CN110629212A - Surface treatment liquid for aviation aluminum alloy and use method thereof - Google Patents
Surface treatment liquid for aviation aluminum alloy and use method thereof Download PDFInfo
- Publication number
- CN110629212A CN110629212A CN201810658645.2A CN201810658645A CN110629212A CN 110629212 A CN110629212 A CN 110629212A CN 201810658645 A CN201810658645 A CN 201810658645A CN 110629212 A CN110629212 A CN 110629212A
- Authority
- CN
- China
- Prior art keywords
- aluminum
- based material
- acid
- concentration
- surface treatment
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
- C23C22/34—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing fluorides or complex fluorides
- C23C22/37—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing fluorides or complex fluorides containing also hexavalent chromium compounds
- C23C22/38—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing fluorides or complex fluorides containing also hexavalent chromium compounds containing also phosphates
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/78—Pretreatment of the material to be coated
Abstract
The invention relates to a surface treatment liquid for aviation aluminum alloy and a using method thereof. The treatment liquid is an aqueous acid solution containing chromic acid and CrO3The measured concentration is 35-45 g/L; nitric acid with the concentration of 70-100 g/L; hydrofluoric acid with the concentration of 2-10 g/L; and phosphoric acid with the concentration of 2-10 g/L. The aluminum alloy treatment fluid has long service life and good effect.
Description
Technical Field
The invention belongs to the field of aluminum alloy surface treatment, and particularly relates to an aluminum alloy surface treatment liquid and a surface treatment method.
Background
The chemical conversion coating technology is a technology for forming a stable compound coating on the surface of a metal by chemical or electrochemical means, namely, passivating the metal. The chemical conversion film is mainly used for rust prevention, wear resistance, coating, galvanic corrosion prevention, insulation and decoration of metal. The metal is contacted with a specific corrosive liquid phase, and a chemical reaction is carried out under a certain condition, so that a product film layer with good adhesive force and difficult solubility is formed on the surface of the metal. These film layers either protect the base metal from water and other corrosive media or improve the adhesion and aging resistance of the organic coating film.
In order to obtain a good chemical conversion film, before chemical conversion, surface pretreatment is generally performed.
Disclosure of Invention
In some aspects, there is provided an aluminum-based material surface treatment fluid which is an aqueous acid solution containing,
chromic acid (H)2CrO4) With CrO3The measured concentration is 35-45 g/L;
nitric acid (HNO)3) The concentration is 70-100 g/L;
hydrofluoric acid (HF) with a concentration of 2-10 g/L; and
phosphoric acid (H)3PO4) The concentration is 2-10 g/L.
The surface treating liquid for aluminum-based material is prepared from water, nitric acid, hydrofluoric acid, phosphoric acid and CrO3Is prepared by the following steps.
In some embodiments, the concentration of chromic acid in the aluminum-based material surface treatment solution is 38 to 42 g/L.
In some embodiments, the concentration of nitric acid in the surface treatment liquid for aluminum-based materials is 80 to 90 g/L.
In some embodiments, the concentration of hydrofluoric acid in the surface treatment solution for aluminum-based materials is 4 to 6 g/L.
In some embodiments, the concentration of phosphoric acid in the surface treatment liquid for aluminum-based materials is 4 to 6 g/L.
In some embodiments, the mass ratio of hydrofluoric acid to phosphoric acid in the surface treatment liquid for the aluminum-based material is 0.8 to 1.2: 0.8 to 1.2.
In some embodiments, the mass ratio of hydrofluoric acid to phosphoric acid in the surface treatment liquid for the aluminum-based material is 0.9 to 1.1: 0.9 to 1.1.
In some embodiments, the aluminum-based material surface treatment fluid consists of: chromic acid, nitric acid, hydrofluoric acid, phosphoric acid, and water.
The aluminum-based material surface treatment liquid is an aqueous solution of an acid, wherein the acid is a combination of chromic acid, nitric acid, hydrofluoric acid and phosphoric acid.
In some embodiments, the aluminum-based material surface treatment liquid refers to a solution for surface treatment of an aluminum-based material.
In some embodiments, the pitting ability of the aluminum-based material treatment fluid is tested. For example, the pitting and intergranular corrosion capability test is carried out by using 2024-T3 bare aluminum test piece, namely, the 2024-T3 bare aluminum test piece (the size is 125mm multiplied by 80mm multiplied by 1mm) is placed in the surface treatment liquid of the aluminum-based material, and the test piece is observed after 30 minutes of corrosion. The results show that the surface treatment fluid for aluminum-based materials meets the following criteria: the pitting depth of the end of the crystal grain is not more than 0.025 mm.
In some embodiments, the intergranular corrosion capability of an aluminum-based material treatment fluid is tested. For example, the intergranular corrosion ability test is carried out by using a 2024-T3 bare aluminum test piece, namely, a 2024-T3 bare aluminum test piece (the size is 125mm x 80mm x 1mm) is placed in the surface treatment liquid of the aluminum-based material, and the test piece is observed after 30 minutes of corrosion. The results show that the surface treatment fluid for aluminum-based materials meets the following criteria: no intergranular corrosion or intergranular corrosion depth less than 0.005 mm.
In some embodiments, the frequency of detecting pitting and intergranular corrosion capabilities of the aluminum-based material treatment fluid may be one or more checks per day, week, month, or quarter.
In some aspects, there is provided a use of an aluminum-based material surface treatment liquid for surface treatment of an aluminum-based material.
In some embodiments, the aluminum-based material surface treatment solution is used to pretreat an aluminum-based material to be chemically converted.
In some aspects, a method for pretreating an aluminum-based material is provided, comprising the steps of:
a) an aluminum-based material is immersed in the aluminum-based material surface treatment liquid of the present disclosure.
Optionally, step a) is followed by a step of washing the aluminum-based material with water.
In some embodiments, the aluminum-based material is immersed in the surface treatment solution for 5 to 20 minutes.
In some embodiments, step a) is preceded by the step of mechanically abrading the aluminum-based material.
In some embodiments, step a) is preceded by the step of washing the aluminum-based material with an organic solvent.
In some embodiments, step a) is preceded by the step of washing the aluminum-based material with an alkaline solution.
In some embodiments, step a) is preceded by the step of washing the aluminum-based material with water.
In some embodiments, a method of pretreatment of an aluminum-based material comprises: detecting the corrosion rate of the aluminum-based material surface treatment liquid on the aluminum-based material, and if the corrosion rate is less than 0.020 mm/surface/hour, adding phosphoric acid and hydrofluoric acid into the aluminum-based material surface treatment liquid to enable the corrosion rate to reach 0.020-0.025 mm/surface/hour.
In some embodiments, if the etching rate is less than 0.020 mm/surface/hr, the phosphoric acid and the hydrofluoric acid are added to the aluminum-based material surface treatment liquid at a mass ratio of 0.8 to 1.2: 0.8 to 1.2.
In some embodiments, a method of pretreatment of an aluminum-based material comprises: when the concentration of each component in the surface treatment liquid for aluminum-based materials is detected and the concentration of any component is found to deviate from the recipe, the concentration of the component is adjusted so that the concentration of the component falls within the recipe range.
In some embodiments, the frequency of detecting components may be one or more checks per day, week, month, or quarter.
In some embodiments, when a formula value is a numerical point, deviating from the formula means deviating from the formula value by more than 1%, such as more than 5%, such as more than 10%. When a formula value is a numerical range, deviation from the formula means exceeding the formula numerical range.
In some embodiments, a method of pretreatment of an aluminum-based material comprises: and detecting the concentration of chromic acid and/or nitric acid in the surface treatment solution of the aluminum-based material, and if the concentration of chromic acid and/or nitric acid deviates from the formula, performing the step of adding acid or water to return the concentration of chromic acid and/or nitric acid to the formula range.
In some embodiments, the aluminum-based material pretreatment method further comprises the steps of: detecting the corrosion rate of the aluminum-based material surface treatment liquid to the aluminum-based material, and if the corrosion rate is less than x mm/surface/hour, adding the aluminum-based material surface treatment liquid with the mass ratio of 0.8-1.2: 0.8-1.2 phosphoric acid and hydrofluoric acid, so that the etching rate is more than x mm/surface/hour, wherein x is 0.015-0.025.
In some embodiments, the frequency of detecting the rate of corrosion may be one or more checks per day, week, month, or quarter.
In some embodiments, the aluminum-based material pretreatment method further comprises the steps of: detecting the corrosion rate of the aluminum-based material surface treatment liquid to the aluminum-based material, and if the corrosion rate is less than x mm/surface/hour, adding the aluminum-based material surface treatment liquid with the mass ratio of 0.8-1.2: 0.8 to 1.2 phosphoric acid and hydrofluoric acid, so that the etching rate reaches x to x + y mm/surface/hour, wherein x is 0.015 to 0.025, and y is 0.005 to 0.01.
In some embodiments, the aluminum-based material pretreatment method further comprises the steps of: detecting the corrosion rate of the aluminum-based material surface treatment liquid to the aluminum-based material, and if the corrosion rate is less than 0.020 mm/surface/hour, adding the aluminum-based material surface treatment liquid with the mass ratio of 0.8-1.2: 0.8-1.2 phosphoric acid and hydrofluoric acid to reach a corrosion rate of 0.020-0.025 mm/surface/hour.
In some embodiments, the average daily amount of aluminum-based material treated per 1000 liters of aluminum alloy acid treatment fluid over the trial period is about 5m based on the surface area of the aluminum-based material2Below, for example, about 3m2The following.
In some embodiments, the aluminum-based material surface treatment fluid has a lifetime of 3 months or more, such as 6 months or more, such as 9 months or more, such as 12 months or more, such as 15 months or more, such as 18 months or more, such as 24 months or more.
In some aspects, a method of forming a chemical conversion film on a surface of an aluminum-based material is provided, comprising the steps of:
pretreating an aluminum-based material using the aluminum-based material pretreatment method of the present disclosure;
and immersing the pretreated aluminum-based material into a chemical conversion solution.
In some embodiments, the chemical conversion solution is a liquid capable of forming a good adhesion and insoluble product film on the surface of the aluminum-based material after contacting the aluminum-based material. The chemical conversion solution is, for example, Alodine1200 chemical conversion solution.
In some embodiments, chemical conversion of the aluminum-based material refers to the reaction of the surface of the aluminum-based material with a chemical oxidant in solution in a chemical conversion solution, rather than by applying an electrical voltage to form a chemical conversion film.
In the present invention, unless otherwise specified, scientific and technical terms used herein have the meanings that are commonly understood by those skilled in the art. Also, the laboratory procedures referred to herein are all conventional procedures widely used in the corresponding field. Meanwhile, in order to better understand the present invention, the definitions and explanations of related terms are provided below.
In some embodiments, the aluminum-based material is pure aluminum or an aluminum alloy.
In some embodiments, the aluminum alloy is a 1XXX series aluminum alloy, i.e., greater than 99% pure aluminum series, such as 1050, 1100; 2XXX series aluminum alloys, i.e., the aluminum-copper alloy series, such as 2014; 3XXX series aluminum alloys, i.e., aluminum-manganese alloy series, such as 3003; 4XXX series aluminum alloys, i.e., aluminum-silicon alloy series, such as 4032; 5XXX series aluminum alloys, i.e., aluminum-magnesium alloy series, such as 5052; 6XXX series aluminum alloys, i.e., aluminum-magnesium-silicon alloy series, such as 6061, 6063; 7XXX series aluminum alloys, i.e., aluminum-zinc alloy series aluminum alloys, such as 7001; 8XXX series aluminum alloys, i.e., alloy systems other than those described above.
In some embodiments, the aluminum alloy refers to a 2XXX series aluminum alloy, such as the aluminum alloys having designations 2024, 2a16(LY16), or 2a02(LY 6).
In some embodiments, the aluminum alloy is an aerospace aluminum alloy.
In some embodiments, the aluminum content in the aluminum alloy is greater than or equal to 50 wt.%, such as greater than or equal to 60 wt.%, such as greater than or equal to 70 wt.%, such as greater than or equal to 80 wt.%, such as greater than or equal to 90 wt.%, such as greater than or equal to 95 wt.%, such as greater than or equal to 99 wt.%.
The corrosion rate of the aluminum alloy acid treatment liquid to the test piece is controlled to be 0.020-0.025 mm/surface/hour by adding hydrofluoric acid and phosphoric acid (optionally, the mass ratio of the hydrofluoric acid to the phosphoric acid is 0.8-1.2-0.8-1.2) to the aluminum alloy acid treatment liquid (the test piece material is 2024-T3 aluminum-coated test piece).
The 2024-T3 aluminum clad test pieces are industry standard test pieces well known in the art. The method is characterized in that a high-purity aluminum layer with the thickness not less than 4% is metallurgically bonded on the surface of the 2024 aluminum alloy and is used as an anode of the core alloy to improve the corrosion resistance of the core alloy.
2024-T3 bare aluminum coupons are industry standard coupons known in the art. It is an aluminum alloy with an outer layer not containing an aluminum coating layer.
Chromic acid is H2CrO4From CrO3Dissolving in water. The nitric acid is HNO3. Phosphoric acid is H3PO4. The hydrofluoric acid is HF.
Advantageous effects
The present disclosure has one or more of the following benefits:
1. the aluminum-based material surface treatment liquid has long service life, for example, up to two years;
2. the pretreatment method for the surface of the aluminum-based material has good effect, if intergranular corrosion does not occur;
3. the surface chemical conversion treatment effect of the aluminum-based material is good, such as no corrosion point in a salt spray test;
4. the method for pretreating the surface of the aluminum-based material has low cost, and the treatment liquid is continuously used without frequently replacing the treatment liquid;
5. the chemical conversion treatment cost of the surface of the aluminum-based material is low.
Embodiments of the present invention will be described in detail below with reference to the drawings and examples, but those skilled in the art will understand that the following drawings and examples are only for illustrating the present invention and are not to be construed as limiting the scope of the present invention. Various objects and advantageous aspects of the present invention will become apparent to those skilled in the art from the accompanying drawings and the following detailed description of the preferred embodiments.
Drawings
FIG. 1 is a photograph of test pieces of 9 th and 10 th aluminum alloys of comparative example 2;
FIG. 2 is a photograph of the 9 th and 10 th aluminum alloy test pieces of example 2;
FIG. 3 is a photograph of the 30 th and 31 th aluminum alloy test pieces of comparative example 2;
FIG. 4 is a photograph of the 30 th and 31 th aluminum alloy test pieces of example 2;
FIG. 5 is a metallographic picture (magnification 500) of an aluminum alloy test piece treated with the aluminum alloy acid treatment solution of example 1;
FIG. 6 is a photograph of the aluminum alloy test piece of example 3 after being subjected to a salt spray test.
Detailed Description
Embodiments of the present invention will be described in detail below with reference to examples, but those skilled in the art will appreciate that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.
Comparative example 1
The aluminum alloy acid treatment liquid A is an aqueous acid solution and consists of chromic acid, nitric acid and hydrofluoric acid, wherein: chromic acid (in CrO)3Calculated) 40g/L, 85g/L nitric acid and 5g/L hydrofluoric acid, and the total amount is 2L.
Example 1
The aluminum alloy acid treatment solution B is an acid aqueous solution and consists of chromic acid, nitric hydrofluoric acid and phosphoric acid, wherein: chromic acid (in CrO)3Calculated) 40g/L, 85g/L nitric acid, 5g/L hydrofluoric acid and 5g/L phosphoric acid, and the total amount is 2L.
Chemical conversion acceleration test
Comparative example 2
For the accelerated aging test, 5 bare aluminum test pieces (125 mm. times.80 mm. times.1 mm in size) 2024-T3 were placed in 2 liters of the aluminum alloy acid-treated solution A and left for 1.5 hours. And taking out the bare aluminum test piece to obtain the aged aluminum alloy acid treatment solution A.
The test pieces were pretreated with the aged aluminum alloy acid treatment solution A, and the test pieces were 2024-T3 bare aluminum test pieces (125 mm. times.80 mm. times.1 mm in size). The acid-treated coupon was then chemically converted. The method comprises the following specific steps:
a) organic oil removal: wiping the test piece with absorbent cotton dipped with acetone or butanone to remove grease on the surface of the test piece;
b) cleaning with alkaline cleaning solution: putting the test piece into an alkaline cleaning solution (TURCO4215 solution) for cleaning;
c) spraying and water washing: the test piece was sprayed with deionized water. Checking the continuity of the water film, checking whether the water film is not broken continuously within 30 seconds, if not, repeating the first step and the second step until the water film is not broken continuously within 30 seconds;
d) acid treatment: stirring the aluminum alloy acid treatment solution in advance, immersing the test piece in the aluminum alloy acid treatment solution for 10 minutes, and continuously stirring the aluminum alloy acid treatment solution;
e) spraying and water washing: spraying deionized water on the test piece to remove the aluminum alloy acid treatment liquid on the test piece;
f) washing with water: soaking the test piece into deionized water for cleaning;
chemical conversion: the test pieces were immersed in a chemical conversion solution (Henkel, Alodine1200) for 2 minutes;
g) spraying and water washing: spraying the test piece with deionized water to remove the chemical conversion solution on the surface of the test piece;
h) washing with water: soaking the test piece into deionized water for cleaning;
i) drying: the test piece was dried with clean compressed air to complete the chemical conversion treatment.
Repeating the steps a) to j) to process the next test piece.
After the 10 th test piece is treated, the corrosion rate of the test piece by the aluminum alloy acid treatment liquid A is detected to be 0.017 mm/surface/hour. Hydrofluoric acid (4 ml) of hydrofluoric acid (40% by weight in concentration) was added to the aluminum alloy acid treatment liquid a so that the corrosion rate of the aluminum alloy acid treatment liquid a reached 0.024 mm/surface/hr. Then, the next test piece is processed.
Example 2
The procedure of the aluminum alloy chemical conversion accelerated test parameters was the same as in comparative example 2 except that the aluminum alloy acid treatment solution A was replaced with an aluminum alloy acid treatment solution B.
After the 10 th test piece is treated, the corrosion rate of the aluminum alloy acid treatment liquid B on the test piece is detected to be 0.015 mm/surface/hour. To the aluminum alloy acid-treating liquid B was added 4ml of hydrofluoric acid (concentration: 40% by weight, 1.12 g/cm)3) And 1.5ml of phosphoric acid (concentration 85% by weight, 1.69 g/cm)3) Corresponding to HF and H3PO4The mass ratio is 1: 1.2. the corrosion rate of the aluminum alloy acid treatment liquid A reaches 0.024 mm/surface/hour. Then, the next test piece is processed.
Analysis of results of aluminum alloy chemical conversion acceleration test (comparative example 2 and example 2)
(1) When the test pieces are processed to 9 th and 10 th test pieces
FIG. 1 shows the 9 th and 10 th test pieces obtained by the treatment of comparative example 2, FIG. 2 shows the 9 th and 10 th test pieces obtained by the treatment of example 2, and in FIGS. 1 and 2, the left test piece is the 9 th test piece and the right test piece is the 10 th test piece.
As shown in the figure, the test piece (pretreated with the aluminum alloy acid treatment liquid A) of comparative example 2 had an uneven chemical oxide film layer on the surface. The surface of the test piece of example 2 (pretreated with the aluminum alloy acid treatment solution B) was chemically oxidized to form a uniform film layer.
(2) When processing 30, 31 test pieces
Fig. 3 shows the 30 th and 31 th test pieces treated in comparative example 2, fig. 4 shows the 30 th and 31 th test pieces treated in example 2, and in fig. 3 and 4, the left side test piece is the 30 th test piece, and the right side test piece is the 31 th test piece. As shown in the figure, the test piece of FIG. 3 (pretreated with the aluminum alloy acid treatment solution A) had a chemical oxide film only partially after chemical conversion. The test piece of FIG. 4 (pretreated with the aluminum alloy acid treatment solution B) had a uniform chemical oxide film on the entire surface after chemical conversion.
From the above experimental results, it is understood that the aluminum alloy treatment liquid of comparative example 1 has a short pot life, and after a certain period of use, the surface of the aluminum alloy cannot be effectively treated, and thus an acceptable chemical conversion coating cannot be obtained. The aluminum alloy treating fluid of example 1 has a longer service life, and can effectively treat the surface of the aluminum alloy when the aluminum alloy treating fluid is used for treating 31 test pieces, so that an acceptable chemical conversion coating is obtained.
Second, testing the end point pitting and intergranular corrosion of crystal grains
For the newly prepared and aged aluminum alloy acid-treated liquid B of example 1, 2024-T3 bare aluminum test pieces (having dimensions of 125 mm. times.80 mm. times.1 mm) were placed in the aluminum alloy acid-treated liquid B, and the test pieces were observed after etching for 30 minutes. FIG. 5 shows a metallographic picture of the aluminum alloy test piece, as shown in the figure, only 0.017mm of grain end pitting corrosion is observed on the test piece, and no intergranular corrosion is observed.
Three, constant speed (non-accelerated aging) chemical conversion production
Example 3
In the chemical conversion production at the constant speed, 9000 liters of the aluminum alloy acid treatment solution was used in the formulation of the aluminum alloy acid treatment solution B in example 1, and the aluminum alloy chemical conversion treatment was performed in accordance with the steps a) to j) of example 2, and the aluminum alloy part was treated at about 24m per day in terms of the surface area of the aluminum alloy part2。
In the chemical conversion production process, a 2024-T3 aluminum-coated test piece is used for corrosion rate test, and if the corrosion rate of the aluminum alloy acid treatment liquid to the test piece is less than 0.020 mm/surface/hour, phosphoric acid and hydrofluoric acid with the mass ratio of 1:1.2 are added into the aluminum alloy acid treatment liquid B, so that the corrosion rate reaches 0.020-0.025 mm/surface/hour.
The pitting corrosion and intergranular corrosion capability test is carried out by using 2024-T3 bare aluminum test pieces every season, namely, the 2024-T3 bare aluminum test pieces (the size is 125mm multiplied by 80mm multiplied by 1mm) are placed in the aluminum alloy acid treatment solution B, and the test pieces are observed after 30 minutes of corrosion. The results show that the aluminum alloy treatment liquid of the present example satisfies: the pitting depth of the end of the grain is not more than 0.025mm and no intergranular corrosion exists.
And analyzing and adjusting other chemical components except phosphoric acid and hydrofluoric acid in the aluminum alloy treatment solution every week to enable the components to meet formula values.
Chemical conversion film integrity test: after 2 years (730 days) of continuous use of the above solution, a chemical conversion test was carried out using a bare aluminum test piece 2024-T3, and the entire surface of the chemically converted test piece had a uniform chemical oxide film.
And (3) salt spray testing: 3 test pieces after the above chemical conversion were left for 24 hours and subjected to a salt spray test for 168 hours according to ASTM B117 salt spray test standards. FIG. 6 is a photograph showing 3 specimens of the aluminum alloy, in which no corrosion spots were observed after the test.
The above experiment shows that the aluminum alloy treatment liquid of example 1 has an advantage of a longer cycle time than the aluminum alloy treatment liquid of comparative example 1. The aluminum alloy treatment liquid of example 1 was excellent in the effect of treating an aluminum alloy and did not cause intergranular corrosion. And (3) carrying out chemical conversion on the treated aluminum alloy, wherein the obtained chemical conversion film is complete and has no corrosion point after a salt spray test.
While specific embodiments of the invention have been described in detail, those skilled in the art will understand that: various modifications and changes in detail can be made in light of the overall teachings of the disclosure, and such changes are intended to be within the scope of the present invention. The full scope of the invention is given by the appended claims and any equivalents thereof.
Claims (12)
1. A surface treatment liquid for an aluminum-based material, which is an aqueous acid solution, contains,
chromic acid, in CrO3The measured concentration is 35-45 g/L;
nitric acid with the concentration of 70-100 g/L;
hydrofluoric acid with the concentration of 2-10 g/L; and
the concentration of the phosphoric acid is 2-10 g/L.
2. The surface treatment fluid for aluminum-based materials as claimed in claim 1, which has one or more of the following characteristics:
the concentration of chromic acid is 38-42 g/L;
the concentration of the nitric acid is 80-90 g/L;
the concentration of the hydrofluoric acid is 4-6 g/L;
the concentration of the phosphoric acid is 4-6 g/L;
the mass ratio of the hydrofluoric acid to the phosphoric acid is 0.8-1.2: 0.8 to 1.2;
the aluminum-based material is pure aluminum or an aluminum alloy.
3. The surface treatment liquid for aluminum-based materials as claimed in claim 1, which is composed of:
chromic acid, nitric acid, hydrofluoric acid, phosphoric acid, and water.
4. Use of the surface treatment liquid for aluminum-based materials according to any one of claims 1 to 3 for surface treatment of aluminum-based materials.
5. The use according to claim 4, for the pretreatment of an aluminum-based material to be chemically converted.
6. A method for pretreating an aluminum-based material, comprising the steps of:
a) immersing an aluminum-based material in the surface treatment liquid for an aluminum-based material according to any one of claims 1 to 5;
optionally, step a) is followed by a step of washing the aluminum-based material with water.
7. The method for pretreating aluminum-based materials of claim 6, wherein,
and soaking the aluminum-based material in the aluminum-based material surface treatment solution for 5-20 minutes.
8. The method for pretreating aluminum-based materials according to claim 7, further comprising, prior to step a), one or more of:
-mechanically grinding the aluminum-based material;
-washing the aluminum-based material with an organic solvent;
-washing the aluminum-based material with an alkaline solution;
washing the aluminum-based material with water.
9. The method for pretreatment of aluminum-based materials as claimed in claim 6, further comprising one or more of:
detecting the corrosion rate of the aluminum-based material surface treatment liquid on the aluminum-based material, and if the corrosion rate is less than x mm/surface/hour, adding phosphoric acid and hydrofluoric acid into the aluminum-based material surface treatment liquid to enable the corrosion rate to reach more than x mm/surface/hour, wherein x is 0.015-0.025;
detecting the concentration of each component in the aluminum-based material surface treatment liquid, and if the concentration of any component is found to deviate from the formula, performing an operation of adjusting the concentration of the component so that the concentration of the component is brought back into the formula range.
10. The aluminum-based material pretreatment method of claim 9, having one or more of the following characteristics:
the mass ratio of phosphoric acid to hydrofluoric acid added to the aluminum-based material surface treatment liquid is 0.8-1.2: 0.8 to 1.2;
-detecting the concentration of chromic acid and/or nitric acid in the surface treatment liquid for the aluminum-based material, and if the concentration of chromic acid and/or nitric acid deviates from the recipe, performing the step of adding acid or water to bring the concentration of chromic acid and/or nitric acid back into the recipe range
The aluminum-based material is aluminum or an aluminum alloy, such as a 2XXX series aluminum alloy.
11. The method for pretreating an aluminum-based material according to claim 9, wherein the surface treatment liquid for an aluminum-based material has a lifetime of 3 months or more.
12. A method for forming a chemical conversion coating on the surface of an aluminum-based material, comprising the steps of:
pretreating an aluminium-based material using a method according to any one of claims 6 to 11;
and immersing the pretreated aluminum-based material into a chemical conversion solution.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810658645.2A CN110629212B (en) | 2018-06-25 | 2018-06-25 | Surface treatment liquid for aviation aluminum alloy and use method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810658645.2A CN110629212B (en) | 2018-06-25 | 2018-06-25 | Surface treatment liquid for aviation aluminum alloy and use method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110629212A true CN110629212A (en) | 2019-12-31 |
| CN110629212B CN110629212B (en) | 2021-09-21 |
Family
ID=68967475
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810658645.2A Active CN110629212B (en) | 2018-06-25 | 2018-06-25 | Surface treatment liquid for aviation aluminum alloy and use method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110629212B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4812175A (en) * | 1985-09-06 | 1989-03-14 | Parker Chemical Company | Passivation process and copmposition for zinc-aluminum alloys |
| CN101935884A (en) * | 2009-07-02 | 2011-01-05 | 比亚迪股份有限公司 | Method for preparing textured polycrystalline silicon wafer |
| WO2014007577A1 (en) * | 2012-07-06 | 2014-01-09 | ㈜코이즈 | Method for producing diffuser sheet having irregular shapes, and diffuser sheet produced by the method |
| CN104372358A (en) * | 2014-10-31 | 2015-02-25 | 上海飞机制造有限公司 | Method for detecting aircraft aluminum alloy surface cleaning composition |
| CN104404487A (en) * | 2014-11-19 | 2015-03-11 | 广州立铭环保科技有限公司 | Passivator and preparation method thereof |
| CN106238850A (en) * | 2016-08-31 | 2016-12-21 | 浙江长兴电子厂有限公司 | A kind of welding procedure of ceramic insulator metal shell |
-
2018
- 2018-06-25 CN CN201810658645.2A patent/CN110629212B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4812175A (en) * | 1985-09-06 | 1989-03-14 | Parker Chemical Company | Passivation process and copmposition for zinc-aluminum alloys |
| CN101935884A (en) * | 2009-07-02 | 2011-01-05 | 比亚迪股份有限公司 | Method for preparing textured polycrystalline silicon wafer |
| WO2014007577A1 (en) * | 2012-07-06 | 2014-01-09 | ㈜코이즈 | Method for producing diffuser sheet having irregular shapes, and diffuser sheet produced by the method |
| CN104372358A (en) * | 2014-10-31 | 2015-02-25 | 上海飞机制造有限公司 | Method for detecting aircraft aluminum alloy surface cleaning composition |
| CN104404487A (en) * | 2014-11-19 | 2015-03-11 | 广州立铭环保科技有限公司 | Passivator and preparation method thereof |
| CN106238850A (en) * | 2016-08-31 | 2016-12-21 | 浙江长兴电子厂有限公司 | A kind of welding procedure of ceramic insulator metal shell |
Non-Patent Citations (1)
| Title |
|---|
| 李龙 等: "金属复合板表面处理技术的研究现状及发展", 《表面技术》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110629212B (en) | 2021-09-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Golru et al. | Morphological analysis and corrosion performance of zirconium based conversion coating on the aluminum alloy 1050 | |
| Fahrenholtz et al. | Characterization of cerium-based conversion coatings for corrosion protection of aluminum alloys | |
| Lunder et al. | Effect of pre-treatment on the durability of epoxy-bonded AA6060 aluminium joints | |
| US7922889B2 (en) | Anodising aluminum alloy | |
| EP1874980B1 (en) | Process for forming a well visible non-chromate conversion coating for magnesium and magnesium alloys | |
| FR2986806A1 (en) | PROCESS FOR SURFACE TREATMENT OF ALUMINUM ALLOY OR MAGNESIUM ALLOYS | |
| US20230002877A1 (en) | Method for Producing a Flat Steel Product Having a Protective Zinc-Based Metal Layer and a Phosphating Layer Produced on a Surface of the Protective Metal Layer and Flat Steel Product of This Type | |
| Liu et al. | Protection of AA5083 by a zirconium-based conversion coating | |
| US5683522A (en) | Process for applying a coating to a magnesium alloy product | |
| WO2021152240A1 (en) | Method for the surface treatment of aluminium-based parts | |
| Šekularac et al. | Comparison of the Electrochemical Behaviour and Self-sealing of Zirconium Conversion Coatings Applied on Aluminium Alloys of series 1xxx to 7xxx | |
| JP2002294466A (en) | Conversion coating solution for magnesium alloy, surface treatment method, and magnesium-alloy base material | |
| US5582654A (en) | Method for creating a corrosion-resistant surface on aluminum alloys having a high copper content | |
| JP5183062B2 (en) | Surface treatment method for aluminum alloy plates and strips | |
| CN102762768A (en) | Magnesium-lithium alloy and surface treatment method therefor | |
| Howlett et al. | Conversion coatings of Mg-alloy AZ91D using trihexyl (tetradecyl) phosphonium bis (trifluoromethanesulfonyl) amide ionic liquid | |
| CN110629212B (en) | Surface treatment liquid for aviation aluminum alloy and use method thereof | |
| CA2446995C (en) | Composition and method for treating magnesium alloys | |
| Kok et al. | Formation of zinc phosphate coatings on AA6061 aluminum alloy | |
| US8262810B2 (en) | Method for conversion treating surface of magnesium alloy workpiece | |
| Lunder et al. | Pretreatment of aluminum alloy 6060 by selective removal of surface intermetallics | |
| US5635084A (en) | Method for creating a corrosion-resistant surface on an aluminum-copper alloy | |
| CN109207972A (en) | A kind of preparation method of aluminum alloy surface titanium zirconium cerium chemical composition coating | |
| JPWO2019031078A1 (en) | Metal connecting member and chemical conversion treatment method for metal connecting member | |
| RU2334021C1 (en) | Method for obtaining protective coating on products from magnesium alloys |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |