JPH0273936A - High rigidity aluminum alloy extrusion material for structural body - Google Patents

Abstract

PURPOSE:To improve the rigidity, strength, weldability, extrudability, etc., of the title material by specifying Si, Mg, Cu and Al. CONSTITUTION:The high rigidity Al alloy extrusion material for a structural body is formed with the compsn. constituted of, by weight, 7.5 to 17% Si, 0.3 to 1% Mg and/or 0.3 to 0.8% Cu, <=1.6% Mg+Cu and the balance Al. The above Al alloy has high rigidity and furthermore has excellent strength, weldability, extrudability, heat treatability or the like.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to highly rigid materials for structures, and more specifically to structural materials for welding that require high rigidity, such as IJ railway vehicles, automobiles, and automobiles. 1-Pie, relating to a highly rigid aluminum structure suitable for bicycle structures.

[Prior Art] In recent years, aluminum materials have come to be used or considered for the structures of railway vehicles, automobiles, automobiles, bicycles, etc.

These aluminum materials include 5000 series, 6000 series, and 7000 series from the viewpoint of strength, weldability, extrusion moldability, etc.
system is often used.

However, in recent years, these vehicles have become faster and faster, and as a result, it has become necessary for their structures to have high rigidity in terms of running performance, comfort, etc.

In such situations, there are some things that cannot be addressed by improving rigidity through shape, so in order to further increase rigidity,
There is a growing demand for improved rigidity of aluminum itself.

Conventional high-rigidity materials include A, +2-Lj gold alloy FRM.
However, these U-materials are difficult to extrude into hollow thin walls, and the manufacturing cost is also high, so they are difficult to use in general structures such as those mentioned above.

[Problems to be Solved by the Invention] The present invention provides a highly rigid aluminum material for bridge bodies that has high rigidity and also satisfies properties such as strength, weldability, extrusion moldability, and heat treatability. be.

[Means for Solving the Problems] The aluminum base metal extrusion material according to the present invention is characterized by containing 7.5 to 17 wt% of Si, and further containing M.
g: 0.3-1.0wt%, Cu03-0.8wt
% fffi or two, and the total amount of Mg and Cu is 16 wt % or less, with the remainder consisting of A° C. and impurities.

[Function] The aluminum alloy for extrusion according to the present invention will be described in detail below.

First, the components and component ratios of the aluminum alloy for extrusion according to the present invention will be explained.

Si: is an essential element for increasing rigidity and adding strength, and in order to make these properties superior to ordinary aluminum alloys, it is necessary to contain 7.5 wt% or more. , and when I is contained in excess of 7wt%, a large amount of primary crystals S] is formed, and
Extrusion into rough shapes becomes difficult. Therefore, the St content is set to 7.5 to 17 wt%.

Mg and Cu are elements that show roughly the same effect and improve mechanical properties through aging, or are elements that improve mechanical properties during extrusion.
It solidly dissolves in the solid solution and increases deformation resistance, reducing extrudability. Therefore, in order to make the mechanical strength equivalent to or higher than that of 6N01, the Mg and Cu content must be 0.3wt when contained alone.
% or more, and when contained alone, Mg, C
The upper limit of u is determined by extrudability, but Mg is 1.0wt.
%, Cu is set at 0.8 wt%, and if the total content exceeds 1.6 wt%, extrusion into a complex shape having a hollow part becomes impossible. Therefore, the Mg content is 03 to 1.0 wt%, and the Cu content is 03 to 08 wt%.
%, and the total amount of Mg and Cu is 1.6 wt% or less. Note that Mg precipitates as Mg2Si and is difficult to form a solid solution in the matrix during extrusion, so it has a smaller effect on increasing deformation resistance than Cu, so even if the upper limit content of Mg is higher than the upper limit content of Cu. Differences in content often occur.

In addition to the above-mentioned components, in order to refine the ingot structure and stabilize the mechanical properties, Ti:0.
001 to 0.05 wt% may be contained.

In addition, in order to improve the mechanical properties by making the structure of the extruded material fibrous, Cr: 0.05 to 0.3 wt% Zr: 0
105 to 025 wt% Mn: One or more im selected from 0.3 to 0.7 wt% may be contained.

Usually, when an ingot is melted, Na, Sr, and P are added to make the Si fine, and the ingot is homogenized and Si spheroidized at a temperature of 450° C. or higher.

[Example] Next, an example of the aluminum alloy extruded material according to the present invention will be described.

Aluminum alloys having the components and proportions shown in Table 1 were melted by a conventional method to produce ingots of 245φ and 155φ.

This ingot was extruded, and its extrudability, strength, weldability, and rigidity were compared and evaluated with the 6NO1 alloy, which is widely used in conventional railway vehicles, using the methods shown below.

In Table 2, extrudability is determined by extruding a 245φ ingot into a hollow member with a cross-sectional shape shown in Figure 1 at an extrusion speed of 3 m/mi.
◎ for those that do not crack at 3 m/min or more, 012 m/m for those that crack at 3 m/min but not at 2 m/min
In the case of "in", those in which cracks occurred were evaluated as "×".

When examining properties such as strength, weldability, and rigidity, a 155φ ingot was extruded into a cross-sectional shape of 4txlOOw, fan air cooling was performed immediately after extrusion, and a predetermined heat treatment was performed to obtain a test material. Note that butt welding was performed for the welding materials, and two types of welding wires, 40435356, were used.

The results are shown in Table 2.

The following is clear from this Table 2.

No. I, which is an aluminum alloy extruded material according to the present invention
~No, 3. No, 5. No. 6 is 2 m/m i
It can be extruded at a speed of n or more, and No. 4 is 1
It can be extruded at an extrusion speed of m/min, and No.
Nos. 1 to 6 have high rigidity, and the strength is also equivalent to 6N01. Furthermore, since it has good extrudability, it is suitable as a structural material for railway vehicles, automobiles, motorcycles, bicycles, etc.

Comparative alloy No. 7. In No. 8, cracks occurred at an extrusion speed of 1 m/min, and the material could not be used practically as an extruded material.

[Effects of the Invention] As explained above, the aluminum alloy extruded material according to the present invention has the above-mentioned structure, so it has excellent extrudability, high rigidity, good weldability, and mechanical properties. It also has the effect of having excellent developmental properties. Therefore, it is suitable as a structural material that requires rigidity.

Table 1 Table 2

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an extruded material having a complex shape and having a hollow portion that can be extruded by the aluminum alloy extruded material according to the present invention. *No extra portion

Claims (1)

[Claims] Contains Si: 7.5 to 17 wt%, and further contains Mg: 0.
3 to 1.0 wt%, Cu: 0.3 to 0.8 wt%, and a total of 1.0 wt% of Mg and Cu.
A high-rigidity aluminum alloy extruded material for a structure, characterized in that the content is 6 wt% or less, and the remainder consists of Al and impurities.