阅读说明：本技术 金属材料的表面处理方法 (Surface treatment method for metal material ) 是由 马力 刘鸿章 韩梅 辛阳阳 李晓智 于 2019-09-16 设计创作，主要内容包括：本发明公开了一种金属材料的表面处理方法。该表面处理方法包括：极氧化处理：在所述金属材料的表面形成氧化膜；染色处理：将所述金属材料浸入染料溶液中,以对所述氧化膜进行染色；第一次封孔处理：采用第一封孔液对所述氧化膜进行封孔,其中,所述第一封孔液中含有主剂、碱性物质和阴离子形表面活性剂；第二次封孔处理：采用第二封孔液对所述氧化膜进行封孔处理,所述第一封孔液和所述第二封孔液均为无镍封孔液。(the invention discloses a surface treatment method of a metal material. The surface treatment method comprises the following steps: carrying out polar oxidation treatment: forming an oxide film on the surface of the metal material; dyeing treatment: immersing the metal material in a dye solution to dye the oxide film; and (3) first hole sealing treatment: sealing the oxide film by adopting a first sealing liquid, wherein the first sealing liquid contains a main agent, an alkaline substance and an anionic surface active agent; and (3) second hole sealing treatment: and carrying out hole sealing treatment on the oxide film by adopting a second hole sealing liquid, wherein the first hole sealing liquid and the second hole sealing liquid are both nickel-free hole sealing liquids.)

1. A surface treatment method of a metal material is characterized in that: the method comprises the following steps:

Anodic oxidation treatment: forming an oxide film on the surface of the metal material;

Dyeing treatment: immersing the metal material in a dye solution to dye the oxide film;

And (3) first hole sealing treatment: sealing the oxide film by adopting a first sealing liquid, wherein the first sealing liquid contains a main agent, an alkaline substance and an anionic surface active agent;

and (3) second hole sealing treatment: and carrying out hole sealing treatment on the oxide film by adopting a second hole sealing liquid, wherein the first hole sealing liquid and the second hole sealing liquid are both nickel-free hole sealing liquids.

2. A surface treatment method according to claim 1, characterized in that: the alkaline substance comprises a solution containing ammonium chloride.

3. A surface treatment method according to claim 1, characterized in that: the anionic surface active agent comprises at least one of carboxylate, sulfonate, sulfate and phosphate.

4. a surface treatment method according to claim 1, characterized in that: in the anodic oxidation treatment, the temperature of the electrolyte is: and (2) at 15-25 ℃, the treatment time is as follows: 2500-3500 s, the oxidation voltage is: 10-20V.

5. A surface treatment method according to claim 1, characterized in that: in the dyeing treatment, the temperature of the dye solution is 15-80 ℃, the treatment time is 200-1000 s, and the pH value of the dye solution is 4.0-6.0.

6. a surface treatment method according to claim 1, characterized in that: in the first hole sealing treatment, the temperature of the first hole sealing liquid is 70-90 ℃, the treatment time is 800-1400 s, and the pH of the first hole sealing liquid is 4.0-7.0.

7. A surface treatment method according to claim 1, characterized in that: the temperature of the second hole sealing liquid is 80-100 ℃, the treatment time is 2000-3000 s, and the pH value of the second hole sealing liquid is 5.0-7.0.

8. A surface treatment method according to claim 1, characterized in that: the metal material is pure aluminum, a 5XXX series aluminum alloy, a 6XXX series aluminum alloy, or a 7XXX series aluminum alloy.

9. A surface treatment method according to claim 1, characterized in that: the thickness of the oxide film is 3-25 μm.

10. A surface treatment method according to claim 1, characterized in that: the metal material is accelerated or decelerated into the electrolyte during the anodizing process.

Technical Field

The invention relates to the technical field of surface treatment, in particular to a surface treatment method of a metal material.

Background

Aluminum and aluminum alloys need to be anodized to improve the corrosion resistance of their surfaces. The thickness of the oxide film is usually 10 to 40 μm. However, the anodized film is brittle and has a large amount of microporous structure. The microporous structure may be dyed. However, when the microporous structure is exposed to corrosive substances, pitting corrosion is likely to occur. In order to avoid pitting corrosion, the micropores are usually plugged by a sealing treatment.

The hole sealing treatment mainly utilizes chemical reaction and hydrolysis reaction to fill inorganic matters and/or organic matters into micropores so as to slow down the occurrence of corrosion. In the current industry, the sealing of the oxide film mainly comprises three types of hot sealing, cold sealing and medium temperature sealing. The hole sealing treatment comprises hot hole sealing and cold hole sealing. Wherein, the heat-sealing hole is in pure water near boiling point, and some hydration compounds are generated by the reaction between water and the oxide film layer, so as to seal the micropore.

Cold sealing is a sealing method operated at normal temperature. The method is to deposit corrosion-resistant compounds in the pores, and is also called filling type hole sealing.

The cold sealing method usually adopts one-time sealing. Namely, the dyed metal materials such as aluminum and the like are immersed into the sealant, and are immersed for a set time under the conditions of set temperature, sealant concentration and pH value, so that the sealing operation is completed.

However, the sealing effect of such sealing treatment is not satisfactory, and the durability of the metal material is poor.

Therefore, a new technical solution is needed to solve the above technical problems.

Disclosure of Invention

An object of the present invention is to provide a novel technical solution of a surface treatment method of a metal material.

According to a first aspect of the present invention, there is provided a surface treatment method of a metal material. The surface treatment method comprises the following steps:

Anodic oxidation treatment: forming an oxide film on the surface of the metal material;

Dyeing treatment: immersing the metal material in a dye solution to dye the oxide film;

and (3) first hole sealing treatment: sealing the oxide film by adopting a first sealing liquid, wherein the first sealing liquid contains a main agent, an alkaline substance and an anionic surface active agent;

and (3) second hole sealing treatment: and carrying out hole sealing treatment on the oxide film by adopting a second hole sealing liquid, wherein the first hole sealing liquid and the second hole sealing liquid are both nickel-free hole sealing liquids.

Optionally, the alkaline material comprises a solution comprising ammonium chloride.

Optionally, the anionic surface active agent comprises at least one of a carboxylate, a sulfonate, a sulfate, and a phosphate.

Optionally, in the anodic oxidation treatment, the temperature of the electrolyte is: and (2) at 15-25 ℃, the treatment time is as follows: 2500-3500 s, the oxidation voltage is: 10-20V.

Optionally, in the dyeing treatment, the temperature of the dye solution is 15-80 ℃, the treatment time is 200-1000 s, and the pH value of the dye solution is 4.0-6.0.

Optionally, in the first hole sealing treatment, the temperature of the first hole sealing liquid is 70-90 ℃, the treatment time is 800-1400 s, and the pH of the first hole sealing liquid is 4.0-7.0.

Optionally, the temperature of the second hole sealing liquid is 80-100 ℃, the treatment time is 2000-3000 s, and the pH of the second hole sealing liquid is 5.0-7.0.

Optionally, the metallic material is pure aluminum, a 5XXX series aluminum alloy, a 6XXX series aluminum alloy, or a 7XXX series aluminum alloy.

optionally, the oxide film has a thickness of 3 to 25 μm.

optionally, the metal material is accelerated or decelerated into the electrolyte during the anodizing process.

According to one embodiment of the disclosure, the first hole sealing treatment plays a role in fixing a dye, namely, fixing color, in the first hole sealing treatment, the main agent is an agent capable of filling the holes to play a hole sealing role, the main agent can adopt an agent commonly used in the field, an alkaline substance can be hydrolyzed to generate OH ^- , OH ^- enables the first hole sealing liquid to be easier to react with an oxide film, and therefore the hole sealing effect is achieved, the anionic surfactant can play a wetting role, so that the main agent can be more uniformly dispersed on the oxide film, and the hole sealing effect is better.

In addition, the stability of the reaction product of the first sealing liquid and the oxide film is good, so that the dye is not easy to be separated out from the pores of the oxide film during the second sealing treatment. The second sealing treatment can improve the surface performance of the oxide film.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is a flowchart of a surface treatment method of a metal material according to an embodiment of the present disclosure.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

the following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

According to one embodiment of the present disclosure, a surface treatment method of a metal material is provided. As shown in fig. 1, the surface treatment method includes:

Anodic oxidation treatment: forming an oxide film on the surface of the metal material;

Dyeing treatment: immersing a metal material in a dye solution to dye an oxide film;

And (3) first hole sealing treatment: sealing the oxide film by adopting a first sealing liquid, wherein the first sealing liquid contains a main agent, an alkaline substance and an anionic surface active agent;

And (3) second hole sealing treatment: and sealing the oxide film by using a second sealing liquid, wherein the first sealing liquid and the second sealing liquid are both nickel-free sealing liquids.

The purpose of the anodic oxidation treatment is to form an oxide film on the surface of the metal material. The anodic oxidation treatment is carried out in an electrolytic solution. For example, the electrolyte is at least one of a sulfuric acid solution, a phosphoric acid solution, and an oxalic acid solution. For example, the metal material is suspended into the electrolyte by means of a hanger. At a set voltage, the surface of the metal material as an anode is oxidized to form an oxide film.

For example, the metal material is pure aluminum, a 5XXX series aluminum alloy, a 6XXX series aluminum alloy, or a 7XXX series aluminum alloy. The oxide film formed on the surface of the material has high speed and stable property.

for example, in the anodic oxidation treatment, the temperature of the electrolyte is: and (2) at 15-25 ℃, the treatment time is as follows: 2500-3500 s, the oxidation voltage is: 10-20V. Under the above process conditions, the oxide film is uniform and complete. Micro-scale, nano-scale and micro-nano-scale pores can be formed on the surface and inside of the oxide film. The pores can adsorb dye, so that the dyeing effect of the metal material is more excellent.

for example, the thickness of the oxide film is 3 to 25 μm. Within this range, the dyeing effect of the oxide film is good, and the structural strength of the metal material is high.

For example, in the dyeing treatment, the temperature of the dye solution is 15-80 ℃, the treatment time is 200-1000 s, and the pH value of the dye solution is 4.0-6.0. Under the above process conditions, the dye can sufficiently enter the pores of the oxide film, thereby coloring the oxide film.

the first hole sealing treatment has the effect of fixing dye, namely the color fixing effect, in the first hole sealing treatment, the main agent is a medicament capable of filling holes to play a hole sealing effect, the main agent can adopt a medicament commonly used in the field, alkaline substances can be hydrolyzed to generate OH ^- , OH ^- enables the first hole sealing liquid to be easier to react with an oxide film to generate AlO ₂ ^- , and therefore the hole sealing effect is achieved.

In addition, the stability of the reaction product of the first sealing liquid and the oxide film is good, so that the dye is not easy to be separated out from the pores of the oxide film during the second sealing treatment. The second hole sealing treatment can improve the surface corrosion resistance of the oxide film.

Furthermore, the method is simple. The first hole sealing liquid and the second hole sealing liquid are both nickel-free hole sealing liquids, so that the metal material after surface treatment does not contain nickel, and the harm to the health of a human body is small.

in one example, the basic substance comprises a solution containing ammonium chloride, the solution containing ammonium chloride comprises ammonia water, a mixed solution of ammonia water and other substances, and the like, the ammonium chloride can ionize NH ₃ ⁺ and OH ^- , and the ammonium chloride can form ionization balance with ammonia monohydrate (namely NH ₃. H ₂ O), so that the concentration of OH ^- in the first sealing liquid is stable.

in addition, the solution containing ammonium chloride has low alkalinity, so that the solution can not react with the oxide film, and the stability of the oxide film is ensured.

Of course, the alkaline substance can also be NaOH, KOH, Na ₂ CO ₃, NaHCO ₃, alkaline organic substance, and the like.

in one example, the anionic surface active agent comprises at least one of a carboxylate, a sulfonate, a sulfate, and a phosphate. The above surfactants can all play a role in wetting.

Preferably, the anionic surfactant is sodium alkyl sulfonate. The material has good wetting effect. The surface properties of the oxide film are good.

In one example, in the first hole sealing treatment, the temperature of the first hole sealing liquid is 70-90 ℃, the treatment time is 800-1400 s, and the pH of the first hole sealing liquid is 4.0-7.0. Under the process condition, the color fixing effect of the first hole sealing treatment is good.

In one example, in the first hole sealing treatment, the temperature of the second hole sealing liquid is 80-100 ℃, the treatment time is 2000-3000 s, and the pH of the second hole sealing liquid is 5.0-7.0. Under the process conditions, the surface properties of the oxide film are excellent.

In one example, the metal material is accelerated or decelerated into the electrolyte as the anodizing process is performed. The metal material is put into the electrolyte in an acceleration or deceleration mode, and the thickness of the oxide film is different because different parts of the metal material stay in the electrolyte for different time. For example, the longer the residence time, the greater the thickness of the oxide film; conversely, the shorter the residence time, the smaller the thickness of the oxide film. By controlling the acceleration of the metal material into the electrolyte, the thickness of the oxide film is changed in a gradient manner, rather than forming an oxide film with a uniform thickness.

When the dyeing treatment is performed, the dye enters pores formed by the oxide film, thereby coloring the oxide film. When the dyeing is performed with the oxide film having a different thickness, the color of the surface of the metal material is different.

For example, the greater the thickness, the greater the depth of the pores, the more dye can be accommodated, and the darker the color of the area dyed; conversely, the smaller the thickness, the smaller the depth of the pores, the less dye can be accommodated, and the lighter the color of the area dyed. Since the thickness of the oxide film changes in a gradient manner, the color of the metal material changes in a gradient manner after dyeing, i.e., a gradient color is formed.

The thickness of the oxide film can be controlled by controlling the length of the anodic oxidation time.

In one example, a pretreatment is further included before the anodic oxidation. For example, the pretreatment includes washing, degreasing, neutralization, chemical polishing, water washing, and the like. Wherein, the purpose of washing is to remove impurities such as dust, mud and the like on the surface of the metal material. The degreasing aims to remove grease on the surface of the metal material, prevent the grease from covering the surface of the metal material and slow down the anodic oxidation speed. The purpose of chemical polishing is to smooth and uniform the surface of the metal material. The water washing can remove the residual chemical agent and the generated impurities.

In one example, post-treatment is included after the sealing treatment is performed. The post-treatment comprises the steps of ash removal, washing, drying and the like of the metal material.

< example >

In this embodiment, the metal material is a 6063 series aluminum alloy material. The electrolyte is sulfuric acid solution.

s1, pretreating the surface of the 6063 aluminum alloy material;

S2, immersing the aluminum alloy into electrolyte to carry out anodic oxidation treatment; the concentration of the sulfuric acid solution is 210g/L, and the technological parameters of the anodic oxidation treatment are as follows: the temperature of the sulfuric acid solution is 19 ℃, the treatment time is 2800s, and the oxidation voltage is 15V;

S3, immersing the aluminum alloy material into a dye solution for dyeing; the color of the dye is wood black; the dyeing process comprises the following process parameters: the temperature of the dye solution is 20 ℃, the treatment time is 240s, and the pH value is 5.0;

s4, carrying out first hole sealing treatment on the dyed aluminum alloy material; wherein the first hole sealing liquid is SH-2 produced by Laine of Switzerland; the technological parameters of the first hole sealing treatment are as follows: the concentration of the first hole sealing liquid is 5ml/L, the temperature of the first hole sealing liquid is 80 ℃, and the treatment time is as follows: 1200s, the pH value of the first hole sealing liquid is 5.5;

S5, carrying out second hole sealing treatment on the aluminum alloy material; wherein the second hole sealing liquid is ES-1 produced by Laine of Switzerland; the technological parameters of the second hole sealing are as follows: the concentration of the second hole sealing liquid is 12ml/L, the temperature of the second hole sealing liquid is 95 ℃, the treatment time is 2400s, and the pH value of the second hole sealing liquid is 6.0;

S6, post-processing; and (3) carrying out post-treatment steps such as ash removal, hot water washing, drying and the like on the aluminum alloy material to finally obtain a colored aluminum alloy product.

In order to test the sealing quality, the aluminum alloy product was tested.

First, sample weight loss test

1) Preparation of a test solution:

Weighing 20.0 +/-0.5 g of chromic anhydride;

measuring 35.0 +/-0.5 ml of phosphoric acid with the mass concentration of 85 percent;

Diluting the two substances to 1000ml with pure water;

2) Measurement: weighing a sample with the area A (unit: d square meter) to the weight of 0.001g, and recording as W1; placing the sample in a test solution at 38 + -0.1 deg.C, and standing at constant temperature for 15 + -0.1 min;

After the tested sample is removed from the test solution, the sample is washed with pure water, then dried by hot air, and the weight of the sample is weighed again to be accurate to 0.001g, which is recorded as W2;

the calculation method comprises the following steps: x (mg/square meter) (W1-W2)/a. Evaluation criteria: x is less than 30mg/d square meter, namely X is less than 30mg/d square meter.

Table 1 shows the results of weight loss tests performed on 3 samples taken daily for five consecutive days.

as can be seen from the table, the weight loss per square decimeter for all samples is much less than 30 mg. The aluminum alloy product obtained by the nickel-free treatment method after the surface of the sample is anodized in the embodiment of the invention has excellent hole sealing quality.

Second, testing of nickel release from aluminum alloy products

preparation of a test solution:

reagent A: weighing 1.0g of dimethylglyoxime reagent and placing the dimethylglyoxime reagent in a 100ml beaker; dissolving with anhydrous ethanol to constant volume of 100 ml;

And (3) reagent B: pouring 35.7ml of 10% ammonia water into a volumetric flask, and adding pure water to a constant volume of 100 ml;

Mixing reagents: and uniformly mixing the reagent A and the reagent B according to the volume ratio of 1: 1.

A detection step:

1) Dropping 2-3 drops of the mixed reagent on a cotton swab by using a rubber head dropper;

2) Wiping the surface of the aluminum alloy product by a cotton swab under a set pressure for 10 times;

3) Observing whether the mixed reagent on the surface of the aluminum alloy product and the cotton swab turns pink or not; if the mixed reagent on the surface and the cotton swab turns pink, nickel on the surface of the sample is dissolved out; if the mixed reagent on the surface of the product and the cotton swab does not turn pink, no nickel is dissolved from the surface of the sample.

6 samples were taken from the same batch for testing. 2 samples are taken from the upper part, the middle part and the lower part of the hanger respectively. Samples were withdrawn for 10 consecutive days for testing.

The surface of all samples and the corresponding cotton swab did not turn pink upon testing. As can be seen from the results of the nickel release test, the aluminum alloy product obtained by the surface treatment method of the embodiment of the invention reaches the nickel-free standard.

And thirdly, testing reliability.

The reliability test was performed using the samples prepared in the above examples, 12 samples were taken for each test item, the samples were rectangular, and the surface area of the samples was 0.3068dm ².

as can be seen from the reliability measurement results, the samples obtained by the surface treatment method of the invention are all qualified after being tested by all the test items, and the samples treated by the surface treatment method have excellent corrosion resistance.

although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.