JPH05320807A - High strength Al-Mg-Si alloy - Google Patents

Abstract

(57) [Summary] [Purpose] Has strength superior to JIS 6061 alloy,
In addition, an Al-Mg-Si-based alloy that is equal to or more than the 6061 alloy in terms of toughness, corrosion resistance, etc. is also provided. [Structure] Mg: 1.1 to 1.5 wt%, Si: 0.7 to
1.4 wt%, Cu: 0.2-0.6 wt%, Cr: 0.05-0.2 wt%, Mn: 0.05-0.
It contains at least either of 2 wt% and the balance is aluminum and inevitable impurities.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-strength aluminum alloy, particularly Al-Mg-Si based alloy, which is used for automobile parts materials and various other purposes.

[0002]

2. Description of the Related Art Since aluminum materials have advantages such as lightness, they have come to be widely used in automobile parts and the like where there is a strong demand for weight reduction. For example,
Aluminum extruded materials and the like have come to be used also in automobile foot parts and the like which are made of various forged materials.

As an aluminum alloy used for the above-mentioned automobile parts and the like, JIS6061Al, which is an Al-Mg-Si type alloy excellent in extrudability and the like, has hitherto been used.
Although an alloy was generally used, such an aluminum alloy is not sufficient in terms of strength, and the strength is further improved.
An l-Mg-Si based alloy has been desired.

The present invention has been made in view of the above circumstances, and is Al-Mg that has strength superior to JIS 6061 alloy and is equal to or higher than 6061 alloy in terms of toughness, corrosion resistance and the like. -To provide a Si-based alloy.

[0005]

In order to achieve the above object, the present invention provides Mg: 1.1 to 1.5 wt%, Si: 0.
7-1.4 wt%, Cu: 0.2-0.6 wt%,
Further, Cr: 0.05 to 0.2 wt%, Mn: 0.05 to
The gist is a high-strength Al-Mg-Si alloy containing at least one of 0.2 wt% and the balance aluminum and inevitable impurities.

In the above, Mg (magnesium), S
i (silicon) is an element that produces Mg ₂ Si in the alloy and strengthens the precipitation by strengthening the precipitation. However, if Mg is less than 1.1 wt% or Si is less than 0.7 wt%, the above effect is poor and desired high strength cannot be realized. on the other hand,
If Mg exceeds 1.5 wt% or Si exceeds 1.4 wt%, extrudability and the like are impaired and hardenability is deteriorated, and on the contrary, sufficient strength cannot be obtained. Therefore, Mg should be contained in the range of 1.1 to 1.5 wt% and Si should be contained in the range of 0.7 to 1.4 wt%. Particularly preferable content ranges are: Mg: 1.1 to 1.3 wt%, Si: 0.8 to 1.2 wt%
Is.

Cu (copper) is also an element effective for improving the alloy strength by precipitation strengthening and improving the elongation. However, if it is less than 0.2 wt%, the effect of improving precipitation strengthening and elongation is poor. On the other hand, if it exceeds 0.6 wt%, extrudability,
It causes deterioration of corrosion resistance. Therefore, Cu is 0.2-0.6 wt
Must be contained in the range of%. The particularly preferable content range of Cu is 0.5 to 0.6 wt%.

[0008] Cr (chromium) and Mn (manganese) are elements that are precipitated as fine intermetallic compounds during homogenization treatment and refine recrystallized grains to improve strength and elongation. In terms of such effects, both Cr and Mn can be evaluated as equivalents. Therefore, it is sufficient if at least one of them is contained, but both are 0.05
If it is less than wt%, the above effect is poor, and conversely, if either of them exceeds 0.2 wt%, a coarse intermetallic compound crystallizes and hinders formability. Therefore, at least one of Cr and Mn must be contained in the range of 0.05 to 0.2 wt%. Particularly preferable content range is Cr: 0.08 to
0.14 wt% and Mn: 0.08 to 0.14 wt%.

In addition to the above elements, Ti: 0.
A content of 005 to 0.2 wt% is allowed. Ti is an element that makes crystal grains fine during casting and contributes to the improvement of the strength of the alloy, but its effect is poor at 0.005 wt%. On the other hand, if the content exceeds 0.2 wt%, not only the effect is saturated, but also a coarse intermetallic compound crystallizes and hinders the formability. A particularly preferable range when Ti is contained is 0.02.
~ 0.05 wt%.

The aluminum alloy according to the present invention is preferably manufactured by extruding a homogenized billet into an extruded material, and then sequentially performing solution treatment, quenching and aging treatment. Conditions such as homogenization treatment, solution treatment, quenching, and aging treatment may be set to the same conditions as in the case of the conventional 6061 aluminum alloy.

[0011]

EXAMPLES Aluminum alloy billets having various compositions shown in Table 1 below were homogenized. Homogenization process is No2,
It was carried out under the conditions of 530 ° C. × 12 hours for 5, 7, 9 and 11 and 560 ° C. × 12 hours for the others.

Next, after each billet was extruded at 480 ° C., solution treatment at 540 ° C. for 1 hour, quenching (water cooling), and artificial aging treatment at 170 ° C. for 11 hours were sequentially performed.

A tensile test was carried out on each of the extruded materials thus obtained, and their mechanical properties were investigated.
(Compound cycle corrosion test) was performed to evaluate the corrosion resistance. The results are shown in Table 1.

[0014]

[Table 1] As is clear from the results of Table 1, N which is a product of the present invention
It is understood that all of o1 to 7 have excellent strength as compared with No14 which is a conventional product, have ductility and toughness equal to or higher than the same, and have the same corrosion resistance.

Further, as can be seen from the comparative products Nos. 8 and 9, when the Cu content exceeds 0.6 wt%, the corrosion resistance decreases, and when it is less than 0.2 wt%, the effect of improving the strength is insufficient.

Further, as can be seen from the comparative products Nos. 10 and 11, if the Si content exceeds 1.4 wt%, the strength rather decreases, and if it is less than 0.7 wt%, the strength improving effect itself is insufficient.

Further, as can be seen from the comparative product No. 12,
If the Mg content is less than 1.1 wt%, the strength improving effect is insufficient. Also, as can be seen from comparative product No. 13,
When both r and Mn are less than 0.05 wt%, the strength is poor.

[0018]

According to the present invention, Mg: 1.1 to 1.5 wt.
%, Si: 0.7 to 1.4 wt%, Cu: 0.2 to 0.6
wt%, Cr: 0.05-0.2 wt%, M
n: At least one of 0.05 to 0.2 wt% is contained, and the balance is composed of aluminum and unavoidable impurities. Therefore, it is equal to or more than JIS6061Al alloy conventionally used for automobile parts. While possessing the toughness and corrosion resistance described above, 606
High-strength Al-Mg-S with strength superior to 1 alloy
It can be an i-based alloy. Therefore, by using this aluminum alloy as a material for automobile parts and the like, it is possible to further reduce the weight and size of the automobile and the like.

Front page continuation (72) Inventor Hitoshi Kazama, 1-4-1 Chuo, Wako-shi, Saitama, Ltd., Honda R & D Co., Ltd. (72) Inventor, Kotonori Sugimoto, 6-224, Kaiyamacho, Sakai City, Osaka Prefecture Showa Aluminum Shares In-company (72) Koichiro Fukui, 6-224, Kaiyama-cho, Sakai-shi, Osaka Prefecture, Showa Aluminum Co., Ltd. (72) In-house, Tsunemasa Miura, 6-224, Kaiyama-cho, Sakai-shi, Osaka Prefecture, Showa Aluminum Co., Ltd. (72 ) Inventor Ichiro Iwai 6-224, Kaiyamacho, Sakai City, Osaka Prefecture Showa Aluminum Co., Ltd. (72) Inventor Hiroyuki Eda 6-224, Kaiyamacho, Sakai City, Osaka Prefecture Showa Aluminum Co., Ltd. (72) Inventor Maehara Hisashi, Showa Aluminum Co., Ltd., 6-224 Kaiyamacho, Sakai City, Osaka Prefecture

Claims (1)

[Claims] 1. Mg: 1.1-1.5 wt%, Si: 0.
7-1.4 wt%, Cu: 0.2-0.6 wt%,
Further, Cr: 0.05 to 0.2 wt%, Mn: 0.05 to
A high-strength Al-Mg-Si alloy containing at least 0.2 wt% of aluminum and the balance aluminum and inevitable impurities.