JPH08260164A - Plated aluminum sheet excellent in powdering resistance - Google Patents

Abstract

PURPOSE: To obtain a plated aluminum sheet excellent in powdering resistance by providing an anodized film exhibiting a specified shape by X-ray photoelectron spectroscopy(XPS) between the surface of the aluminum sheet and the plating. CONSTITUTION: An aluminum sheet is electrochemically anodized to form an anodized film on the surface, and a plating is applied thereon. When the anodized film is subjected to XPS measurement, the spectral peak on an Al2p orbit measured at a binding energy of 74-78eV disappears in the sputtering time of 10-1000min. A plated aluminum sheet excellent in sputtering resistance when press-formed is obtained in this way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plated aluminum plate having excellent powdering resistance, and more particularly to a plated aluminum plate applicable to various applications such as an automotive aluminum plate.

[0002]

2. Description of the Related Art In recent years, with increasing awareness of environmental issues, serious consideration has been given to weight reduction for the purpose of improving fuel efficiency of automobiles. One way to do this is to use aluminum plates for body panels. However, it is rare to manufacture the entire body of an automobile from an aluminum plate, and in general, a part of the body is replaced with a steel plate from an aluminum plate. Here, in automobile production lines, aluminum sheets are mostly used in automobile production lines established with current steel sheets, and therefore their material properties are required to be equivalent to or better than those of steel sheets. It is important that it can be applied to the existing automobile manufacturing line itself.

Some attempts have been made to make the properties of an aluminum plate required for assembling an automobile body close to those of a steel plate with respect to zinc phosphate treatment as a pretreatment for coating. For example, JP-A-61-157693, JP-A-4-17677, JP-A-4-17678, JP-A-4-17679, and JP-A-4-1768.
In JP-A-0, a method of galvanizing an aluminum plate is proposed as a method of improving the zinc phosphate treatment property of the aluminum plate. However, these are all aimed at improving the zinc phosphate property, and no one aiming at improving the powdering resistance as in the present invention has been proposed so far.

[0004]

In order to use an aluminum plate in an existing automobile manufacturing line, it is required that its material characteristics be equal to or higher than that of a steel plate. However, when the aluminum plate is plated, a phenomenon called powdering occurs in which the plating is separated during press molding.
When powdering occurs, the peeled plating causes pressure scratches on the aluminum plate, and this powdering must be prevented. Therefore, the present invention provides a plated aluminum plate that solves the above problems, that is, a plated aluminum plate having excellent powdering resistance.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted diligent research on the development of a plated aluminum plate which is low in cost and excellent in powdering resistance in order to solve these problems. The present invention has been made by discovering that a plated aluminum plate having excellent powdering resistance can be obtained by preparing a specific anodized film and plating it. That is, the gist of the present invention is a plated aluminum plate having an anodized film between the surface of the aluminum plate and the plating, and the binding energy when the anodized film is measured by XPS (X-ray photoelectron spectroscopy). Al2p measured at 78 eV
A plated aluminum plate having excellent powdering resistance, in which the orbital spectral peak disappears within a sputtering time of 10 to 1000 minutes. The aluminum plate and the aluminum alloy plate are collectively referred to as an aluminum plate.

[0006]

The present invention will be described in detail below. The plated aluminum plate having excellent powdering resistance of the present invention can be obtained by applying a specific anodizing coating on the surface of the aluminum plate. Since it is difficult to identify the morphology of the anodized film from the current analysis technology, when the anodized film is measured by XPS (X-ray photoelectron spectroscopy), the binding energy of the Al2p orbital measured at a binding energy of 74 to 78 eV Sputtering time until the spectrum peak disappears,
The film characteristics are characterized by defining it for 10 to 1000 minutes. The reason why the sputtering time is set to 10 minutes or more is that the powdering resistance is poor if the sputtering time is less than 10 minutes.
The reason why it is set to not more than 1000 minutes is that if it exceeds 1000 minutes, a thick oxide film is formed, workability is poor, and cost is high. It is preferably 10 minutes or more and 500 minutes or less. The conditions for measuring the anodized film by XPS do not have to be specified in particular, but an example of the measurement conditions that are usually performed is AlK under the conditions of a radiation source output of 400 W and a path energy of 50 eV.
It is measured using alpha rays. The XPS measuring device may be any commercially available product.

The anodized film is formed by performing an electrochemical anodic reaction on the surface of the aluminum plate. The anodized film may be produced by any method as long as a film having a predetermined film thickness is formed, and the following can be typically mentioned. (1) The aluminum plate is subjected to anode electrolysis in an acid bath such as a sulfuric acid bath, a phosphoric acid bath, an oxalic acid bath, and a chromic acid bath. (2) The aluminum plate and an electrochemically noble metal are brought into contact with each other in an acid bath such as a sulfuric acid bath, a phosphoric acid bath, an oxalic acid bath and a chromic acid bath. (3) The aluminum plate is immersed in an acid bath such as a sulfuric acid bath, a phosphoric acid bath, an oxalic acid bath, and a chromic acid bath containing an oxidizing agent.

That is, the electrochemical anodization is
It broadly includes a process of forcibly energizing from the outside, a process of energizing by utilizing a potential difference between metals, a process of utilizing redox reaction of ions in a solution and the surface of an aluminum plate, and the like. When this anodized film is measured by XPS (X-ray photoelectron spectroscopy), the energy is 74 to 78 eV.
The condition that the sputter time until the spectral peak of the Al2p orbit measured in 1) disappears for 10 minutes or more is
The amount of electricity applied when electrochemically anodizing is 1C
/ Dm ² or more. In the present invention, electroplating is not particularly limited, and any method may be used as long as it is a method of electrolytically depositing metal ions dissolved in an aqueous solution. In particular, when preparing a plated aluminum plate for use as an automobile outer plate, it is desirable to use zinc-based alloy plating in consideration of the fact that zinc phosphate treatment is widely used in the current automobile manufacturing line. .

[0009]

EXAMPLES The features of the present invention will be specifically described below with reference to examples. Example 1 First, a rolled plate of JIS 5182-O material was prepared as a raw material, and an anode treatment film as shown in Table 1 and Table 2 was electrochemically formed on the plate, and then electroplating was performed. The electroplating was obtained by performing electroplating using a plating bath containing each metal ion. The evaluation test was performed using a cylindrical molding test. The test conditions are shown below. Specimen size: Thickness 1.0 mm Diameter 140 mm Punch diameter: 78 mm Die diameter: 80 mm Drawing ratio: 1.8 Wrinkle holding pressure BHF: 5 ton Drawing depth: 40 mm Drawing speed: 300 mm / sec Evaluation of powdering property: Tape peeling method According to Evaluation,
◯: Almost no peeling is observed, Δ: Peeling is 1 on the tape
Adhesion at an area ratio of 0 to 50%, x: 50% peeling on the tape
Adhesion was carried out in three stages at the above area ratio. The results are as shown in Tables 1 and 2, and the materials of the present invention have improved powdering resistance.

[0010]

[Table 1]

[0011]

[Table 2]

Example 2 First, a rolled aluminum alloy plate shown in Table 3 was prepared as a raw material, and an anodized coating as shown in Table 3 was electrochemically formed on the rolled aluminum alloy plate, followed by electroplating. The electroplating was obtained by performing electroplating using a plating bath containing each metal ion. The evaluation test was performed under the same conditions as in Example 1. The results are shown in Table 3,
The materials of the present invention all have improved powdering resistance.

[0013]

[Table 3]

Example 3 First, a rolled sheet of JIS5182-O material was prepared as a raw material, and an anodic treatment coating as shown in Table 4 was electrochemically formed on the rolled sheet, followed by Zn- (10%) Fe electroplating. I went. The electroplating was obtained by performing electroplating using a sulfuric acid plating bath containing Zn ions and Fe ions. The evaluation test was performed under the same conditions as in Example 1. The results are shown in Table 4, and all the inventive materials have improved powdering resistance.

[0015]

[Table 4]

[0016]

According to the present invention, an anodizing coating is applied between the surface of an aluminum plate and the plating, and the coating is X-coated.
By limiting the sputtering time until the spectrum peak of the Al2p orbit disappears in PS measurement, a plated aluminum plate having excellent powdering resistance can be manufactured. Thereby, when the customer performs press molding,
The separation of the plating does not occur and the device yield can be improved.

Claims (1)

[Claims] 1. Between the surface of the aluminum plate and the plating,
A plated aluminum plate having an anodized coating, wherein the Al2p orbital spectral peak measured at a binding energy of 74 to 78 eV when the anodized coating is measured by XPS (X-ray photoelectron spectroscopy) is 10 to 100.
A plated aluminum plate with excellent powdering resistance, which disappears within 0 minutes of sputtering time.