JPH07155828A - Hollow Rice for Extrusion of Zinc-Containing Aluminum Alloy - Google Patents

Abstract

(57) [Summary] [Object] To provide a zinc-containing aluminum alloy extruding holloidice capable of preventing cracking and extending the life of the die without significantly changing the structure. [Structure] The left and right bridges 19a and 19b are members that connect the mandrel member 13 and the outer cylinder member 11. The bridges 19a and 19b are provided with a convex portion 23 that smoothly protrudes toward the mandrel member 13, and the surface of the convex portion 23 is a main part of this embodiment (shown by a mesh in the figure). ) A coating film 25 is formed. This film 25
Is 53Ni-18.0Cr-3.1Co-18.5Fe-0.
A 3 mm-thick layer made of a Ni alloy having a composition of 18 Si. The left and right bridges 19a and 19b are formed by welding overlay.
It is firmly joined to the convex portion 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zinc-containing aluminum alloy extruding hollow blade for extruding a hollow aluminum alloy profile.

[0002]

2. Description of the Related Art Conventionally, when an aluminum alloy hollow material is extruded, a hollow chair P1 as shown in FIG. 5 is used. This hollow chair P1 is a porthole die which is a combination of a male die P2 (shown by a solid line) forming a hollow portion of a profile and a female die P3 (shown by a chain double-dashed line) forming an outer peripheral portion of the profile.

At the center of the male die P2 of the die P1, a mandrel P5 is provided so as to project from the mandrel support portion P4. On the other hand, the female die P3 is formed with a forming hole P6 that forms the outer peripheral portion of the profile. Therefore, by combining the two, a molding gap P7 is formed between the tip of the mandrel P5 and the molding hole P6, and the extruded material is passed through this gap P7 to mold the hollow shape member.

[0004]

However, in the case of producing an extruded material of an aluminum alloy, in general, the life (production weight) of the die P1 is 10 tons or more / die, whereas, for example, (zinc Contained aluminum alloy)
For extrusion of 7000 series Al-Zn-Mg alloy, 1 ton /
Most of the dies are less than the die P1, and the productivity is extremely low in terms of tool cost and the like.

The reason why the die P1 has a short life as described above is that a part of the die P1 is cracked during the work.
The place where this crack occurs is usually the portion of the bridge P8 shown in FIG. 5, that is, the base portion of the mandrel P5 which is the mandrel support portion P4 (a portion in the figure). This is because the portion a in the figure is a portion where stress concentration is likely to occur due to the extrusion load due to the structure of the die P1.

Therefore, in recent years, attempts have been made to reduce the stress generated at the target portion by making the structure of the die P1 fine. However, since the structure is changed, the structure becomes more complicated than that of the general die P1, and there is a problem in processing difficulty and assembling accuracy. ,Also,
Since stress concentration occurs at another location due to the structural change, only the crack location changes and it is not a sufficient countermeasure against cracking.

The present invention has been made to solve the above problems, and it is possible to prevent cracking and extend the life of the die without changing the structure so much. The purpose is to provide.

[0008]

In order to achieve the above object, the invention of claim 1 is a male die having a mandrel forming a hollow portion of a profile and a female die having a forming hole forming an outer peripheral portion of the profile. A zinc-containing aluminum alloy extruding horoidice characterized by being formed by bonding a coating having zinc embrittlement resistance to the base of a male mandrel.

Further, the invention of claim 2 is characterized in that the root portion on which the film is formed is the surface of a bridge supporting the mandrel, and the gallium for extruding zinc-containing aluminum alloy according to claim 1 is summarized. And
Here, as the coating having zinc embrittlement resistance, for example, 5
3Ni-18.0Cr-3.1Co-18.5Fe-0.18S
i composition, 53Ni-17.5Cr-18.5Co-4M
Ni alloys with a composition of o are mentioned, but especially the Ni component is 4
It is preferably 0% or more. In addition to Ni alloy,
Molybdenum and Mo alloys containing molybdenum as the main component can also be adopted, and further, Co alloy containing Co as the main component, Cr,
An alloy with Ta, Ti, Nb, W or the like can also be adopted.

The thickness of the coating varies depending on the material of the coating, but a thickness within the range of 10 mm or less can be adopted. Furthermore, since it is necessary that this coating has a strong bondability that does not easily peel off even if a large stress is applied during extrusion, the method of forming this coating includes, for example, overlay welding, thermal spraying, chemical coating. Various methods such as the above can be adopted.

[0011]

The cracks that occur during extrusion of 7000 series Al-Zn-Mg alloys occur without large plastic deformation.
This crack is caused by Zn in the extruded aluminum alloy.
Is considered to be zinc embrittlement cracking caused by diffusion into the grain boundaries of the steel material of the die. Therefore, as a measure to prevent this cracking, it is conceivable not to directly contact the stress concentration points of the aluminum alloy and the steel material, but in that case, without causing zinc embrittlement on the steel surface and extruding. It is necessary to provide a strong coating that withstands the material flow inside.

The present invention has been obtained from such research, and by forming a coating that is less prone to zinc embrittlement at the base of the mandrel, cracks are prevented and the life of the die is reduced. Can be extended.

[0013]

Preferred embodiments of the present invention will be described below with reference to the drawings in order to further clarify the constitution and effects of the present invention described above. FIG. 1 shows a zinc-containing aluminum alloy extruding holo-dice of Example 1 (hereinafter simply referred to as an extruding holo-dice), (a) is a plan view thereof, (b) is its AA cross-sectional view, and (c) is thereof. It is a BB sectional view.

(Embodiment 1) As shown in FIG. 1, an extrusion hollow rice 1 of this embodiment comprises a female die 3 (shown by a chain double-dashed line) and a male die 5 (shown by a solid line). Through the gap (orifice) 7 formed by the molds 3 and 5, the shape member is extruded into a rectangular tubular shape (see FIG. 3A). Of these, the female die 3 has a molding hole 9 which forms the outer peripheral portion of the shape member at the axial center thereof, while the male die 5 has an outer cylinder member 11, a mandrel member 13, and a mandrel support member 15. The plurality of members are integrally formed.

The outer cylinder member 11 of the male die 5 is provided with an opening portion inside thereof, and the mandrel support member 15 is arranged so as to divide the opening portion so as to divide the opening portion. It is divided into left and right ports 17a and 17b. The mandrel support member 15 is a plate-shaped member, and the mandrel member 13 is erected in the central portion 15 thereof.
a and the left and right bridges 19a, 1 of the mandrel member 13
9b and. Of these, the mandrel member 13 is a plate-shaped member having a rectangular cross section, and a bearing portion 21 that forms a slight orifice 7 with the female die 3 is formed at the tip thereof. On the other hand, the left and right bridges 19
Reference characters a and 19b are members that connect the mandrel member 13 and the outer cylinder member 11.

As shown in FIG. 2, each of the bridges 19a and 19b is provided with a convex portion 23 that smoothly protrudes toward the mandrel member 13, and the surface of the convex portion 23 is the same as that of the present embodiment. A coating film 25 (shown by a mesh in the figure), which is a main part, is formed. This coating 25 is 53Ni-18.0C
A layer having a thickness of 3 mm and made of a Ni alloy having a composition of r-3.1Co-18.5Fe-0.18Si, and firmly bonded to the convex portions 23 of the left and right bridges 19a and 19b by weld overlay. There is.

When welding overlay is performed to form such a coating 25, a Ni alloy welding rod having a diameter of, for example, 2 mm is used for the convex portion 23, and the Ni alloy rod is welded by ordinary welding. After melting and bonding, the surface of the coating 25 formed by bonding is ground and polished by a grinder or the like to smooth the surface.

The extrusion holo-dice 1 of the present embodiment having the above-mentioned constitution has a zinc embrittlement resistance due to the coating 25 made of a Ni alloy, and this coating 25 has a bridge 19 structure.
Since it is firmly bonded to a and 19b, there is a remarkable effect that cracking and peeling are unlikely to occur and the life thereof is extremely long.

(Experimental Example 1) Next, an experimental example in which the extrusion (horizontal life) of the present Example was actually extruded and its durability (life) was examined will be described together with Comparative Examples. In this experiment, a die provided with a coating made of the Ni alloy and a conventional die not provided with such a coating were used, and extrusion was performed under the following conditions to examine the state of the die. The results are shown in Table 1 below.

<Experimental conditions> Extruded material: 7N01 (Al-4.5Zn-1.2Mg) Die steel material: SKD61 coated Ni alloy overlay material; 53Ni-18.0Cr-3.1C
o-18.5Fe-0.18Si Extrusion shape: Square tube Extrusion conditions; Billet heating temperature 520 ° C, Extrusion speed 10
m / min

[0021]

[Table 1]

As can be seen from Table 1, the die of this embodiment having the Ni alloy coating formed by the weld overlay has no abnormality even when the extrusion amount reaches 3000 kg, and is extremely durable. It is clear that On the other hand, in the case where the coating film of Comparative Example is not provided, die cracking occurs at an extrusion amount of 500 kg, and there is a problem in durability.

(Second Embodiment) Next, a second embodiment will be described with reference to FIG. 4A and 4B show an extrusion hollow rice of Example 2, in which FIG. 4A is a plan view thereof, and FIG.
D sectional view, (c) is the EE sectional view.

As shown in FIG. 4, the extrusion hollolander 31 of this embodiment comprises a female mold 33 (shown by a chain double-dashed line) and a male mold 35 (shown by a solid line). However, the extrusion is performed in a cylindrical shape (see FIG. 3B). Among them, the female die 33 has a molding hole 37 which forms the outer peripheral portion of the shape member in the axial center portion thereof, while the male die 35 includes the outer cylinder member 39, the mandrel member 41, and the mandrel support member 43. The plurality of members are integrally formed.

The outer cylinder member 39 of the male die 35 is provided with an opening portion inside thereof, and the mandrel support member 43 branched from the center into three directions so as to divide the opening portion.
Are arranged so that the opening part has three ports 4
It is divided into 5a-c. The mandrel support member 4
Reference numeral 3 denotes a member branched in three directions as described above, and includes a central portion 41a on which the mandrel member 41 is erected, and three plate-shaped bridges 47a extending radially from the central portion 41a.
To c.

Of these, the mandrel member 41 is a member having a circular cross section, and a bearing portion 51 which forms a slight gap 49 with the female die 33 is formed at the tip thereof. On the other hand, the three bridges 47a to 47c are shown in FIG.
As shown in FIG. 5, a convex portion 53 similar to that in the first embodiment is formed so as to smoothly project to the mandrel member 41 side, and the surface of the convex portion 53 is a main part of the present embodiment (FIG. Coating 55) is formed.

The coating 55 is 53Ni-17.5Cr-.
3mm thickness made of Ni alloy with 18.5Co-4Mo composition
And is firmly joined to the convex portions 53 of the bridges 47a to 47c by welding overlay. (Experimental Example 2) Next, the same durability experiment as in Experimental Example 1 was conducted using the extrusion holo-dice of this Example.
The experimental conditions are as follows, and the results are shown in Table 2 below.

<Experimental conditions> Extruded material: 7003 (Al-6.0Zn-0.8Mg) Die steel material: SKD61 coating Ni alloy overlay material; 53Ni-17.5Cr-18.5
Co-4Mo extrusion shape: cylindrical extrusion conditions; billet heating temperature 520 ° C, extrusion speed 10
m / min

[0029]

[Table 2]

As can be seen from Table 2, the die of this embodiment having the Ni alloy coating formed by the weld overlay has no abnormality even when the extrusion amount is 5000 kg, and is extremely durable. It is clear that On the other hand, in the case where the coating film of Comparative Example is not provided, the die crack occurs at the extrusion amount of 700 kg, and there is a problem in durability.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments and can be implemented in various modes without departing from the scope of the present invention.

[0032]

As described above in detail, in the zinc-containing aluminum alloy extruding hollow rice of the present invention, a coating having zinc embrittlement resistance is bonded to the surface of the base of the male mandrel, for example, the surface of the bridge. Since it is formed, there is a remarkable effect that the crack can be prevented and the life of the die can be greatly extended without particularly changing the structure.

Therefore, the use of this die has the advantages that the productivity is improved and the manufacturing cost of the extruded material is reduced.

[Brief description of drawings]

FIG. 1 shows an extrusion hollow rice of Example 1,
(A) is the top view, (b) is the AA sectional view,
(C) is the BB sectional drawing.

2A and 2B show a male mold of Example 1, where FIG. 2A is a plan view thereof, and FIG. 2B is a sectional view taken along line CC of FIG.

FIG. 3 is an explanatory diagram showing a shape of an extruded material.

FIG. 4 is a view showing an extrusion holo-dice of Example 2,
(A) is the top view, (b) is the DD sectional view,
(C) is the EE sectional view.

5A and 5B show a conventional die, wherein FIG. 5A is a plan view thereof, and FIG. 5B is a sectional view taken along line F-F thereof.

[Explanation of symbols]

1, 31 ... Extruding Hollow Rice 3, 33 ... Female 5,35 ... Male 13, 41 ... Mandrel Member 15, 43 ... Mandrel Supporting Member 19a, 19b, 47a, 47b, 47c ... Bridge 25, 53 ... Coating

Claims (2)

[Claims] 1. A male mandrel for a zinc-containing aluminum alloy extruding holo-dice, which comprises a combination of a male mold having a mandrel forming a hollow portion of a shape member and a female mold having a forming hole forming an outer peripheral portion of the shape member. A zinc-containing aluminum alloy extruding hollow blade characterized by being formed by joining a coating having zinc embrittlement resistance to the root part of the. 2. The zinc-containing aluminum alloy extruding holloidice according to claim 1, wherein the root portion where the coating is formed is a surface of a bridge that supports a mandrel.