阅读说明：本技术 一种铝合金染色添加剂及染色方法 (Aluminum alloy dyeing additive and dyeing method ) 是由 况金权 于 2020-12-18 设计创作，主要内容包括：本发明涉及铝合金技术领域,具体涉及一种铝合金染色添加剂及染色方法。所述铝合金染色添加剂包括如下重量份的原料硫酸镍30-35份、硫酸亚锡8-12份、硫酸18-22份、着色稳定剂16-20份、增效助剂13-18份。本发明的染色添加剂使用于铝合金染色,可提高染色效率及均匀性,提高染色效果和产品良率,解决染色过程出现的流色和异色等问题,延长着色液的使用时间,使铝合金具有良好的外观效果,耐用性好,使用寿命长。利用铝合金染色前处理剂的铝合金染色前处理方法操作简便,易于控制,可显著提高染色效率及均匀性,提高染色效果和产品良率,利于得到颜色均匀,外观效果佳的铝合金染色工件,适用于工业化大生产。(The invention relates to the technical field of aluminum alloy, in particular to an aluminum alloy dyeing additive and a dyeing method. The aluminum alloy dyeing additive comprises, by weight, 30-35 parts of raw material nickel sulfate, 8-12 parts of stannous sulfate, 18-22 parts of sulfuric acid, 16-20 parts of a dyeing stabilizer and 13-18 parts of a synergistic additive. The dyeing additive disclosed by the invention is used for dyeing the aluminum alloy, can improve the dyeing efficiency and uniformity, improve the dyeing effect and the product yield, solve the problems of color bleeding, heterochrosis and the like in the dyeing process, prolong the service time of the coloring liquid, and enable the aluminum alloy to have a good appearance effect, good durability and long service life. The aluminum alloy dyeing pretreatment method using the aluminum alloy dyeing pretreatment agent is simple and convenient to operate and easy to control, can remarkably improve dyeing efficiency and uniformity, improves dyeing effect and product yield, is beneficial to obtaining aluminum alloy dyeing workpieces with uniform color and good appearance effect, and is suitable for industrial mass production.)

1. An aluminum alloy dyeing additive is characterized in that: the feed comprises the following raw materials in parts by weight: 30-35 parts of nickel sulfate, 8-12 parts of stannous sulfate, 18-22 parts of sulfuric acid, 16-20 parts of a coloring stabilizer and 13-18 parts of a synergistic additive.

2. An aluminum alloy coloring additive according to claim 1, wherein: the coloring stabilizer is at least one of phosphotungstic acid, sodium tungstate and tungstic acid.

3. An aluminum alloy coloring additive according to claim 2, wherein: each part of the synergistic auxiliary comprises the following raw materials in parts by weight: 15-20 parts of polyhydroxy organic acid, 4-7 parts of p-diphenol monomethyl ether, 5-8 parts of fatty alcohol-polyoxyethylene ether and 3-5 parts of mannitol.

4. An aluminum alloy dyeing method is characterized in that: the method comprises the following steps:

(1) taking an aluminum alloy workpiece, degreasing the aluminum alloy workpiece, and washing the aluminum alloy workpiece after degreasing and deoiling;

(2) chemical polishing is carried out on the aluminum alloy workpiece by adopting chemical polishing solution, water washing is carried out after polishing, and then insoluble metal oxide is removed;

(3) carrying out anodic oxidation on the aluminum alloy workpiece in an anodic oxidation bath solution to form an anodic oxidation film on the metal surface; washing the anodized aluminum alloy workpiece with water to remove residual anodic oxidation bath solution;

(4) carrying out dyeing pretreatment on the aluminum alloy workpiece with the residual anodic oxidation bath solution removed by adopting a dyeing pretreatment agent;

(5) placing the aluminum alloy workpiece treated by the dyeing pretreatment agent in an electrolytic bath for electrolytic dyeing, wherein the dyeing additive as defined in any one of claims 1 to 3 is added into the bath solution of the electrolytic bath; the concentration of the dyeing additive in the electrolytic coloring liquid is 90-120 g/L;

(6) and sealing the holes of the dyed aluminum alloy workpiece to obtain a finished aluminum alloy workpiece product.

5. The aluminum alloy dyeing pretreatment method according to claim 4, characterized in that: in the step (3), sulfuric acid and A are adopted³⁺Carrying out anodic oxidation on the aluminum alloy workpiece by using the solution; the concentration of the sulfuric acid is 140-180g/L, and the sulfuric acid and A³⁺The concentration of the solution is 8-15g/L。

6. The aluminum alloy dyeing pretreatment method according to claim 4, characterized in that: in the step (3), the temperature of anodic oxidation is 18-22 ℃, the voltage is 18-24V, and the anodic oxidation time is 25-45 min.

7. The aluminum alloy dyeing pretreatment method according to claim 4, characterized in that: in the step (5), the temperature of electrolytic dyeing is 18-22 ℃, the voltage is 15-20V, and the dyeing time is 3-8 min.

8. The aluminum alloy dyeing pretreatment method according to claim 4, characterized in that: in the step (5), the concentration of the dyeing additive in the electrolytic coloring liquid is 90-120 g/L;

the aluminum alloy dyeing pretreatment method according to claim 4, characterized in that: in the step (6), a nickel acetate solution is adopted for hole sealing, and the concentration of the nickel acetate solution is 5.5-6.5 g/L.

9. The aluminum alloy dyeing pretreatment method according to claim 4, characterized in that: in the step (6), the temperature of the hole sealing treatment is 95-100 ℃.

Technical Field

The invention relates to the technical field of aluminum alloy, in particular to an aluminum alloy dyeing additive and a dyeing method.

Background

Along with the development of society and the progress of science and technology, aluminum alloy is increasingly well applied, and the prior art usually adopts an anodic oxidation process and a dyeing process for treatment so as to improve the durability and the decorative effect of aluminum alloy products. However, in the dyeing process of the existing dyeing process, the conditions of uneven distribution of dyeing agents, reduced dyeing capability and the like are often caused, so that the product has the defects of flow marks, mottles and the like, the product is easy to flow colors and heterochromatic colors, the dyeing effect is not high, the dyeing effect is not good, the product yield and the durability are affected, and further improvement is needed.

Disclosure of Invention

In order to overcome the defects and shortcomings in the prior art, the invention aims to provide the aluminum alloy dyeing additive which is used for dyeing the aluminum alloy, can improve the dyeing efficiency and uniformity, improve the dyeing effect and the product yield, solve the problems of bleeding, abnormal color and the like in the dyeing process, and enable the aluminum alloy to have good appearance effect, good durability and long service life.

The invention aims to provide an aluminum alloy dyeing method using an aluminum alloy dyeing additive, which is simple and convenient to operate, easy to control, capable of remarkably improving dyeing efficiency and uniformity, improving dyeing effect and product yield, beneficial to obtaining an aluminum alloy dyeing workpiece with uniform color and good appearance effect, and suitable for industrial mass production.

The purpose of the invention is realized by the following technical scheme: an aluminum alloy dyeing additive comprises the following raw materials in parts by weight: 30-35 parts of nickel sulfate, 8-12 parts of stannous sulfate, 18-22 parts of sulfuric acid, 16-20 parts of a coloring stabilizer and 13-18 parts of a synergistic additive.

Further, the coloring stabilizer is at least one of phosphotungstic acid, sodium tungstate and tungstic acid.

According to the aluminum alloy dyeing additive disclosed by the invention, the nickel sulfate, the stannous sulfate, the sulfuric acid, the coloring stabilizer and the synergistic additive are compounded, so that the additive is used for dyeing the aluminum alloy, the dyeing efficiency and uniformity can be improved, the dyeing effect and the product yield are improved, the problems of bleeding, abnormal color and the like in the dyeing process are solved, the service life of the coloring liquid is prolonged, the aluminum alloy has a good appearance effect, the durability is good, and the service life is long.

Further, each part of the functional auxiliary agent comprises the following raw materials in parts by weight: 15-20 parts of polyhydroxy organic acid, 4-7 parts of p-diphenol monomethyl ether, 5-8 parts of fatty alcohol-polyoxyethylene ether and 3-5 parts of mannitol. The synergistic additive is beneficial to preventing the coloring liquid from generating precipitation, can be used for dyeing the aluminum alloy workpiece with enough complexity, enables the dyeing to be more uniform, improves the dyeing stability, prevents the occurrence of bad phenomena such as bleeding, abnormal color and the like, has high dyeing efficiency and improves the corrosion resistance of the aluminum alloy workpiece. The polyhydroxy organic acid is at least one of 2, 3-dihydroxy succinic acid, maleic acid and citric acid.

The invention also provides a dyeing method of the aluminum alloy, which comprises the following steps:

(1) taking an aluminum alloy workpiece, degreasing the aluminum alloy workpiece, and washing the aluminum alloy workpiece after degreasing and deoiling;

(2) chemical polishing is carried out on the aluminum alloy workpiece by adopting chemical polishing solution, water washing is carried out after polishing, and then insoluble metal oxide is removed;

(3) carrying out anodic oxidation on the aluminum alloy workpiece in an anodic oxidation bath solution to form an anodic oxidation film on the metal surface; washing the anodized aluminum alloy workpiece with water to remove residual anodic oxidation bath solution;

(4) carrying out dyeing pretreatment on the aluminum alloy workpiece with the residual anodic oxidation bath solution removed by adopting a dyeing pretreatment agent;

(5) placing the aluminum alloy workpiece treated by the dyeing pretreatment agent in an electrolytic cell for electrolytic dyeing, wherein the dyeing additive is added into the bath solution of the electrolytic cell; the concentration of the dyeing additive in the electrolytic coloring liquid is 90-120 g/L;

(6) and sealing the holes of the dyed aluminum alloy workpiece to obtain a finished aluminum alloy workpiece product.

Further, in the step (3), sulfuric acid and A are adopted³⁺Carrying out anodic oxidation on the aluminum alloy workpiece by using the solution; the concentration of the sulfuric acid is 140-180g/L, and the sulfuric acid and A³⁺The concentration of the solution is 8-15 g/L. In the step (3), the temperature of anodic oxidation is 18-22 ℃, the voltage is 18-24V, and the anodic oxidation time is 25-45 min.

Further, in the step (5), the temperature of electrolytic dyeing is 18-22 ℃, the voltage is 15-20V, and the dyeing time is 3-8 min. The concentration of the dyeing additive in the electrolytic coloring liquid is 90-120 g/L;

further, in the step (6), a nickel acetate solution is used for hole sealing, wherein the concentration of the nickel acetate solution is 5.5-6.5g/L, and the pH value is 5.3-6. The temperature of the hole sealing treatment is 95-100 ℃. By adopting the process, the corrosion resistance and the pollution resistance of the aluminum alloy are improved, the dye after dyeing is prevented from overflowing, and the dyeing efficiency and the dyeing uniformity are improved.

Further, in the step (4), the aluminum alloy dyeing pretreatment agent comprises the following raw materials in parts by weight: 25-30 parts of citric acid, 6-12 parts of salicylic acid, 3-5 parts of sodium citrate, 2-4 parts of potassium sodium tartrate, 0.5-1.5 parts of surfactant and 1-2 parts of functional assistant.

Further, the surfactant is at least one of sodium monoglyceride disulfate, sodium lauryl sulfate and sodium diisooctyl succinate sulfonate.

According to the invention, the aluminum alloy dyeing pretreatment agent is prepared by compounding citric acid, salicylic acid, sodium citrate, potassium sodium tartrate, the surfactant and the functional assistant, so that the poor dyeing such as spots and the like caused by residual acid at surface holes and defects introduced in the anodic oxidation process and the process before the anodic oxidation of the aluminum alloy workpiece can be prevented, the dyeing efficiency and uniformity can be remarkably improved, the dyeing effect and product yield can be improved, the color blurring problem during dyeing can be reduced, and the aluminum alloy dyeing workpiece with uniform color and good appearance effect can be obtained.

Further, each part of the functional auxiliary agent comprises the following raw materials in parts by weight: 7-10 parts of polyvinyl alcohol, 4-7 parts of p-diphenol monomethyl ether, 5-8 parts of glycerol and 3-5 parts of polydimethylsiloxane.

By adopting the raw materials, the invention is beneficial to reducing the corrosion effect on the surface of the aluminum alloy and effectively preventing the surface of the aluminum alloy from generating defects, and the elastic film of bubbles can be damaged in the dyeing pretreatment process, so that the invention has good bubble inhibiting effect, is beneficial to improving the dyeing efficiency and uniformity and improving the dyeing effect and the product yield.

Further, the aluminum alloy dyeing pretreatment method of the aluminum alloy dyeing pretreatment agent comprises the following steps:

(A1) placing the anodized aluminum alloy workpiece in a pretreating agent for preliminary treatment, and then washing with water;

(A2) and (3) pre-treating the pre-treated aluminum alloy workpiece in an aluminum alloy dyeing pretreatment agent, and then washing to obtain the aluminum alloy workpiece subjected to dyeing pretreatment.

Further, in the step (A1), ultrasonic waves are adopted for preliminary treatment, the preliminary treatment temperature is 30-40 ℃, and the preliminary treatment time is 60-150 s. The ultrasonic frequency is 50-70 kHz.

Further, in the step (a 1), the pretreating agent comprises the following raw materials in parts by weight: 20-30 parts of sodium bicarbonate, 4-7 parts of mannitol and 900 parts of deionized water.

According to the invention, the sodium bicarbonate, the mannitol and the deionized water are compounded to prepare the pretreating agent, so that residual acid at surface holes and defects introduced in the anodic oxidation process and the working procedure before the anodic oxidation of the aluminum alloy workpiece is removed, the removing efficiency is high, the residual acid is removed more thoroughly, the sodium bicarbonate can be matched with the mannitol, the corrosion to the surface of the aluminum alloy workpiece is greatly reduced, aluminum sulfate crystals formed on the surface of the aluminum alloy workpiece by oxidation when the aluminum ion content is higher in an anodic oxidation tank can be effectively removed, and the adverse effects of uneven dyeing, generation of corrosion points, flowering and the like in the subsequent dyeing process are prevented. The dyeing pretreatment agent can be used for the pretreatment of aluminum alloy anode oxidation dyeing, can obviously improve the dyeing efficiency and uniformity, and improves the dyeing effect and the product yield. The aluminum alloy dyeing pretreatment method using the aluminum alloy dyeing pretreatment agent is simple and convenient to operate and easy to control, can remarkably improve dyeing efficiency and uniformity, improves dyeing effect and product yield, is beneficial to obtaining aluminum alloy dyeing workpieces with uniform color and good appearance effect, and is suitable for industrial mass production.

Further, in the step (A2), the temperature of pretreatment by ultrasonic is 35-45 ℃, and the pretreatment time is 2-5 min. The ultrasonic frequency is 40-50 kHz. According to the invention, the dyeing pretreatment is carried out by adopting ultrasonic waves, and the steps are strictly controlled, so that the efficiency of the aluminum alloy dyeing pretreatment is improved, the pretreatment effect is improved, and the problems of uneven dyeing, corrosion spots, flowering and the like of the aluminum alloy workpiece in the subsequent dyeing process are prevented.

The invention has the beneficial effects that: the dyeing additive disclosed by the invention is used for dyeing the aluminum alloy, can improve the dyeing efficiency and uniformity, improve the dyeing effect and the product yield, can be used for treating an aluminum alloy workpiece with a relatively complex appearance structure, solves the problems of color bleeding, heterochrosis and the like in the dyeing process, prolongs the service life of the coloring liquid, and enables the aluminum alloy to have a good appearance effect, good durability and long service life. The aluminum alloy dyeing pretreatment method using the aluminum alloy dyeing pretreatment agent is simple and convenient to operate and easy to control, can remarkably improve dyeing efficiency and uniformity, improves dyeing effect and product yield, is beneficial to obtaining aluminum alloy dyeing workpieces with uniform color and good appearance effect, and is suitable for industrial mass production.

Detailed Description

The present invention will be further described with reference to the following examples for facilitating understanding of those skilled in the art, and the description of the embodiments is not intended to limit the present invention.

Example 1

In this embodiment, the aluminum alloy dyeing additive comprises the following raw materials in parts by weight: 32 parts of nickel sulfate, 10 parts of stannous sulfate, 20 parts of sulfuric acid, 18 parts of a coloring stabilizer and 16 parts of a synergistic auxiliary agent.

Further, the coloring stabilizer is composed of phosphotungstic acid and tungstic acid according to the weight ratio of 1: 1.

Further, each part of the functional auxiliary agent comprises the following raw materials in parts by weight: 16 parts of polyhydroxy organic acid, 5 parts of p-diphenol monomethyl ether, 7 parts of fatty alcohol-polyoxyethylene ether and 4 parts of mannitol.

A method for dyeing aluminum alloy comprises the following steps:

(1) taking an aluminum alloy workpiece, degreasing the aluminum alloy workpiece, and washing the aluminum alloy workpiece after degreasing and deoiling;

(2) chemical polishing is carried out on the aluminum alloy workpiece by adopting chemical polishing solution, water washing is carried out after polishing, and then insoluble metal oxide is removed;

(3) carrying out anodic oxidation on the aluminum alloy workpiece in an anodic oxidation bath solution to form an anodic oxidation film on the metal surface; washing the anodized aluminum alloy workpiece with water to remove residual anodic oxidation bath solution;

(4) carrying out dyeing pretreatment on the aluminum alloy workpiece with the residual anodic oxidation bath solution removed by adopting a dyeing pretreatment agent;

(5) placing the aluminum alloy workpiece treated by the dyeing pretreatment agent in an electrolytic cell for electrolytic dyeing, wherein the dyeing additive is added into the bath solution of the electrolytic cell; the concentration of the dyeing additive in the electrolytic coloring liquid is 90-120 g/L;

(6) and sealing the holes of the dyed aluminum alloy workpiece to obtain a finished aluminum alloy workpiece product.

Further, in the step (3), sulfuric acid and A are adopted³⁺Carrying out anodic oxidation on the aluminum alloy workpiece by using the solution; the concentration of the sulfuric acid is 160g/L, and the sulfuric acid and A³⁺The concentration of the solution was 10 g/L. In the step (3), the temperature of anodic oxidation is 20 ℃, the voltage is 22V, and the anodic oxidation time is 35 min.

Further, in the step (5), the temperature of electrolytic dyeing is 20 ℃, the voltage is 17V, and the dyeing time is 5 min. The concentration of the dyeing additive in the electrolytic coloring liquid is 95 g/L;

further, in the step (6), a nickel acetate solution is used for hole sealing, and the concentration of the nickel acetate solution is 5.6 g/L. The temperature of the hole sealing treatment was 98 ℃.

Further, in the step (4), the aluminum alloy dyeing pretreatment agent comprises the following raw materials in parts by weight: 28 parts of citric acid, 8 parts of salicylic acid, 4 parts of sodium citrate, 3 parts of potassium sodium tartrate, 1 part of surfactant and 1.5 parts of functional assistant.

Further, the surfactant is composed of sodium monoglyceride disulfate and sodium lauryl sulfate according to a weight ratio of 1: 2.

Further, each part of the functional auxiliary agent comprises the following raw materials in parts by weight: 8 parts of polyvinyl alcohol, 3 parts of sodium acetate, 6 parts of glycerol and 4 parts of polydimethylsiloxane.

The aluminum alloy dyeing pretreatment method adopting the aluminum alloy dyeing pretreatment agent comprises the following steps:

(A1) placing the anodized aluminum alloy workpiece in a pretreating agent for preliminary treatment, and then washing with water;

(A2) and (3) pre-treating the pre-treated aluminum alloy workpiece in an aluminum alloy dyeing pretreatment agent, and then washing to obtain the aluminum alloy workpiece subjected to dyeing pretreatment. The aluminum alloy workpiece is to be dyed.

Further, in the step (a 1), the preliminary treatment is performed by using ultrasonic waves, the preliminary treatment temperature is 35 ℃, and the preliminary treatment time is 120 seconds. The ultrasonic frequency was 60 kHz.

Further, in the step (a 1), the pretreating agent comprises the following raw materials in parts by weight: 25 parts of sodium bicarbonate, 6 parts of mannitol and 850 parts of deionized water.

Further, in the step (a 2), the temperature of the pretreatment by ultrasonic waves was 40 ℃, and the pretreatment time was 4 min. The ultrasonic frequency was 45 kHz.

Example 2

In this embodiment, the aluminum alloy dyeing additive comprises the following raw materials in parts by weight: 30 parts of nickel sulfate, 8 parts of stannous sulfate, 18 parts of sulfuric acid, 16 parts of a coloring stabilizer and 13 parts of a synergistic additive.

Further, the coloring stabilizer is composed of phosphotungstic acid and sodium tungstate according to the weight ratio of 1: 1.

Further, each part of the functional auxiliary agent comprises the following raw materials in parts by weight: 15 parts of polyhydroxy organic acid, 4 parts of p-diphenol monomethyl ether, 5 parts of fatty alcohol-polyoxyethylene ether and 3 parts of mannitol.

A method for dyeing aluminum alloy comprises the following steps:

(1) taking an aluminum alloy workpiece, degreasing the aluminum alloy workpiece, and washing the aluminum alloy workpiece after degreasing and deoiling;

(2) chemical polishing is carried out on the aluminum alloy workpiece by adopting chemical polishing solution, water washing is carried out after polishing, and then insoluble metal oxide is removed;

(3) carrying out anodic oxidation on the aluminum alloy workpiece in an anodic oxidation bath solution to form an anodic oxidation film on the metal surface; washing the anodized aluminum alloy workpiece with water to remove residual anodic oxidation bath solution;

(4) carrying out dyeing pretreatment on the aluminum alloy workpiece with the residual anodic oxidation bath solution removed by adopting a dyeing pretreatment agent;

(5) placing the aluminum alloy workpiece treated by the dyeing pretreatment agent in an electrolytic cell for electrolytic dyeing, wherein the dyeing additive is added into the bath solution of the electrolytic cell; the concentration of the dyeing additive in the electrolytic coloring liquid is 90-120 g/L;

(6) and sealing the holes of the dyed aluminum alloy workpiece to obtain a finished aluminum alloy workpiece product.

Further, in the step (3), sulfuric acid and A are adopted³⁺Carrying out anodic oxidation on the aluminum alloy workpiece by using the solution; the concentration of the sulfuric acid is 140g/L, and the sulfuric acid and A³⁺The concentration of the solution was 8 g/L. In the step (3), the temperature of anodic oxidation is 1 ℃, the voltage is 18V, and the anodic oxidation time is 45 min.

Further, in the step (5), the temperature of electrolytic dyeing is 18 ℃, the voltage is 15, and the dyeing time is 8 min. The concentration of the dyeing additive in the electrolytic coloring liquid is 9 g/L;

further, in the step (6), a nickel acetate solution is used for hole sealing, and the concentration of the nickel acetate solution is 5.8 g/L. The temperature of the hole sealing treatment is 100 ℃.

Further, in the step (4), the aluminum alloy dyeing pretreatment agent comprises the following raw materials in parts by weight: 25 parts of citric acid, 6 parts of salicylic acid, 3 parts of sodium citrate, 2 parts of potassium sodium tartrate, 0.5 part of surfactant and 1 part of functional assistant.

Further, the surfactant sodium lauryl sulfate and the sodium diisooctyl succinate sulfonate are mixed according to the weight ratio of 1: 2.

Further, each part of the functional auxiliary agent comprises the following raw materials in parts by weight: 8 parts of polyvinyl alcohol, 3 parts of sodium acetate, 6 parts of glycerol and 4 parts of polydimethylsiloxane.

The aluminum alloy dyeing pretreatment method adopting the aluminum alloy dyeing pretreatment agent comprises the following steps:

(A1) placing the anodized aluminum alloy workpiece in a pretreating agent for preliminary treatment, and then washing with water;

(A2) and (3) pre-treating the pre-treated aluminum alloy workpiece in an aluminum alloy dyeing pretreatment agent, and then washing to obtain the aluminum alloy workpiece subjected to dyeing pretreatment.

Further, in the step (a 1), ultrasonic waves are used for preliminary treatment, the preliminary treatment temperature is 30 ℃, and the preliminary treatment time is 150 seconds. The ultrasonic frequency was 50 kHz.

Further, in the step (a 1), the pretreating agent comprises the following raw materials in parts by weight: 20 parts of sodium bicarbonate, 4 parts of mannitol and 800 parts of deionized water.

Further, in the step (a 2), the temperature of the pretreatment by ultrasonic waves was 35 ℃, and the pretreatment time was 5 min. The ultrasonic frequency was 40 kHz.

Example 3

The aluminum alloy dyeing additive in the embodiment comprises the following raw materials in parts by weight: 35 parts of nickel sulfate, 812 parts of stannous sulfate, 22 parts of sulfuric acid, 20 parts of a coloring stabilizer and 18 parts of a synergistic additive.

Further, the coloring stabilizer is composed of sodium tungstate and tungstic acid according to the weight ratio of 1: 0.6.

Further, each part of the functional auxiliary agent comprises the following raw materials in parts by weight: 20 parts of polyhydroxy organic acid, 7 parts of p-diphenol monomethyl ether, 8 parts of fatty alcohol-polyoxyethylene ether and 5 parts of mannitol.

A method for dyeing aluminum alloy comprises the following steps:

(1) taking an aluminum alloy workpiece, degreasing the aluminum alloy workpiece, and washing the aluminum alloy workpiece after degreasing and deoiling;

(2) chemical polishing is carried out on the aluminum alloy workpiece by adopting chemical polishing solution, water washing is carried out after polishing, and then insoluble metal oxide is removed;

(3) carrying out anodic oxidation on the aluminum alloy workpiece in an anodic oxidation bath solution to form an anodic oxidation film on the metal surface; washing the anodized aluminum alloy workpiece with water to remove residual anodic oxidation bath solution;

(4) carrying out dyeing pretreatment on the aluminum alloy workpiece with the residual anodic oxidation bath solution removed by adopting a dyeing pretreatment agent;

(5) placing the aluminum alloy workpiece treated by the dyeing pretreatment agent in an electrolytic cell for electrolytic dyeing, wherein the dyeing additive is added into the bath solution of the electrolytic cell; the concentration of the dyeing additive in the electrolytic coloring liquid is 120 g/L;

(6) and sealing the holes of the dyed aluminum alloy workpiece to obtain a finished aluminum alloy workpiece product.

Further, in the step (3), sulfuric acid and A are adopted³⁺Carrying out anodic oxidation on the aluminum alloy workpiece by using the solution; the concentration of the sulfuric acid is 180g/L, and the sulfuric acid and A³⁺The concentration of the solution was 15 g/L. In the step (3), the temperature of anodic oxidation is 22 ℃, the voltage is 24V, and the anodic oxidation time is 25 min.

Further, in the step (5), the temperature of electrolytic dyeing is 22 ℃, the voltage is 20V, and the dyeing time is 3 min. The concentration of the dyeing additive in the electrolytic coloring liquid is 120 g/L;

further, in the step (6), a nickel acetate solution is used for hole sealing, and the concentration of the nickel acetate solution is 6.5 g/L. The temperature of the hole sealing treatment was 95 ℃.

Further, in the step (4), the aluminum alloy dyeing pretreatment agent comprises the following raw materials in parts by weight: 25-30 parts of citric acid, 12 parts of salicylic acid, 5 parts of sodium citrate, 4 parts of potassium sodium tartrate, 1.5 parts of surfactant and 2 parts of functional assistant.

Further, the surfactant is composed of sodium monoglyceride disulfate and sodium diisooctyl succinate sulfonate according to the weight ratio of 1: 2.

Further, each part of the functional auxiliary agent comprises the following raw materials in parts by weight: 10 parts of polyvinyl alcohol, 4 parts of sodium acetate, 8 parts of glycerol and 5 parts of polydimethylsiloxane.

The aluminum alloy dyeing pretreatment method adopting the aluminum alloy dyeing pretreatment agent comprises the following steps:

(1) placing the anodized aluminum alloy workpiece in a pretreating agent for preliminary treatment, and then washing with water;

(2) and (3) pre-treating the pre-treated aluminum alloy workpiece in an aluminum alloy dyeing pretreatment agent, and then washing to obtain the aluminum alloy workpiece subjected to dyeing pretreatment.

Further, in the step (a 1), the preliminary treatment is performed by using ultrasonic waves, the preliminary treatment temperature is 40 ℃, and the preliminary treatment time is 60 seconds. The ultrasonic frequency was 50 kHz.

Further, in the step (a 1), the pretreating agent comprises the following raw materials in parts by weight: 20-30 parts of sodium bicarbonate, 4-7 parts of mannitol and 900 parts of deionized water.

Further, in the step (A2), the temperature of pretreatment by ultrasonic is 35-45 ℃ and the pretreatment time is 2 min. The ultrasonic frequency was 50 kHz.

Example 4

In this embodiment, the aluminum alloy dyeing additive comprises the following raw materials in parts by weight: 33 parts of nickel sulfate, 9 parts of stannous sulfate, 19 parts of sulfuric acid, 18 parts of a coloring stabilizer and 15 parts of a synergistic additive.

Further, the coloring stabilizer is at least one of phosphotungstic acid, sodium tungstate and tungstic acid.

Further, each part of the functional auxiliary agent comprises the following raw materials in parts by weight: 16 parts of polyhydroxy organic acid, 5 parts of p-diphenol monomethyl ether, 4 parts of fatty alcohol-polyoxyethylene ether and 3.5 parts of mannitol.

Further, in the step (4), the aluminum alloy dyeing pretreatment agent comprises the following raw materials in parts by weight: 26 parts of citric acid, 10 parts of salicylic acid, 4 parts of sodium citrate, 3 parts of potassium sodium tartrate, 1.2 parts of surfactant and 1.5 parts of functional assistant.

Further, each part of the functional auxiliary agent comprises the following raw materials in parts by weight: 9 parts of polyvinyl alcohol, 3 parts of sodium acetate, 6 parts of glycerol and 4 parts of polydimethylsiloxane.

The aluminum alloy dyeing pretreatment method adopting the aluminum alloy dyeing pretreatment agent comprises the following steps:

(1) placing the anodized aluminum alloy workpiece in a pretreating agent for preliminary treatment, and then washing with water;

(2) and (3) pre-treating the pre-treated aluminum alloy workpiece in an aluminum alloy dyeing pretreatment agent, and then washing to obtain the aluminum alloy workpiece subjected to dyeing pretreatment.

The rest of this embodiment is the same as embodiment 1, and is not described herein again.

Comparative example 1

This comparative example differs from example 1 in that: in the step (4), the aluminum alloy dyeing pretreatment agent comprises the following raw materials in parts by weight: 36 parts of citric acid, 7 parts of sodium citrate and 1 part of surfactant. The aluminum alloy dyeing pretreatment method adopting the aluminum alloy dyeing pretreatment agent comprises the following steps: and (3) pre-treating the pre-treated aluminum alloy workpiece in an aluminum alloy dyeing pretreatment agent, and then washing to obtain the aluminum alloy workpiece subjected to dyeing pretreatment. The temperature for pretreatment by ultrasonic wave is 40 ℃, and the pretreatment time is 4 min. The ultrasonic frequency was 45 kHz.

Comparative example 2

This comparative example differs from example 1 in that: the dyeing method of this comparative example does not include step (4).

Comparative example 3

This comparative example differs from example 1 in that: the aluminum alloy dyeing additive of the present comparative example does not contain a builder.

5052 aluminum alloy workpieces, which were provided with blind holes, were tested according to GB/T12967.6-2008 according to examples 1-4 and comparative examples 1-3.

Item	Yield of	Service life of coloring liquid	Flow marks, whitening and mottling
				Example 1	99%	About 3.5 weeks	Is free of
Example 2	99%	About 3 weeks	Is free of
				Example 3	99%	About 3 weeks	Is free of
Example 4	99%	About 3.5 weeks	Is free of
				Comparative example 1	96%	About 2.5 weeks	Slight flow marks and mottling
Comparative example 2	92%	About 2 weeks	Slight flow marks, white spots and mottling
				Comparative example 3	95%	About 2 weeks	Slight flow marks, white spots and mottling

The aluminum alloy workpieces of examples 1-3 have uniform and stable surface color, no obvious surface defects, no flow color and color variation, no white spots, no mottling and no flow mark, and the color difference delta E on each surface of the aluminum alloy workpiece is less than 0.4. The color difference Δ E on each side of the aluminum alloy workpiece of comparative example 1 was 0.3 to 0.6. The color difference Δ E on each side of the aluminum alloy workpiece of comparative example 2 was 0.5 to 0.7. The color difference Δ E on each side of the aluminum alloy workpiece of comparative example 3 was 0.5 to 0.7.

The dyeing additive disclosed by the invention is used for dyeing the aluminum alloy, can improve the dyeing efficiency and uniformity, improve the dyeing effect and the product yield, can be used for treating an aluminum alloy workpiece with a relatively complex appearance structure, solves the problems of color bleeding, heterochrosis and the like in the dyeing process, prolongs the service life of the coloring liquid, and enables the aluminum alloy to have a good appearance effect, good durability and long service life. The aluminum alloy dyeing pretreatment method using the aluminum alloy dyeing pretreatment agent is simple and convenient to operate and easy to control, can remarkably improve dyeing efficiency and uniformity, improves dyeing effect and product yield, is beneficial to obtaining aluminum alloy dyeing workpieces with uniform color and good appearance effect, and is suitable for industrial mass production.

The above-described embodiments are preferred implementations of the present invention, and the present invention may be implemented in other ways without departing from the spirit of the present invention.