JP2000038683A - Aluminum alloy treated plate and its manufacturing method - Google Patents

Abstract

(57) [Problem] To provide an aluminum alloy treated plate having a surface excellent in formability and adhesion after painting at low cost. SOLUTION: An inorganic compound particle having a particle diameter of 0.001 to 5 μm is optionally coated on one or both surfaces.
Measured in μm ² , a coating area ratio of 20 to 80% was adhered, phosphate: 0.8 to 3.0 g / m ² , fluorine: 5
It is characterized by having a coating containing 0 mg / m ² or less and Na: 25 mg / m ² or less and having a weight ratio of zinc to phosphorus (zinc / phosphorus) of 2.5 to 4.5. Aluminum alloy treated plate excellent in formability and adhesion after painting, and a method for producing the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating an aluminum alloy material used for painting and used as a body of an automobile or a housing of a home electric appliance, and an aluminum alloy having excellent moldability and adhesion after painting. It relates to an alloy-treated plate.

[0002]

2. Description of the Related Art Conventionally, cold-rolled steel sheets have been mainly used as body sheets for automobile bodies, but aluminum alloys have recently been adopted for the purpose of weight reduction. As the aluminum alloy material to be used, Mg-containing aluminum alloys such as 5xxx, 6xxx, and 7xxx are used. The body sheet of this car body is made into a target shape by press molding etc. of a steel plate or aluminum alloy plate manufactured by a material maker at an automobile maker, joined and assembled, treated with zinc phosphate, electrodeposition coating, intermediate coating And a process of applying a top coat. In addition, it is required that both the steel plate and the aluminum alloy plate can be processed by the same equipment and the same process.

[0003] Therefore, as for the press formability, it is required that the aluminum alloy sheet is as excellent in forming work as the steel sheet, that it has little mold seizure in forming work and that it is not easily damaged. Further, since the steel plate and the aluminum alloy plate are simultaneously processed in the zinc phosphate treatment after assembly, equipment, a treatment bath, a method or an aluminum alloy plate suitable for the treatment are required. Furthermore, if the zinc phosphate film is insufficient, the adhesion after painting may not be ensured, and sufficient adhesion after painting has been required.

[0004] However, aluminum alloy plates have the drawbacks that they have less elongation than steel plates, are inferior in forming workability, and have a soft surface, so that they are easily damaged during handling and pressing, and are liable to be galling. There was a problem. For this reason, conventionally, high viscosity lubricant must be used at the time of press molding, frequent maintenance of the press mold is required, and a protective resin sheet is required, such as a decrease in productivity, In addition, the cost is increased.

[0005] In addition, since a treatment bath is used to apply a zinc phosphate film to a steel plate and an aluminum alloy plate at the same time, a sufficient zinc phosphate treatment film is not applied to an aluminum alloy plate having poor zinc phosphate treatability. There was a problem that did not generate. In order to solve this, measures have been taken such as increasing the fluorine ion concentration in the zinc phosphate treatment bath to increase the reactivity. However, there were problems in terms of cost, work environment, and the like. Further, when the treatment is carried out in a treatment bath having an increased concentration of fluorine ions, there is a problem that the fluorine compound increases in the zinc phosphate film and the adhesion after coating is poor.

As means for solving these problems, JP-A-6-2
Japanese Patent No. 5866 proposes a rolled aluminum alloy plate having a phosphate coating on at least 50% of the surface area of the rolled aluminum alloy plate. However, JP
In the case of Japanese Patent No. 25866, the adhesion after coating is sufficient because the phosphate film coated with a coating rate of 50% or more and the chemical conversion coating film of an automobile manufacturer contain considerable fluorine. I can't secure it. From such a thing,
With regard to an aluminum alloy sheet for forming used in an automobile body, an aluminum alloy sheet having good formability, coating chemical conversion property, and corrosion resistance after painting has been desired.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art in an aluminum alloy plate and to reduce the cost of the aluminum alloy treated plate having a surface excellent in formability and adhesion after painting. It is to provide in.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above problems and attain the above object, and as a result, the present invention has been accomplished. (1) The particle diameter is 0.001 on one or both surfaces.
５5 μm of inorganic compound particles are measured at an arbitrary 100 μm ² , and after covering 20 to 80% of the coating area ratio, phosphate: 0.8 to 3.0 g / m ² , fluorine: 50 mg / m 2
² or less, Na: 25 mg / m ² or less, and the content ratio of zinc to phosphorus (zinc / phosphorus) is 2.5 to 2.5% by weight.
An aluminum alloy treated plate excellent in formability and adhesion after painting, characterized by having a coating of 4.5.

(2) The inorganic compound is titanium oxide, nickel oxide, magnesium oxide, tungsten oxide, niobium oxide, aluminum oxide, zinc oxide, cuprous oxide, cupric oxide, ferric oxide, molybdenum oxide, water It is characterized by being one or a mixture of two or more selected from magnesium oxide, nickel hydroxide, magnesium carbonate, calcium carbonate, zinc phosphate, magnesium oxalate, barium titanate, calcium silicate, and magnesium hydrogen phosphate. An aluminum alloy-treated plate having excellent moldability and adhesion after painting according to (1).

(3) 0.01-50 w of inorganic compound particles
The inorganic compound particles are adhered by applying a suspension containing t% and rubbing before the suspension is dried. Then, Zn ions: 0.5 to 10 g / l, PO ₄
Ion: 5.0~40g / l, NO ₃ ion: 0.5
The method for producing an aluminum alloy-treated plate having excellent moldability and adhesion after coating according to the above (1) or (2), wherein the plate is treated with an aqueous solution containing 10 g / l and 30 to 400 ppm of free fluorine. is there.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An aluminum alloy material for this purpose usually takes a process of molding, assembling, alkali degreasing and phosphate treatment after being delivered from an aluminum material manufacturer to an automobile body manufacturer. By forcibly attaching the inorganic compound of the metal to the surface of the aluminum alloy material as in the method of the present invention, the subsequent Zn ions, PO ₄ ions,
Increases reactivity when treated with an aqueous solution containing NO ₃ ions and free fluorine. This is considered to be because the presence of the inorganic compound on the surface of the aluminum alloy serves as a nucleus for film formation and promotes the reaction.

Therefore, the inorganic compound of the metal used in the present invention includes titanium oxide, nickel oxide, magnesium oxide, tungsten oxide, niobium oxide, aluminum oxide, zinc oxide, cuprous oxide, cupric oxide, and copper oxide. Nitetsu,
Molybdenum oxide, magnesium hydroxide, nickel hydroxide, magnesium carbonate, calcium carbonate, zinc phosphate,
Examples thereof include magnesium oxalate, barium titanate, calcium silicate, magnesium hydrogen phosphate, and the like. One of these may be used, or two or more thereof may be used in combination.

The coverage of the particles of the metal inorganic compound is 20 to 80% as measured at an arbitrary 100 μm ² . If it is less than 20%, the particle coverage is low and the effect of accelerating film formation is small.
On the other hand, when the coverage of the particles of the metal inorganic compound exceeds 80%, the particles are continuously formed into large agglomerates, and the number of nucleus sites for film formation is too small, and the film is not sparsely formed, which is not preferable. . The particles of the inorganic compound of the metal are attached to the surface of the aluminum material in an arbitrary 100 μm.
The method for measuring the m ² and having a coverage of 20 to 80% is as follows. First, a suspension of an inorganic compound of these metals is deposited. This is done by spraying the suspension onto the aluminum alloy or dipping the aluminum alloy into the suspension. By attaching the suspension to the plate surface using the suspension, uniform attachment can be achieved.

If the particles of the inorganic compound of the metal are rubbed against the surface of the aluminum alloy material as a powder without using a suspension, the particles cannot be uniformly adhered, and also the surface of the aluminum plate is damaged. Therefore, the metal inorganic compound needs to be a substance that becomes a suspension. Further, the particle size distribution of the inorganic compound of the metal suspended in the liquid may extend over a wide range, but since the particles of 0.0010 to 5 μm are considered to exhibit the above-mentioned action, they adhered to the surface of the aluminum alloy plate. The particle size range of the metal inorganic compound is set to this range. When the particle size is less than 0.0010 μm, no effect of promoting the reaction of film formation is observed. If the particle size exceeds 5 μm, the particles exceeding 5 μm will adhere to the surface of the aluminum alloy material when the film is formed, and the adhesion after final coating will be poor. For the same reason as above, the particle size of the inorganic compound of the metal is preferably 0.0050 to 3 μm,
More preferably, the thickness is from 00 to 1 μm.

As described above, it is considered that the particles of the metal inorganic compound having a particle size of 0.0010 to 5 μm exert the above-mentioned effect. However, since the particles are reduced by suspending in a liquid or rubbing as described below. Alternatively, the particle size distribution before suspension in the liquid may extend over a wide range. Thereafter, the inorganic compound particles are forcibly attached by rubbing in a state where the inorganic compound particles are not completely dried. By rubbing in a state where it is not completely dried, compared to rubbing in a completely dry state, the surface of the plate is less likely to be scratched and can be evenly and uniformly attached.

In this specification, "rubbing"
The term “operation” refers to an operation of mechanically rubbing particles to adhere to the surface of an aluminum material. Specific examples include brushing using a plan roll, light pressure using a rubber roll or a sponge, buff polishing using a polishing cloth, and the like. The suspension used contains 0.01% to 50% of a metal inorganic compound.
At a concentration of If the concentration of the inorganic compound is less than 0.01%, the particle coverage is low, and the effect as a nucleus for promoting film formation is small. If the concentration is more than 50%, not only the cost becomes high but also the particle coverage becomes too high and the particles are continuously generated, so that the number of nucleus sites for film formation becomes too small and the film is sparsely formed. Not preferred. Therefore, the concentration is set to 0.01% to 50%, but more preferably 0.1% to 10% for the same reason.

In the present invention, a phosphate film is provided on the surface of the aluminum alloy-treated plate, and the amount of fluorine in the film must be 50 mg / m ² or less and the amount of Na must be 25 mg / m ² or less. When the amount of fluorine exceeds 50 mg / m ² or the amount of Na exceeds 25 mg / m ² , the adhesion after coating deteriorates. This is because sodium- and fluorine-containing compounds such as cryolite (Na ₃ AlF ₆ ) are taken into the phosphate film, and they are easily dissolved in water. , Adhesion cannot be ensured after coating.

The surface of the present invention contains zinc and phosphorus in a weight ratio (zinc / phosphorus) of 2.5 to 4.5, and has a fluorine content of 50 mg / m ² or less and a Na content of 25 mg / m ² or less. In order to manufacture an aluminum alloy-treated plate having a phosphate of 0.8 to 3.0 g / m ² , Zn ions;
~10g / l, PO ₄ ion; 5.0~40g / l, N
It can be produced by immersing an aluminum alloy plate in an aqueous solution containing O ₃ ions: 0.5 to 10 g / l and containing free fluorine of 30 to 400 ppm or less.

When the concentration of zinc ions in the treatment solution is 0.5
If the amount is less than g / l, it is difficult to perform the treatment in a short time, and if it exceeds 10 g / l, the treatment can be performed in a short time, but wasteful chemicals are consumed, which is economically disadvantageous. In addition, PO ₄
When the amount of ions is less than 5.0 g / l, it is difficult to perform the treatment in a short time. When the amount exceeds 40 g / l, the treatment can be performed in a short time, but wasteful chemicals are consumed, which is economically disadvantageous. On the other hand, if the NO ₃ ion is less than 0.5 g / l, it is difficult to perform the treatment in a short time, and if it exceeds 10 g / l, the effect of the treatment in a short time is saturated and wasteful chemicals are consumed. Economically disadvantaged. In addition, free fluorine is 30p
When the viscosity is less than pm, the reactivity is low, and the treatment in a short time becomes difficult. If the free fluorine exceeds 400 ppm, fluorine and Na are likely to be taken into the film, which is not preferable.

In the present invention, the phosphate film formed on the aluminum alloy plate needs to contain zinc and phosphorus in a weight ratio (zinc / phosphorus) of 2.5 to 4.5. When the weight ratio of zinc and phosphorus (zinc / phosphorus) exceeds 4.5, the reactivity of the zinc phosphate treatment is low, and it is difficult to perform the treatment in a short time. On the other hand, if it is less than 2.5, the treatment effect in a short time is saturated and wasteful chemicals are consumed, which is economically disadvantageous. Furthermore, it is preferable to appropriately add the following properties to the film of the aluminum-treated plate of the present invention, whereby
The most suitable aluminized plate can be provided according to the material and application.

In the present invention, the aluminum alloy plate is made of M
In the case of a g-containing alloy plate, the amount of phosphate on the surface is 0.8
-3.0 g / m < ² > is preferable. If it is less than 0.8 g / m ² , the moldability is not sufficiently improved. Since the phosphate film has lubricity and hardness, the effect of applying the lubricating film on the aluminum alloy treated plate is exhibited, and the surface is hardened to be hardly damaged. On the other hand, if it exceeds 3.0 g / m ² , powdering occurs at the time of molding, a film adheres to the molding die, and the maintenance work of the die increases, which is not preferable.
It should be noted that, by applying press oil, wax or the like to the Mg-containing aluminum alloy-treated plate, the formability can be further improved.

Further, the coverage of phosphate on the surface of the aluminum alloy treated plate is not particularly limited, but is preferably higher. As the coverage increases, the elution of aluminum ions during the coating conversion treatment can be suppressed, so that the formation of a coating is less likely to be inhibited during the coating conversion treatment of the steel sheet when the aluminum alloy plate is treated simultaneously with the steel sheet. In addition, since the aluminum alloy-treated plate has phosphate on the surface, the contact resistance increases and the weldability is improved as compared with the untreated plate. However, if the coating amount is too large, the resistance is too high and the effect is adverse. Therefore, when welding is used as essential, the upper limit of the coating amount is appropriately determined according to the welding conditions.

When the aluminum alloy treated plate is stored until used by a user, it is preferable to form an oil layer on the surface. By forming an oil layer,
The deterioration with time of the surface is improved. As the oiling amount of the oil layer,
The effect is sufficient if there is an oil layer of 0.1 g / m ² . The component composition of the aluminum alloy material to which the present invention is applied is not particularly limited as long as it is subjected to a phosphate treatment and used for coating purposes, and various aluminum alloys can be used. In particular, in the case of the use of an automobile body, which is a main object of the present invention, an Al-Mg alloy (JLS5000 alloy) and an Al-Mg-Si alloy (JIS6000 alloy) are optimal. The method for producing the base aluminum alloy material itself is not particularly limited,
The required final material thickness may be obtained through ordinary manufacturing processes such as casting, heating, hot pressing, cold pressing, and annealing.

[0024]

The chemical composition of the aluminum alloy used in the present invention is shown in Table 1. Hereinafter, examples of the present invention will be described. A6009 alloy (Al-Mg-Si based) and A5
182 alloy (Al-Mg) rolled plate (1 mm x 300
mm × 300 mm). Rolled plates of the above A6009 alloy and A5182 alloy were subjected to alkaline degreasing (FC-L
4460: manufactured by Nippon Parkerizing; 43 ° C x 2mi
n, pH = 10.5), washed with water, immersed in a suspension of the particles of the metal inorganic compound shown in Table 1 mixed with pure water at room temperature, rubbed with nylon bran, and washed with water And dried. The particle diameter and particle coverage of the inorganic compound were mainly measured using EPMA, and SIMS was used for particles smaller than 0.1 μm which could not be measured by EPMA.

Subsequently, the aluminum alloy plate to which the above-mentioned inorganic compound was attached was treated with Zn ions: 0.1 to 10 g / l, P
O ₄ ions; 1.0~40g / l, NO ₃ ions; 0.
1 to 10 g / l and free fluorine of 10 to 50
0.1 to 3 g / l of nickel ions and 0.1 to 2 g / manganese ions in an aqueous solution containing 0 ppm
1, 0.1 to 2 g / l of cobalt ion, 0.1 to 1 g / l of iron ion, 0.1 to 1 g / l of nitrite ion,
Inorganic peroxide and / or hydrogen peroxide in an amount of 0.01 to 1 g /
1 was immersed in an aqueous solution at room temperature to 70 ° C. to which an aluminum alloy-treated plate was appropriately added to prepare an aluminum alloy treated plate. The treated plates were dissolved in concentrated nitric acid to dissolve the formed film, and the elements were quantified by atomic absorption analysis. As is clear from Table 1, all of the examples of the present invention were within the scope of the present invention.

A plate of A6009 alloy and A5182 alloy (1 mm × 70 mm × 15
0 mm) and the untreated plate, zinc phosphate treatment (including alkali degreasing and surface conditioning) as a film conversion treatment similar to that of panel materials for automobiles, and cationic electrodeposition coating (film thickness: 20 mm).
μm), an intermediate coating (film thickness 35 μm) and a top coating (film thickness 35 μm). Regarding the coating chemical conversion property, the surface of the zinc phosphate coating formed on each plate after the zinc phosphate treatment was observed with a scanning electron microscope to examine the state of deposition. The evaluation was evaluated as follows: ：: crystal precipitation on the entire surface, Δ: partial material surface, ×: material surface 50% or more. Table 1 shows the evaluation results.

[0027]

[Table 1]

Adhesion after coating: A sample coated with a top coat was immersed in distilled water at 40 ° C. for 10 days, and then N was immediately applied to the coating film.
Cuts were made with a T-cutter so that 100 squares of 1 mm square were formed, and the remaining state of the squares after tape peeling was observed. In the evaluation, ○: no cross-cut peeling, Δ: cross-cut peel area less than 5%, x: cross-cut peel area 5% or more.

The workability of A6009 alloy and A5
A lubricating oil was applied to a test piece having a length of 200 mm and a width of 125 to 140 mm using a 100 mm ball-overhang tool on a 182 alloy-treated plate, and then formed at a molding speed of 10 m.
The molded body was molded at 10 m / min and 10 tons of BHF, and the break molding height (LDH ₀ ) was obtained to evaluate the workability. Evaluation: ○: L
The value of DH ₀ was improved by 30% or more than the untreated material, Δ: improved by 15% or more than the untreated material, and X: equivalent to or less than the untreated material. As is clear from Table 1, the results of the examples of the present invention were all excellent in film conversion treatment, adhesion after coating, and workability.

[0030]

The aluminum alloy plate of the present invention can solve the problem of corrosion resistance after painting which has been a problem in the past.
In applications such as automobiles, it has excellent properties in film chemical conversion and workability. Therefore, the use of the aluminum alloy sheet is greatly expanded, and it can be said that the invention is of an extremely high industrial value.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kazumi Nishimura 20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel Corporation Technology Development Division (72) Inventor Toshiaki Kobayashi 1-2-1 Kinshi, Sumida-ku, Tokyo No. Sky Aluminum Co., Ltd. (72) Inventor Masahiro Kurata 1-2-1 Kinshi, Sumida-ku, Tokyo Sky Aluminum Co., Ltd. F term (reference) 4F100 AA00B AA00C AA03B AA03C AA04A AA04B AA04C AA04H AA08B AA08C AA18A A17B AA17A AA18C AA18H AA21B AA21C AA21H AA23B AA23C AA23H AA24B AA24C AA24H AA25B AA25C AA25H AB09A AB09H AB10A AB11A AB11H AB31A BA02 BA03 BA10A BA10B BA10C BA13 DE01B DE01C EH462 EJ262 EJ682 EJ862 GB32 GB48 JA20B JA20C JK06 JL01 YY00B YY00C 4K026 AA09 AA22 BA04 BA08 BA12 BB06 BB09 BB10 CA16 CA18 CA23 CA27 CA28 CA32 CA35 CA36 CA37 CA41 DA01 EA08

Claims (3)

[Claims] 1. An inorganic compound particle having a particle diameter of 0.001 to 5 μm is coated on one or both surfaces of an arbitrary surface.
Measured in μm ² , a coating area ratio of 20 to 80% was adhered, phosphate: 0.8 to 3.0 g / m ² , fluorine: 5
It is characterized by having a coating containing 0 mg / m ² or less and Na: 25 mg / m ² or less and having a weight ratio of zinc to phosphorus (zinc / phosphorus) of 2.5 to 4.5. Aluminum alloy treated plate with excellent moldability and adhesion after painting. 2. The inorganic compound includes titanium oxide, nickel oxide, magnesium oxide, tungsten oxide, niobium oxide, aluminum oxide, zinc oxide, cuprous oxide, cupric oxide, ferric oxide, molybdenum oxide, and hydroxide. Claims: It is one or a mixture of two or more selected from magnesium, nickel hydroxide, magnesium carbonate, calcium carbonate, zinc phosphate, magnesium oxalate, barium titanate, calcium silicate, and magnesium hydrogen phosphate. Item 4. An aluminum alloy treated plate excellent in formability and adhesion after painting according to item 1. 3. An inorganic compound particle in an amount of 0.01 to 50% by weight.
The above-mentioned inorganic compound particles are adhered by adhering the suspension containing and rubbing it before it dries,
Then, Zn ion: 0.5~10g / l, PO ₄ ion: 5.0~40g / l, NO ₃ ion: 0.5 to 10
The method for producing an aluminum alloy-treated plate excellent in formability and adhesion after painting according to claim 1 or 2, wherein the plate is treated with an aqueous solution containing 30 to 400 ppm of g / l of free fluorine.