JPS5956559A - Aluminum alloy - Google Patents

Abstract

PURPOSE:To obtain an Al alloy having favorable extrusibility and high mechanical strength and developing a grayish-black color tone, by adding specified percentages of Si, Cu and Mg to Al. CONSTITUTION:An Al alloy billet consisting of 4.4-6.0% Si, 0.12-0.30% Cu and 0.20-0.30% Mg as essential components and the balance Al with inevitable impurities is homogenized at <=about 450 deg.C. It is preheated to about 350-470 deg.C, extruded, aged, and anodically oxidized by a conventional method. A desired colored film having a grayish-black color tone is obtd. The L value of the film depends slightly on the homogenizing temp.

Description

[Detailed description of the invention] Section 60, copper 012~0.30%, magnesium 7um 020~
By using aluminum as an essential component and containing other unavoidable impurities, it has relatively good extrudability, yet has high mechanical strength, and has a grayish-black color. The purpose of the present invention is to provide an aluminum alloy that can be used to color objects.

All+! It has been known for a long time that the anodic oxide film of the wrought material of the -81 series alloy exhibits a gray color, and has been used as a building material. However, for example, the typical naturally colored aluminum alloy, 4043 alloy, has low strength.
It corresponds to a semi-rigid 99% pure aluminum wrought material, and must be thick to be used in building window frames, etc. In addition, in order to improve this 4043 alloy, ■ is added, and the alloy hardened by precipitation of Mg2S1, for example, (i(163-T5
Although it has a comparable strength, it has disadvantages such as poor extrusion properties, a black plate cannot be obtained, and the anodic oxide film has a yellowish tinge.

Moreover, slight differences in the anodizing treatment conditions are sensitively reflected in the color tone of the film, and there are also drawbacks such as the tendency to cause color unevenness.

The present invention eliminates the two drawbacks, for example, 60
We have developed an aluminum alloy that has mechanical strength greater than 63 alloy TsiJ, has excellent extrudability, and can produce the desired gray-black color tone with good reproducibility. A certain O Hereinafter, the aluminum alloy according to the present invention will be explained.

In general, the particles in A6-Si naturally colored alloys do not change during anodizing treatment, but immediately migrate into the film and impart color to the film depending on the particle shape and distribution density. In the present invention, in addition to including outputs exceeding 4.4 and below 6.0, the mountain is 012 to 0.30, and the threshold is 02.
0 to 0.3 (including 1).

The fin 7 made of such an alloy composition was heated at 450°C.
After homogenization treatment at a temperature of 350-470'
By preheating and extruding at a temperature of A film is obtained. This alloy composition has an excellent mechanical strength of 6 (comparable to 1G3T54g), and also exhibits excellent extrudability, with a beautiful finish and a good surface condition. be.

In other words, when the content of Sl is low, the desired gray-black color cannot be obtained unless the thick anodic oxide film is chemically formed.Furthermore, there is a disadvantage that the colored film may take on a yellowish tinge. However, if the content of smut is too high, roughness will occur and extrudability will be significantly reduced, and a large amount of smut will be generated during pre-treatment for surface treatment, making it difficult to remove. The content of Sl exceeds 44% and is 0.
It is desirable to have a coefficient of 0 or less, and if it is less than (4) or 2, the strength improvement will be unsatisfactory, and if it exceeds 030, the film formation efficiency will decrease and it will not be possible to obtain the desired color tone. 11, the content of (branch) is 012 to 0.3
By setting it to 0%, not only the strength is improved, but also the extrudability is excellent, and the desired color tone can be obtained. Even one step does not contribute much to hardening, and 0
．． If it exceeds 30%, not only will the productivity decrease, but the colored film will become yellowish, making it impossible to obtain a beautiful grayish-black color. ~0
It has been found that by setting the content to 30%, mechanical strength and extrudability can be balanced and excellent, and a desired color tone can be obtained.

If homogenization is carried out at a temperature exceeding 450°C, there is a risk that the final product will turn pale gray and yellowish. During the process, depending on the temperature of this homogenization process,
The homogenization temperature! L value is about 42 at month 50”
When the homogenization temperature is about 300'Cf L value or about 28, it is possible to produce an anodized film having a gray-black or plate-making black tone. In addition, by setting the extrusion temperature to 350 to 47 (Vis 0), extrusion properties are good, brownish unevenness is less likely to occur, and the surface condition is good, such as no microcracks occurring at the cavity edges. can be made.

Specific examples will be described below.

Example M-55 Section 5i-0, 25 Section (Support)-025 Section 1 ton A billet consisting of other inevitable impurities was heated at 300 to 450°C.
Homogenization treatment for 12 hours at
50°C, 470°C and 470'C respectively
The solid material and the follower were extruded at 50°C, 450°C and 1430°C. After aging at 180°C for 6 hours, approximately 20μ
0, which has been chemically converted into a film of m, has its surface state t',
The mechanical strength was comparable to that of the 61) 63 alloy T5 material, and the desired color tone ranging from gray-black to plate-making black could be obtained depending on the homogeneous housing temperature. In the drawings, the characteristics shown by the solid line are those of this example, and the numbers indicate the temperature at 1 hour during the homogenization process.

Comparative Examples 1 to 3 M - 5,5% 5i - 0,15% Billet consisting of other inevitable impurities, AL - 5,5 article $ - 0,15 article -
7)
, M4.0%si--0.25% and pyreno(.) consisting of 0.25% and other unavoidable impurities was carried out in the same manner as in the previous example.

Characteristics of these compositions are shown by one-dot to three-dot chain lines in the drawings. Note that the numbers indicate the temperature during the homogenization treatment.

As can be seen from these results, by controlling the homogenization treatment conditions, the alloy composition according to the present invention can produce a color density of gray-black or plate-making black. A product with a dark gray tone can be obtained independently of the thickness, and its mechanical strength is as good as that of 6063 Alloy T alloy. It also has excellent extrudability, and has excellent productivity and high performance. Since it is strong, it is used for building materials such as Sanonri.

As mentioned above, the aluminum alloy according to the present invention contains 44%
Si over 60 or less, 0. ]22% above 030%
The following Cu, 0.20% or more and 0.30% or less, are essential components, and the anode contains fine inevitable impurities and the remainder is A6, so the anode is chemically formed according to the homogenization temperature. The oxide film has a flashing color regardless of its thickness, and has high mechanical strength, for example, 60
It has excellent mechanical properties comparable to those of Alloy 63 T alloy, and has excellent extrudability, resulting in good productivity, making it suitable for building materials such as Sanon. have

[Brief explanation of drawings]

The drawing is a graph showing the properties of yield strength and L value of an aluminum alloy.

Claims (1)

[Claims] 44 or more" U6.0% or less si, 0.12% or more and 0.30 chi or less (g), 020% or more 0.30%
An aluminum alloy that contains the following essential ingredients, contains other inevitable impurities, and has the remainder A6.