reacting the complex anion in the weak solvent with the cation of the aluminum alloy. It is firm, non-marking and durable, and the items are suitable for historical collection.
The color ink contains dye particles with a diameter of 0.0015-0.003 μm. The color ink enters the tiny holes; the aluminum alloy surface with the color pattern printed is air-dried. The ambient temperature is controlled below 26° C., and the air knife is used to cut the water for 30 minutes.
In the present invention, the dye is a dye that complexes metal ions; the aluminum hydroxide through the porous layer is physically adsorbed; it is chemically complexed to form colored metal salts; it becomes a part of the aluminum alloy; the color anode carries out special reaming technology and special membrane anode parameters on the anode film layer to consolidate the adhesion, compactness and wear resistance of the toner. Post-processing and coloring use a special printer and eco-solvent ink for coloring. After coloring, the holes are sealed again. The sealed holes are baked with a baking wire.
Claims
1. The aluminum alloy coloring treatment process is characterized in that it includes the following steps:
- a. Degreasing and decontaminating the surface of aluminum alloy;
- b. Alkalizing the surface of aluminum alloy and neutralizing the alkali;
- c. Chemically polishing the surface of aluminum alloy and neutralizing the chemical polishing compounds;
- d. Anodizing the surface of the aluminum alloy and neutralizing the anodic oxidation chemicals; after anodization, an aluminum oxide dielectric film with tiny holes is formed on the surface of the aluminum alloy;
- e. Printing color process patterns on the aluminum alloy surface by a printer using water-based eco-solvent ink, and allowing the color ink to enter the tiny holes;
- f. Air-drying the surface of the aluminum alloy that has been printed with color patterns.
2. The aluminum alloy coloring treatment process according to claim 1, characterized in that: after Step d and before Step e, a laser engraving machine is used to pre-process the edge of the pre-printed pattern on the aluminum alloy surface by laser edge sealing.
3. The aluminum alloy coloring treatment process according to claim 1, characterized in that: after Step d and before Step e, a laser engraving machine is used to perform thermal radiation hole expansion treatment on the pre-printed pattern on the surface of the aluminum alloy.
4. The aluminum alloy coloring treatment process according to claim 1, characterized in that: in Step a, a titanium material hanger with good alkali resistance and acid resistance and conductivity is used to place the aluminum alloy workpiece.
5. The aluminum alloy coloring treatment process according to claim 1, characterized in that: in Step a, a 15%-30% nitric acid aqueous solution is used for cleaning, the nitric acid aqueous solution is heated to 60-70° C., and the workpiece is immersed for 3˜5 minutes to remove oil stains and wax stains on the surface of the workpiece.
6. The aluminum alloy coloring treatment process according to claim 1, characterized in that: the tiny holes have a diameter of 0.01-0.03 μm.
7. The aluminum alloy coloring treatment process according to claim 1, characterized in that: the color ink contains dye particles with a diameter of 0.0015-0.003 μm.
8. The aluminum alloy coloring treatment process according to claim 1, characterized in that: in Step d, the surface of the aluminum alloy is anodized for more than 45 minutes.
9. The aluminum alloy coloring treatment process according to claim 1, characterized in that: in Step e, the eco-solvent ink is an aqueous ink.
