CN114351209A - Normal-temperature low-voltage hard anodizing process method for aluminum alloy - Google Patents
Normal-temperature low-voltage hard anodizing process method for aluminum alloy Download PDFInfo
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- CN114351209A CN114351209A CN202111507102.9A CN202111507102A CN114351209A CN 114351209 A CN114351209 A CN 114351209A CN 202111507102 A CN202111507102 A CN 202111507102A CN 114351209 A CN114351209 A CN 114351209A
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- 238000000034 method Methods 0.000 title claims abstract description 53
- 229910000838 Al alloy Inorganic materials 0.000 title claims abstract description 29
- 230000008569 process Effects 0.000 title claims abstract description 29
- 238000007743 anodising Methods 0.000 title claims description 22
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 claims abstract description 66
- OFOBLEOULBTSOW-UHFFFAOYSA-N Malonic acid Chemical compound OC(=O)CC(O)=O OFOBLEOULBTSOW-UHFFFAOYSA-N 0.000 claims abstract description 44
- JVTAAEKCZFNVCJ-UHFFFAOYSA-N lactic acid Chemical compound CC(O)C(O)=O JVTAAEKCZFNVCJ-UHFFFAOYSA-N 0.000 claims abstract description 44
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims abstract description 36
- 239000004310 lactic acid Substances 0.000 claims abstract description 22
- 235000014655 lactic acid Nutrition 0.000 claims abstract description 22
- 235000006408 oxalic acid Nutrition 0.000 claims abstract description 22
- 230000003647 oxidation Effects 0.000 claims abstract description 18
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 18
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 claims abstract description 5
- 125000002887 hydroxy group Chemical group [H]O* 0.000 claims abstract description 5
- 239000000243 solution Substances 0.000 claims description 32
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 11
- 238000005406 washing Methods 0.000 claims description 10
- 239000000463 material Substances 0.000 claims description 7
- 230000001590 oxidative effect Effects 0.000 claims description 7
- 238000001035 drying Methods 0.000 claims description 4
- 238000007789 sealing Methods 0.000 claims description 4
- 238000002791 soaking Methods 0.000 claims description 4
- 239000011259 mixed solution Substances 0.000 claims description 2
- 239000000956 alloy Substances 0.000 claims 1
- 238000004140 cleaning Methods 0.000 claims 1
- 239000004519 grease Substances 0.000 claims 1
- 239000007788 liquid Substances 0.000 claims 1
- 238000004090 dissolution Methods 0.000 abstract description 6
- 238000001816 cooling Methods 0.000 abstract description 5
- 239000008399 tap water Substances 0.000 description 8
- 235000020679 tap water Nutrition 0.000 description 8
- 238000005265 energy consumption Methods 0.000 description 4
- 238000005057 refrigeration Methods 0.000 description 4
- 238000005238 degreasing Methods 0.000 description 3
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- 239000010407 anodic oxide Substances 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 238000002679 ablation Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical group [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 description 1
- 238000002048 anodisation reaction Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000007123 defense Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 239000001488 sodium phosphate Substances 0.000 description 1
- 229910000162 sodium phosphate Inorganic materials 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- RYFMWSXOAZQYPI-UHFFFAOYSA-K trisodium phosphate Chemical compound [Na+].[Na+].[Na+].[O-]P([O-])([O-])=O RYFMWSXOAZQYPI-UHFFFAOYSA-K 0.000 description 1
Classifications
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- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
- C25D11/02—Anodisation
- C25D11/04—Anodisation of aluminium or alloys based thereon
- C25D11/06—Anodisation of aluminium or alloys based thereon characterised by the electrolytes used
- C25D11/08—Anodisation of aluminium or alloys based thereon characterised by the electrolytes used containing inorganic acids
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
- C25D11/02—Anodisation
- C25D11/04—Anodisation of aluminium or alloys based thereon
- C25D11/06—Anodisation of aluminium or alloys based thereon characterised by the electrolytes used
- C25D11/10—Anodisation of aluminium or alloys based thereon characterised by the electrolytes used containing organic acids
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Chemical Treatment Of Metals (AREA)
Abstract
The invention relates to a normal-temperature low-voltage hard anodic oxidation process method for aluminum alloy, which aims to improve the working temperature of hard anodic oxidation and reduce the current density and the final voltage, thereby eliminating equipment such as forced cooling, alternating current and direct current superposition or pulse current and the like, realizing hard anodic oxidation treatment on aluminum alloy parts under the conditions of normal temperature and low voltage (20-24V) direct current, and finally achieving the purposes of saving energy, protecting environment, reducing the equipment cost and simplifying the working conditions. The method is that oxalic acid is added into sulfuric acid solution, lactic acid or malonic acid is added, carboxyl and hydroxyl in oxalic acid, lactic acid or malonic acid are utilized to increase the growth speed of the oxide film, which is larger than the dissolution speed of the film, and the oxide film with high hardness and thick film layer is obtained.
Description
Technical Field
The invention belongs to the field of aluminum alloy surface treatment, and relates to a normal-temperature low-voltage hard anodizing process method for aluminum alloy.
Background
The hard anode oxidation of the aluminum alloy can produce a hard and porous thick oxide film on the surface of an aluminum alloy product, and the thickness range is 20-250 mu m. Due to the excellent characteristics of the hard anodic oxide film, the hard anodic oxide film is widely applied to aluminum parts with high requirements on heat resistance, wear resistance and insulativity. The hard anodizing process commonly applied in the national defense industry is a traditional low-temperature sulfuric acid hard anodizing process, in order to ensure that the hardness and the film thickness of a film layer meet the requirements, the working temperature must be kept at-5 ℃, heat released in the film forming process needs to be discharged by strong refrigeration equipment, air stirring and other methods, and otherwise the problems of film layer looseness, part edge ablation and the like easily occur; in addition, the current density and the termination voltage of the traditional low-temperature process are high (mostly 60V-120V), and alternating current and direct current superposition or pulse current is needed. Therefore, the traditional low-temperature sulfuric acid hard anodizing process has the disadvantages of high energy consumption, high equipment investment and complex working conditions, and further causes higher production cost.
Disclosure of Invention
The invention provides a process method for hard anodizing of aluminum alloy, which can be carried out under the conditions of normal temperature and low voltage, namely a process method for hard anodizing of aluminum alloy at normal temperature and low voltage. In order to improve the hard anodizing working temperature and reduce the current density and the final voltage, equipment such as forced cooling, alternating current and direct current superposition or pulse current and the like is omitted, the hard anodizing treatment on the aluminum alloy part is realized under the direct current conditions of normal temperature and low voltage (20-24V), and the aims of saving energy, protecting environment, reducing the equipment cost and simplifying the working conditions are finally fulfilled.
The purpose of the invention is realized by the following technical scheme:
a normal-temperature low-voltage hard anodic oxidation process method for aluminum alloy is characterized in that the oxidation adopts the following solutions: the mixed solution of sulfuric acid solution, oxalic acid, lactic acid or malonic acid has carboxyl and hydroxyl groups in oxalic acid, lactic acid or malonic acid to raise the growth rate of the oxide film to be higher than the dissolving rate of the oxide film.
Further, in the oxidizing solution, the oxidizing solution is heated at a current of 1 to 2A/dm2And (5) electrifying to form a film.
A normal-temperature low-voltage hard anodizing process method for aluminum alloy is characterized in that an oxidizing solution for hard anodizing the aluminum alloy comprises the following components: sulfuric acid solution, oxalic acid, lactic acid or malonic acid; 200-300 g/L of sulfuric acid solution, 50-75 g/L of oxalic acid and 50-75 g/L of lactic acid or malonic acid.
A normal-temperature low-voltage hard anodizing process method for aluminum alloy is characterized in that an oxidizing solution for hard anodizing the aluminum alloy comprises the following components: sulfuric acid solution, oxalic acid, lactic acid or malonic acid; 200-300 g/L of sulfuric acid solution, 50-75 g/L of oxalic acid and 50-75 g/L of lactic acid or malonic acid;
the solution temperature is 16-22 ℃, and the soaking time is 60-70 min;
the material electrifying voltage is 20-24V;
the current density of the material is controlled from 0.1 A.dm within the first 20 minutes-2Gradually increased to 0.5 A.dm-2；
Gradually increasing to 1-2 A.dm within 20-25 minutes-2The oxidation is kept complete.
The principle of the invention is as follows:
the invention relates to a process method for hard anodizing of aluminum alloy, which can be carried out under the conditions of normal temperature and low voltage.
The mechanism of hard anodization is the result of the simultaneous action of the electrochemical growth and chemical dissolution of the film. Because the hard anodic oxidation film is thick, compact and has higher resistance, in order to obtain the oxidation film with high hardness and thick film layer, the traditional low-temperature single sulfuric acid hard anodic oxidation process adopts high voltage and large current to ensure that the growth speed of the oxidation film is higher than the dissolution speed, the voltage is increased (60V-120V) and the current is increased (the current density is 2.5-4A/dm)2) A large amount of heat is inevitably generated, the temperature of the electrolyte is increased, and the dissolution of the oxide film is accelerated, so that the temperature is reduced by strong refrigeration equipment (-5 ℃).
The method comprises the steps of adding oxalic acid into a sulfuric acid solution, adding lactic acid or malonic acid, increasing the growth speed of an oxide film by utilizing carboxyl and hydroxyl obtained from the oxalic acid, the lactic acid or the malonic acid to be larger than the dissolution speed of the film, obtaining the oxide film with high hardness and thick film layer, and forming the film (1-2A/dm) under the low current condition because the oxide film speed is high enough after the oxalic acid, the lactic acid or the malonic acid is added2) And the film is low in voltage and current, so that the heat released in the film forming process is low, the dissolving speed of the film can not be accelerated, and the film can be formed at normal temperature without strong cooling equipment.
The invention has the beneficial effects that:
the film prepared by the method is compact, uniform, smooth and flat, has a thickness of more than 30 μm and a hardness of not less than 400HV0.05The lubricating property is good, and all the properties are superior to those of a film layer prepared by the traditional low-temperature process.
The process method can work under the condition of normal temperature, only needs common water cooling, does not need forced refrigeration equipment, and can save equipment cost and energy consumption cost for the operation of the forced refrigeration equipment; in addition, the process method has small current and low voltage, can reduce the acquisition cost of power supply equipment, and simultaneously solves the problem of electric energy consumption. In conclusion, the invention can produce economic benefits of reducing equipment cost and saving energy consumption.
Detailed Description
The practice of the method of the present invention is further described below.
The principle of the invention is as follows:
the method comprises the steps of adding oxalic acid into a sulfuric acid solution, adding lactic acid or malonic acid, increasing the growth speed of an oxide film by utilizing carboxyl and hydroxyl obtained from the oxalic acid, the lactic acid or the malonic acid to be larger than the dissolution speed of the film, and obtaining the oxide film with high hardness and thick film layer, wherein the oxide film can be formed under the condition of low current (1-2A/dm) because the oxide film speed is high enough after the oxalic acid, the lactic acid or the malonic acid is added2) Low voltage and currentSmall, the heat released in the film forming process is small, and the dissolving speed of the film can not be accelerated, so that the film can be formed under the normal temperature condition without strong cooling equipment.
A normal-temperature low-voltage hard anodizing process method for aluminum alloy or process flow and process conditions are as follows:
firstly, degreasing the aluminum alloy, (degreasing treatment), wherein the degreasing adopts a bath solution consisting of 20-40 g/L of sodium phosphate and 25-30 g/L of sodium carbonate, the working temperature is 50-70 ℃, and the working time is 40-60 s;
secondly, hot water washing is carried out, tap water is adopted, the working temperature is 50-70 ℃, and the working time is 30 s;
thirdly, washing with cold water, namely adopting tap water, wherein the working temperature is 15-35 ℃, and the working time is 30 s;
fourthly, light extraction is carried out, wherein the bath solution adopted for light extraction comprises 400-500 g/L of nitric acid, the temperature is normal, and the working time is 50-60 s;
fifthly, washing with cold water, namely adopting tap water, wherein the working temperature is 15-35 ℃, and the working time is 30 s;
sixthly, washing with cold water, wherein tap water is adopted, the working temperature is 15-35 ℃, and the working time is 30 s;
seventhly, hard anodizing, wherein the oxidation adopts bath solution, oxalic acid is added into sulfuric acid solution, and then lactic acid or malonic acid is added; 200-300 g/L of sulfuric acid solution, 50-75 g/L of oxalic acid and 50-75 g/L of lactic acid or malonic acid;
the working temperature of the solution is 16-22 ℃, and the soaking working time is 60-70 min; (material electrifying voltage is 20-24V; current density is 0.1 A.dm within the first 20 minutes-2Gradually increased to 0.5 A.dm-2Gradually increasing to 1-2 A.dm within 20-25 minutes-2，)
Controlling the voltage to make the current density within the first 20 minutes from 0.1 A.dm-2Gradually increased to 0.5 A.dm-2Gradually increasing to 1-2 A.dm within 20-25 minutes-2Keeping the temperature to the discharging groove; the oxidation time is 60-70 min.
Eighthly, washing with cold water, namely adopting tap water, wherein the working temperature is 15-35 ℃, and the working time is 30 s;
the ninth step, washing with cold water, wherein tap water is adopted, the working temperature is 15-35 ℃, and the working time is 30 s;
step ten, sealing, wherein the bath solution comprises 4-5 g/L of sealing solution, the working temperature is 20-25 ℃, and the working time is 10-20 min; the corrosion resistance is improved.
Step eleven, washing with cold water, wherein tap water is adopted, the working temperature is 15-35 ℃, and the working time is 30 s;
step ten, hot water washing is carried out, tap water is adopted, the working temperature is 70-90 ℃, and the working time is 30 s;
the thirteen step, drying, namely, blowing the part by using a high-pressure air gun until no obvious water mark exists on the surface of the part;
and step fourteen, drying, wherein the working temperature is 40-80 ℃, and the working time is 5-20 min.
Claims (6)
1. A normal-temperature low-voltage hard anodic oxidation process method for aluminum alloy is characterized in that the oxidation adopts the following solutions: the mixed solution of sulfuric acid solution, oxalic acid, lactic acid or malonic acid has carboxyl and hydroxyl groups in oxalic acid, lactic acid or malonic acid to raise the growth rate of the oxide film to be higher than the dissolving rate of the oxide film.
2. The method as claimed in claim 1, wherein the oxidizing solution is heated at a current of 1-2A/dm2And (5) electrifying to form a film.
3. The normal-temperature low-voltage hard anodizing process method of aluminum alloy as claimed in claim 1,
the oxidizing solution for hard anodizing of the aluminum alloy comprises the following components: sulfuric acid solution, oxalic acid, lactic acid or malonic acid; 200-300 g/L of sulfuric acid solution, 50-75 g/L of oxalic acid and 50-75 g/L of lactic acid or malonic acid;
the solution temperature is 16-22 ℃, and the soaking time is 60-70 min;
the material electrifying voltage is 20-24V;
the current density of the material is controlled from 0.1 A.dm within the first 20 minutes-2Gradually increased to 0.5 A.dm-2；
Gradually increasing to 1-2 A.dm within 20-25 minutes-2The oxidation is kept complete.
4. A normal-temperature low-voltage hard anodizing process method for aluminum alloy is characterized in that an oxidizing solution for hard anodizing the aluminum alloy comprises the following components: sulfuric acid solution, oxalic acid, lactic acid or malonic acid; 200-300 g/L of sulfuric acid solution, 50-75 g/L of oxalic acid and 50-75 g/L of lactic acid or malonic acid.
5. The normal-temperature low-voltage hard anodic oxidation process for aluminum alloy according to claim 4, wherein the solution temperature is 16-22 ℃, and the soaking time is 60-70 min;
the material electrifying voltage is 20-24V;
the current density of the material is controlled from 0.1 A.dm within the first 20 minutes-2Gradually increased to 0.5 A.dm-2；
Gradually increasing to 1-2 A.dm within 20-25 minutes-2The oxidation is kept complete.
6. The normal-temperature low-voltage hard anodizing process method of aluminum alloy as claimed in claim 4 or 5,
firstly, cleaning grease on the surface of an aluminum alloy workpiece;
then, the aluminum alloy is oxidized by the hard anode,
then, washing the parts with water;
then, sealing the aluminum alloy material, wherein a tank liquor is adopted to form 4-5 g/L of sealing liquid, the working temperature is 20-25 ℃, and the working time is 10-20 min;
and finally, washing, drying and drying.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111507102.9A CN114351209A (en) | 2021-12-10 | 2021-12-10 | Normal-temperature low-voltage hard anodizing process method for aluminum alloy |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202111507102.9A CN114351209A (en) | 2021-12-10 | 2021-12-10 | Normal-temperature low-voltage hard anodizing process method for aluminum alloy |
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| CN114351209A true CN114351209A (en) | 2022-04-15 |
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| CN202111507102.9A Pending CN114351209A (en) | 2021-12-10 | 2021-12-10 | Normal-temperature low-voltage hard anodizing process method for aluminum alloy |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114808075A (en) * | 2022-05-27 | 2022-07-29 | 重庆臻宝实业有限公司 | Method for preparing anode film layer with plasma corrosion resistance and low gas overflow amount |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1920109A (en) * | 2006-07-25 | 2007-02-28 | 台山市金桥铝型材厂有限公司 | Preparation technology for horniness anode oxide film of aluminium section bar |
| CN103484913A (en) * | 2013-09-16 | 2014-01-01 | 青岛聚蚨源机电有限公司 | Aluminum alloy hard anodic oxidization treating process |
| CN106400082A (en) * | 2016-12-14 | 2017-02-15 | 玉林师范学院 | Preparation technology of aluminum alloy with surface provided with high-hardness anode oxide film |
-
2021
- 2021-12-10 CN CN202111507102.9A patent/CN114351209A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1920109A (en) * | 2006-07-25 | 2007-02-28 | 台山市金桥铝型材厂有限公司 | Preparation technology for horniness anode oxide film of aluminium section bar |
| CN103484913A (en) * | 2013-09-16 | 2014-01-01 | 青岛聚蚨源机电有限公司 | Aluminum alloy hard anodic oxidization treating process |
| CN106400082A (en) * | 2016-12-14 | 2017-02-15 | 玉林师范学院 | Preparation technology of aluminum alloy with surface provided with high-hardness anode oxide film |
Non-Patent Citations (1)
| Title |
|---|
| 许海华;: "汽车用6063铝合金硬质阳极氧化工艺的研究", 电镀与环保, no. 04, pages 47 - 49 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114808075A (en) * | 2022-05-27 | 2022-07-29 | 重庆臻宝实业有限公司 | Method for preparing anode film layer with plasma corrosion resistance and low gas overflow amount |
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