JPH05208296A - Aluminum alloy filler metal for mold - Google Patents

Abstract

PURPOSE:To provide the filler metal which does not generate weld cracks even in repair welding of an aluminum alloy for molds for plastics, etc., and more particularly Al-Zn-Mg-Cu alloys, improves the strength of weld zones and exhibits the etching property equiv. to the etching property of a base material in spite of photoetching. CONSTITUTION:This filler metal contains 4 to 13% Si, 0.1 to 1% Fe, 0.1 to 1% Mg and 0.1 to 1% Mn, further contains >=2 kinds among 0.05 to 0.2% Ti, 0.01 to o.2% B, 0.05 to 0.3% Zr, 0.05 to 0.5% Na, 0.03 to 0.5% Sb and 0.03 to 0.5% Sr at need and consists of the balance Al and unavoidable impurities.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filler material used for welding aluminum alloy molds for molding plastics and the like.

[0002]

2. Description of the Related Art Molds for molding plastic and the like have hitherto been
Some of them were made of steel, but they had drawbacks such as heavy weight, poor workability, and easy rusting. In order to solve these problems, an aluminum alloy has recently been used in a mold.

When an aluminum alloy is used for the mold,
Compared with steel molds, thermal conductivity is good, so the shot cycle is short, productivity is improved, workability is good, processing time is shortened, weight is 1/3 light and rust Since it is difficult, it has features such as easy attachment / detachment and maintenance.

[0004]

The mold must be repaired and welded due to design changes, processing errors and the like. However, aluminum alloys used in molds, especially 7000 series alloys
(For example, 7 of the highest strength among aluminum alloys
075) has very poor weldability, and welding has generally been avoided. As an exception, Al-Si based filler metal (eg 4043 or 4
(047 etc.) are used for welding, but the strength difference between the welded part and the base metal part is large.
There was a problem that the bead marks on the welded part were transferred to the product.

In the Al-Si type filler material, Si, which has good fluidity, is the main additive element for the purpose of improving the crack sensitivity of the weld metal. Therefore, since the composition of the weld metal part is different from that of the base metal part, the weld metal part is softer than the base metal part, and the strength difference between the two is large. In order to increase the strength of the welded portion, it is necessary to use a filler metal such as a metal alloy or an Al-Mg filler, but it cannot be used because of its high susceptibility to cracking. For this reason, when an Al--Si based filler material is used, a difference in strength between the two is unavoidable, and there is a problem in terms of wear resistance.

Further, the welded portion using the Al-Si based filler material and the Al-Zn-Mg-Cu based base material portion have different photoetching properties because of different alloy components, and the bead of the welded portion is different. There was a problem that marks were transferred to the product.

Although an aluminum alloy filler material is proposed in Japanese Patent Laid-Open No. 143792, the weld metal portion is insufficient from the viewpoint of improving strength and improving photoetching property as described above.

The present invention has been made in view of such circumstances, and welding cracks are generated even in repair welding of aluminum alloys for molding dies such as plastics, especially Al-Zn-Mg-Cu alloys. And the strength of the weld is improved,
Further, it is another object of the present invention to provide a filler material which is photoetched and has the same etching property as the base material.

[0009]

The present inventor has conducted extensive studies to improve the above-mentioned drawbacks of the conventional filler metal, and as a result, in the welding of a mold made of a 7000 series aluminum alloy, Al- It has been found that a filler metal containing a predetermined amount of Fe, Mg, and Mn in a Si-based alloy does not cause weld cracking, improves the strength of the weld, and exhibits the same etching properties as the base metal. The present invention has been completed.

That is, according to the present invention, Si: 4 to 13%, F
e: 0.1 to 1%, Mg: 0.1 to 1%, Mn: 0.1 to 1%, and if necessary, Ti: 0.05 to 0.2%,
B: 0.01 to 0.2%, Zr: 0.05 to 0.3%, Na: 0.0.
05-0.5%, Sb: 0.03-0.5% and Sr: 0.03
SUMMARY OF THE INVENTION An essential feature of the present invention is an aluminum alloy filler material for a molding die, characterized in that it contains two or more of 0.5 to 0.5% and the balance is Al and unavoidable impurities.

The present invention will be described in more detail below.

[0012]

[Action]

The reasons for limiting the chemical components in the filler metal of the present invention are as follows.

Si improves the flowability of molten metal and improves weld cracking, but if it is less than 4%, the improvement of weld cracking is not sufficient.
If it exceeds 13%, the photoetching property is different from that of the base material, and bead marks are transferred to the product, which is not preferable. Therefore,
The amount of Si shall be 4-13%.

Fe acts as a strength enhancing element,
If it is less than 0.1%, its effect is small, and if it exceeds 1%, toughness and photoetching property are deteriorated, which is not preferable. Therefore, the Fe amount is set in the range of 0.1 to 1%.

Although Mg acts as a strength-enhancing element,
If it is less than 0.1%, the effect is small, and if it is 1% or more, toughness and photoetching property are deteriorated, which is not preferable. Therefore, Mg
The amount is in the range of 0.1 to 1%.

Mn acts as a strength enhancing element,
If it is less than 0.1%, the effect is small, and if it is 1% or more, toughness and photoetching property are deteriorated, which is not preferable. Therefore, Mn
The amount is in the range of 0.1 to 1%.

Although the above elements are essential components, two or more of the following elements can be contained in appropriate amounts.

Ti improves the weld crackability by refining the crystal grains, but if it is less than 0.05%, the improvement effect is small,
On the other hand, if it exceeds 0.2%, the toughness is lowered, which is not preferable. Therefore, the Ti content is set in the range of 0.05 to 0.2%.

B improves the weld cracking property by the effect of refining the crystal grains, but if it is less than 0.01%, the improving effect is small, and if it exceeds 0.2%, the toughness is lowered, which is not preferable. Therefore, the amount of B is set in the range of 0.01 to 0.2%.

Zr acts as an element for improving the weld cracking property by the effect of refining the crystal grains, but if it is less than 0.05%, the improving effect is small, and if it exceeds 0.3%, a huge crystallized product is formed. It is not preferable because it deteriorates workability. Therefore, the amount of Zr is set in the range of 0.05 to 0.3%.

Na contributes to the refinement of Al-Si crystallized substances to improve the strength and the machinability, but if it is less than 0.05%, the improving effect is small, and if it exceeds 0.5%, the toughness is lowered. It is not preferable. Therefore, the amount of Na is 0.05 to 0.5.
The range is%.

Like Na, Sb acts as a refining element for Al-Si crystallized substances and contributes to the improvement of strength and machinability. However, if it is less than 0.03%, the improvement effect is small, and 0.0 5%
If it exceeds, the toughness is lowered, which is not preferable. Therefore, the amount of Sb is made into 0.03 to 0.5% of range.

Sr, like Na and Sb, contributes to the structural improvement of the Al-Si alloy, but if it is less than 0.03%, the improvement effect is small, and if it exceeds 0.5%, it is the same as Na or Sb. It is not preferable because it causes deterioration of toughness. Therefore, Sr
The amount should be in the range of 0.03 to 0.5%.

Aluminum alloys having various components and compositions can be used as the base metal for the mold to be welded using the filler metal of the present invention, but the 7000 series alloy is most effective. Also, the welding method is not particularly limited.

Next, examples of the present invention will be described.

[0027]

【Example】

[Table 1] An aluminum alloy having the chemical composition shown in (1) was cast by a conventional method to produce a welding rod having a diameter of 3.2 mm, which was used for the TIG welding test. As the base material, A7075-T6 which is an Al-Zn-Mg-Cu based alloy was used. In the table, No. 1 to N
No. 5 is the alloy of the present invention, No. 6 to No. 25 are comparative alloys, and No. 26 is the conventional alloy (A4043).

In the TIG welding test, as shown in FIG. 2, a V-shaped groove 3 having a depth of 5 mm and a groove angle of 90 ° is provided in the central portion of the test plate 1 having the shape and dimensions shown in FIG. The groove of the base material 2 is formed by the AC / TIG welding method.

[Table 2] The overlay welding was performed under the welding conditions shown in. After that, the weld bead surplus portion was removed and flat finishing was performed.

This material was tested for weld crackability and photoetchability required for a molding die for plastics and the like. Regarding the weld cracking property, the presence or absence of cracks on the surface of the welded portion was examined by the penetrant flaw detection test method. As for the photo-etching property, the material having the welded portion 5 finished as shown in FIG. 3 was divided into three equal parts and photo-etched, and those in which the bead mark was not transferred to the resin surface were marked with ◯, and those transferred. Was judged as x. In the strength test, a test piece for hardness measurement was manufactured from the test plate subjected to the overlay welding shown in FIG. 2, and the hardness of the weld metal part was measured by Vickers (load 5 kg). Judgment was made with a hardness value 10 or more higher than that of normal alloy A4043.
Equivalents from 0 or less were evaluated as x.

These test results

[Table 3] Shown in.

The comparative alloy No. 6 has a small amount of Si and is not sufficiently improved in crack susceptibility. No. 7 has a large amount of Si and is not preferable because the photoetching property is different from the base material.

The comparative alloy No. 8 has a small amount of Fe and does not contribute to the improvement of strength. No. 9 is not preferable because the Fe content is large and the toughness, corrosion resistance and photoetching property deteriorate.

The comparative alloy No. 10 has a small amount of Mg, and has little effect of improving strength. No. 11 is not preferable because it has a large amount of Mg and deteriorates weld crack sensitivity, toughness and photoetching property.

The comparative alloy No. 12 has a small amount of Mn and has a small effect of improving strength. No. 13 has a large amount of Mn and deteriorates the toughness and the photoetching property, which is not preferable.

The comparative alloy No. 14 has a small amount of Ti and has little effect of improving the weld cracking property. No. 15 has a large amount of Ti, and the toughness and photoetching property are deteriorated.

The comparative alloy No. 16 has a small amount of B and little improvement effect on strength and machinability. No. 17 has a large amount of B and deteriorates the toughness photoetching property.

The comparative alloy No. 18 has a small amount of Zr and has little effect of improving the weld cracking property. No. 19 is not preferable because it has a large amount of Zr and forms a huge crystallized substance, which deteriorates workability and photoetching property.

The comparative alloy No. 20 has a small amount of Na, and has little effect of improving strength and machinability. No. 21 is not preferable because it has a large amount of Na and causes a decrease in toughness.

The comparative alloy No. 22 has a small amount of Sb and has little effect of improving strength and machinability. No. 23 is not preferable because it has a large amount of Sb and causes a decrease in toughness.

The comparative alloy No. 24 has a small amount of Sr and has little effect of improving strength and machinability. No. 25 is not preferable because it has a large amount of Sr and causes deterioration in toughness.

On the other hand, the alloys of the present invention are
It can be seen that weld cracking did not occur, the strength of the welded portion was improved, and the bead traces due to photoetching were not observed, and the photoetchability was improved.

[0042]

As described in detail above, according to the filler material of the present invention, an aluminum alloy for molding dies for plastics,
In particular, even when welding an Al-Zn-Mg-Cu alloy, welding cracks do not occur, the strength of the welded portion is improved, and when photoetching is performed, a good surface is obtained in which the weld bead trace is not transferred to a product such as plastic. Be done. As described above, the filler material of the present invention has a remarkable industrial effect.

[Brief description of drawings]

FIG. 1 is a perspective view showing the dimensions and shape of a welding test plate material.

FIG. 2 is a side view for explaining the procedure of TIG welding.

FIG. 3 is a perspective view of a mold material having a welded portion after finishing welding.

[Explanation of symbols]

 1 Welding test plate material 2 Welding base material 3 V-shaped groove 4 Welded portion 5 Finished welded portion

Claims (2)

[Claims] 1. In weight% (hereinafter the same), Si: 4 to 13
%, Fe: 0.1 to 1%, Mg: 0.1 to 1%, Mn: 0.1 to
An aluminum alloy filler material for a molding die, which contains 1% and the balance is Al and inevitable impurities. 2. Si: 4 to 13%, Fe: 0.1 to 1%, M
g: 0.1 to 1%, Mn: 0.1 to 1%, and Ti:
0.05-0.2%, B: 0.01-0.2%, Zr: 0.05
Up to 0.3%, Na: 0.05 to 0.5%, Sb: 0.03 to 0.0.
5% and Sr: 0.03 to 0.5%, two or more of which are contained, with the balance being Al and inevitable impurities, and an aluminum alloy filler material for a molding die.