阅读说明：本技术 稳定型铝合金电解着色工艺 (Stable aluminum alloy electrolytic coloring process ) 是由 宋志健 喻诚 于 2020-12-04 设计创作，主要内容包括：本发明涉及稳定型铝合金电解着色工艺,涉及铝型材生产加工技术领域。稳定型铝合金电解着色工艺,包括(a)表面预处理：对铝合金的表面进行净化处理,包括脱脂、碱蚀和中和出光；(b)电解活化处理；(c)阳极氧化处理；(d)电解着色；(e)封闭和(f)干燥等步骤。该发明的有益效果：可以得到赭红色的膜,且该赭红色膜的耐腐蚀性能优于同条件下单镍盐的青铜色膜,着色液稳定、色泽均匀,再现性良好。(The invention relates to a stable aluminum alloy electrolytic coloring process, and relates to the technical field of aluminum profile production and processing. The stable aluminum alloy electrolytic coloring process comprises the following steps of (a) surface pretreatment: purifying the surface of the aluminum alloy, including degreasing, alkaline etching and neutralization brightening; (b) electrolytic activation treatment; (c) carrying out anodic oxidation treatment; (d) electrolytic coloring; (e) sealing and (f) drying. The invention has the beneficial effects that: an ochre film can be obtained, the corrosion resistance of the ochre film is superior to that of a bronze film made of mono-nickel salt under the same condition, and the coloring liquid is stable, uniform in color and good in reproducibility.)

1. The stable aluminum alloy electrolytic coloring process comprises the following steps:

(a) surface pretreatment: purifying the surface of the aluminum alloy, including degreasing, alkaline etching and neutralization brightening;

(b) electrolytic activation treatment: cleaning the pretreated aluminum alloy, and then carrying out electrolytic activation in an activating solution, wherein the formula of the activating solution comprises: 4-8g/L concentrated sulfuric acid, 0.1-0.5g/L chromic acid, 5-8g/L corrosion inhibitor and water, wherein the activation temperature is 30-50 ℃, the electrolysis time is 10-40s, and the current density is 1-3A/dm 2;

(c) anodic oxidation treatment: putting the aluminum alloy subjected to electrolytic activation treatment into an anodic oxidation tank, and electrifying for 10-15min at a current density of 1-3A/dm²Carrying out electrolytic oxidation treatment at the temperature of 15-30 ℃;

the formula of the anodic oxidation bath solution is as follows: 95-98% concentrated sulfuric acid 150-200g/L and sulfosalicylic acid 15-20 g/L;

(d) electrolytic coloring: placing the anodized aluminum alloy in an electrolyte for alternating current electrolytic coloring, wherein the alternating current voltage is 10-20V, the coloring temperature is 20-30 ℃, and the coloring time is 1-4 min;

the ratio of the coloring liquid is as follows: 20-35g/L of nickel sulfate, 20-30g/L of boric acid, 10-15g/L of ammonium sulfate, 15-20g/L of sulfuric acid, 5-15g/L of copper chloride, 1-5g/L of a coloring stabilizer and 3-6 of PH;

(e) and (3) sealing: sealing the colored aluminum alloy by using nickel salt;

(f) and (3) drying: and drying the section in a far infrared room.

2. The electrolytic coloring process for stable aluminum alloys according to claim 1, wherein: the solution components adopted for degreasing in the step (a) comprise 5-15g/L of sodium hydroxide, 30-50g/L of Na3PO4.12H2O and a detergent, the reaction temperature is 45-65 ℃, the reaction time is 1-5min, and the solution components are cleaned by hot water after treatment.

3. The electrolytic coloring process for stable aluminum alloys according to claim 1, wherein: the component content of the solution adopted by the alkaline etching in the step (a) comprises: 15-25g/L of sodium hydroxide, 25-35g/L of alkaline etching agent and 1-2g/L of sodium dodecyl sulfate, the reaction temperature is 55-65 ℃, the reaction time is 1-5min, and the aluminum profile is immediately flushed by flowing water after alkaline etching.

4. The electrolytic coloring process for stable aluminum alloys according to claim 1, wherein: the solution components adopted for neutralizing light emission in the step (a) comprise: 60-100g/L of nitric acid, and the reaction time is 30-60 s.

5. The electrolytic coloring process for stable aluminum alloys according to claim 1, wherein: the coloring stabilizer in the step (d) is prepared by compounding hydroxycarboxylic acid and inorganic oxysalt.

6. The electrolytic coloring process for stable aluminum alloys according to claim 1, wherein: the drying temperature in the step (f) is 50-60 ℃.

Technical Field

The invention relates to a stable aluminum alloy electrolytic coloring process, and belongs to the technical field of aluminum profile production and processing.

Background

The aluminum alloy has low density and high strength ratio. Is one of the most widely used nonferrous metal structural materials in industry, and has excellent electrical conductivity, thermal conductivity and corrosion resistance. Meanwhile, because the aluminum alloy has low density, low price, low toxicity and mature forming process, compared with stainless steel and titanium alloy, the aluminum alloy has very wide development space in the fields of medical instruments, foods, household devices and the like.

Anodic oxidation electrolytic coloring of aluminum alloys is one of the most widely applicable treatment methods in surface treatment of aluminum alloys. An anodic oxidation method is utilized to form a compact and thick oxide film layer on the surface of the aluminum alloy, thereby obviously improving the corrosion resistance of the aluminum alloy and enhancing the hardness, wear resistance and decorative performance of the aluminum alloy. The electrolytic coloring method for aluminum alloys is a method in which an oxide film is formed in a general electrolytic solution, and then electrolysis is performed again in a metal salt electrolytic solution to deposit cations of a metal salt on a vacuum bottom layer of the oxide film to color the film. In the prior art, metal copper is electrolytically deposited in an aluminum profile oxide film to obtain a red oxide film, so that the surface of a red aluminum alloy is obtained, but the phenomenon of fading is easy to occur in the production process due to the special production process of electrolytic copper coloring, so that the production yield is low, and the weather resistance is poor.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a stable aluminum alloy electrolytic coloring process, which has the following specific technical scheme:

the stable aluminum alloy electrolytic coloring process comprises the following steps:

(a) surface pretreatment: purifying the surface of the aluminum alloy, including degreasing, alkaline etching and neutralization brightening;

(b) electrolytic activation treatment: cleaning the pretreated aluminum alloy, and then carrying out electrolytic activation in an activating solution, wherein the formula of the activating solution comprises: 4-8g/L concentrated sulfuric acid, 0.1-0.5g/L chromic acid, 5-8g/L corrosion inhibitor and water, wherein the activation temperature is 30-50 ℃, the electrolysis time is 10-40s, and the current density is 1-3A/dm 2;

(c) anodic oxidation treatment: putting the aluminum alloy subjected to electrolytic activation treatment into an anodic oxidation tank, and electrifying for 10-15min with the current density of 1-3A/dm²Carrying out electrolytic oxidation treatment at the temperature of 15-30 ℃;

the formula of the anodic oxidation bath solution is as follows: 95-98% concentrated sulfuric acid 150-200g/L and sulfosalicylic acid 15-20 g/L;

(d) electrolytic coloring: placing the anodized aluminum alloy in an electrolyte for alternating current electrolytic coloring, wherein the alternating current voltage is 10-20V, the coloring temperature is 20-30 ℃, and the coloring time is 2-10 min;

the ratio of the coloring liquid is as follows: 20-35g/L of nickel sulfate, 20-30g/L of boric acid, 10-15g/L of ammonium sulfate, 15-20g/L of sulfuric acid, 5-15g/L of copper chloride and 1-5g/L of a coloring stabilizer;

(e) and (3) sealing: sealing the colored aluminum alloy by using nickel salt;

(f) and (3) drying: and drying the section in a far infrared room.

The stable aluminum alloy electrolytic coloring process adopts the steps that the surface of the aluminum alloy is pretreated, the quality of the pretreatment directly influences the electrolytic coloring quality, the subsequent electrolytic coloring efficiency can be improved, dirt such as lubricating oil and antirust oil on the surface of the aluminum alloy can be removed by degreasing, and the quality of the aluminum alloy is improved; the surface smoothness of the aluminum alloy can be improved by the alkali etching, so that the electrolytic coloring is brighter in color and better in decorative property; the neutralization light-emitting can remove the ash on the surface of the aluminum product and ensure the uniformity and transparency of the oxide film; the anodic oxidation treatment can obtain a fresh porous oxide film layer on the surface of the aluminum product; when in electrolytic coloring, a small amount of CuCl is added into the nickelous salt₂An ochre film can be obtained, and the corrosion resistance of the ochre film is superior to that of a bronze film of single nickel salt under the same condition.

Further, degreasing in the step (a) is to remove oil stains on the surface of the aluminum alloy section, uniformly corrode the surface of the aluminum section and eliminate the uneven condition of the surface of the aluminum section, and the adopted solution components comprise 5-15g/L of sodium hydroxide, 30-50g/L of Na3PO4.12H2O and a detergent, the reaction temperature is 45-65 ℃, the reaction time is 1-5min, and the aluminum section is cleaned by hot water after treatment.

Further, the alkaline etching in the step (a) is to remove dirt on the surface of the aluminum profile by using an alkaline cleaning agent, and the adopted solution comprises the following components: 15-25g/L of sodium hydroxide, 25-35g/L of alkaline etching agent and 1-2g/L of sodium dodecyl sulfate, the reaction temperature is 55-65 ℃, the reaction time is 1-5min, and the aluminum profile is immediately flushed by flowing water after alkaline etching.

Further, the solution components for neutralizing light in the step (a) comprise: 60-100g/L of nitric acid, and the reaction time is 30-60 s.

Further, the coloring stabilizer in the step (d) is prepared by compounding hydroxycarboxylic acid and inorganic oxysalt.

Further, the drying temperature in the step (f) is 50-60 ℃.

The invention has the beneficial effects that:

the stable aluminum alloy electrolytic coloring process adopts the steps that the surface of the aluminum alloy is pretreated, the quality of the pretreatment directly influences the electrolytic coloring quality, the subsequent electrolytic coloring efficiency can be improved, dirt such as lubricating oil and antirust oil on the surface of the aluminum alloy can be removed by degreasing, and the quality of the aluminum alloy is improved; the surface smoothness of the aluminum alloy can be improved by the alkali etching, so that the electrolytic coloring is brighter in color and better in decorative property; the neutralization light-emitting can remove the ash on the surface of the aluminum product and ensure the uniformity and transparency of the oxide film; the anodic oxidation treatment can obtain a fresh porous oxide film layer on the surface of the aluminum product; when in electrolytic coloring, a small amount of CuCl is added into the nickelous salt₂An ochre film can be obtained, the corrosion resistance of the ochre film is superior to that of a bronze film made of mono-nickel salt under the same condition, and the coloring liquid is stable, uniform in color and good in reproducibility.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example one

The stable aluminum alloy electrolytic coloring process of the embodiment comprises the following steps:

(a) surface pretreatment: purifying the surface of the aluminum alloy, including degreasing, alkaline etching and neutralization brightening;

wherein, the solution components adopted for degreasing comprise 5g/L of sodium hydroxide, 35g/L of Na3PO4.12H2O and detergent, the reaction temperature is 50 ℃, the reaction time is 1min, and the solution is cleaned by hot water after treatment;

the alkaline etching adopts solution components with contents as follows: 15g/L of sodium hydroxide, 25g/L of alkaline etching agent and 1g/L of sodium dodecyl sulfate, the reaction temperature is 55 ℃, the reaction time is 1min, and the aluminum profile is immediately flushed by flowing water after alkaline etching;

the solution components adopted for neutralizing and brightening comprise 60g/L nitric acid, and the reaction time is 30 s;

(b) electrolytic activation treatment: cleaning the pretreated aluminum alloy, and then carrying out electrolytic activation in an activating solution, wherein the formula of the activating solution comprises: 4g/L of concentrated sulfuric acid, 0.1g/L of chromic acid, 5g/L of corrosion inhibitor and water, the activation temperature is 35 ℃, the electrolysis time is 15s, and the current density is 1A/dm²；

(c) Anodic oxidation treatment: putting the aluminum alloy subjected to electrolytic activation treatment into an anodic oxidation tank, and electrifying for 10min with a current density of 1A/dm²Carrying out electrolytic oxidation treatment at the temperature of 15 ℃;

the formula of the anodic oxidation bath solution is as follows: 150g/L of 95-98% concentrated sulfuric acid and 15g/L of sulfosalicylic acid;

(d) electrolytic coloring: placing the anodized aluminum alloy in an electrolyte for alternating current electrolytic coloring, wherein the alternating current voltage is 10V, the coloring temperature is 20 ℃, and the coloring time is 1 min;

the ratio of the coloring liquid is as follows: 20g/L of nickel sulfate, 20g/L of boric acid, 10g/L of ammonium sulfate, 15g/L of sulfuric acid, 5g/L of copper chloride, 1g/L of coloring stabilizer and 3 of PH, wherein the coloring stabilizer is prepared by compounding hydroxycarboxylic acid and inorganic oxysalt;

(e) and (3) sealing: sealing the colored aluminum alloy by using nickel salt;

(f) and (3) drying: drying the section in a far infrared room at 50 ℃.

Example 2

The stable aluminum alloy electrolytic coloring process of the embodiment comprises the following steps:

(a) surface pretreatment: purifying the surface of the aluminum alloy, including degreasing, alkaline etching and neutralization brightening;

wherein, the solution components adopted for degreasing comprise 10g/L of sodium hydroxide, 35g/L of Na3PO4.12H2O and detergent, the reaction temperature is 50 ℃, the reaction time is 2min, and the solution is cleaned by hot water after treatment;

the alkaline etching adopts solution components with contents as follows: 25g/L of sodium hydroxide, 30g/L of alkaline etching agent and 2g/L of sodium dodecyl sulfate, the reaction temperature is 60 ℃, the reaction time is 3min, and the aluminum profile is immediately flushed by flowing water after alkaline etching;

the solution components adopted for neutralizing and brightening comprise 80g/L nitric acid, and the reaction time is 50 s;

(b) electrolytic activation treatment: cleaning the pretreated aluminum alloy, and then carrying out electrolytic activation in an activating solution, wherein the formula of the activating solution comprises: concentrated sulfuric acid 6g/L, chromic acid 0.3g/L, corrosion inhibitor 6g/L and water, the activation temperature is 40 ℃, the electrolysis time is 30s, and the current density is 2A/dm²；

(c) Anodic oxidation treatment: putting the aluminum alloy subjected to electrolytic activation treatment into an anodic oxidation tank, and electrifying for 15min with the current density of 2A/dm²Carrying out electrolytic oxidation treatment at the temperature of 20 ℃;

the formula of the anodic oxidation bath solution is as follows: 180g/L of 95-98% concentrated sulfuric acid and 18g/L of sulfosalicylic acid;

(d) electrolytic coloring: placing the anodized aluminum alloy in an electrolyte for alternating current electrolytic coloring, wherein the alternating current voltage is 15V, the coloring temperature is 25 ℃, and the coloring time is 2 min;

the ratio of the coloring liquid is as follows: 25g/L of nickel sulfate, 25g/L of boric acid, 15g/L of ammonium sulfate, 15g/L of sulfuric acid, 10g/L of copper chloride, 3g/L of a coloring stabilizer and 4 of PH, wherein the coloring stabilizer is prepared by compounding hydroxycarboxylic acid and inorganic oxysalt;

(e) and (3) sealing: sealing the colored aluminum alloy by using nickel salt;

(f) and (3) drying: drying the section in a far infrared room at 55 ℃.

Example 3

The stable aluminum alloy electrolytic coloring process of the embodiment comprises the following steps:

(a) surface pretreatment: purifying the surface of the aluminum alloy, including degreasing, alkaline etching and neutralization brightening;

wherein, the solution components adopted for degreasing comprise 15g/L of sodium hydroxide, 45g/L of Na3PO4.12H2O and a detergent, the reaction temperature is 60 ℃, the reaction time is 4min, and the solution components are cleaned by hot water after treatment;

the alkaline etching adopts solution components with contents as follows: 25g/L of sodium hydroxide, 30g/L of alkaline etching agent and 2g/L of sodium dodecyl sulfate, the reaction temperature is 60 ℃, the reaction time is 3min, and the aluminum profile is immediately flushed by flowing water after alkaline etching;

the solution components adopted for neutralizing and brightening comprise 80g/L nitric acid, and the reaction time is 50 s;

(b) electrolytic activation treatment: cleaning the pretreated aluminum alloy, and then carrying out electrolytic activation in an activating solution, wherein the formula of the activating solution comprises: 68g/L of concentrated sulfuric acid, 0.5g/L of chromic acid, 8g/L of corrosion inhibitor and water, wherein the activation temperature is 40 ℃, the electrolysis time is 30s, and the current density is 3A/dm 2;

(c) anodic oxidation treatment: putting the aluminum alloy subjected to electrolytic activation treatment into an anodic oxidation tank, and electrifying for 15min with the current density of 3A/dm²Carrying out electrolytic oxidation treatment at the temperature of 30 ℃;

the formula of the anodic oxidation bath solution is as follows: 180g/L of 95-98% concentrated sulfuric acid and 20g/L of sulfosalicylic acid;

(d) electrolytic coloring: placing the anodized aluminum alloy in an electrolyte for alternating current electrolytic coloring, wherein the alternating current voltage is 20V, the coloring temperature is 25 ℃, and the coloring time is 3 min;

the ratio of the coloring liquid is as follows: 30g/L of nickel sulfate, 25g/L of boric acid, 15g/L of ammonium sulfate, 16g/L of sulfuric acid, 15g/L of copper chloride and 5g/L of a coloring stabilizer, wherein the pH is 5, and the coloring stabilizer is prepared by compounding hydroxycarboxylic acid and inorganic oxysalt;

(e) and (3) sealing: sealing the colored aluminum alloy by using nickel salt;

(f) and (3) drying: drying the section in a far infrared room at 60 ℃.

The aluminum alloy sections obtained in the above examples 1, 2 and 3 were subjected to coloring tests according to the amount of copper chloride added and the length of coloring time, and the results obtained are shown in the following table:

as can be seen from the above table, with CuCl in the coloring liquid₂The content is increased, the color of the film is gradually deepened, and CuCl is not added₂The colored film of the mono-nickel salt is not ochre but bronze, the mono-copper salt without adding NiSO4 is not colored at all, and the CuCl is simultaneously used₂When the content is 5g/L, the surface of the aluminum alloy can be colored, the color of the film layer is not bronze, but ochre, and the corrosion resistance of the ochre film is superior to that of the bronze film of the nickelous salt under the same condition.

Comparative example

Adding aluminum alloy into the aluminum alloy without adding CuCl₂The single nickel salt coloring solution is colored, and other conditions are the same as the conditions of the invention;

respectively putting the colored samples obtained in the above examples 1, 2 and 3 and the comparative example into 50g/L NaCl solution for soaking for 90 hours, and carrying out salt corrosion resistance experiments; soaking in hydrochloric acid solution with pH of 1 for 30h to perform acid etching resistance experiment; and soaking in NaOH solution with pH of 10 for 30h for alkali corrosion resistance experiment, and measuring weight loss data by using an analytical balance, wherein the weight loss data are shown in the following table:

as can be seen from the above table, the salt corrosion resistance, the acid corrosion resistance, and the alkali corrosion resistance of each of the samples of examples 1, 2, and 3 are superior to those of the sample of comparative example, and the resulting film layer is more stable.

It is noted that, in this document, relational terms such as first and second, and the like, if any, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.