JPH07216490A - Tungsten alloy for golf club heads - Google Patents

Abstract

(57) [Summary] [Purpose] It is suitable for manufacturing small heads, and allows golfers to select the putter with the most suitable weight from the same model according to their physical strength, skill, preference, etc. Provided is a tungsten alloy for a head of a golf club to be smoothed. A tungsten alloy containing at least tungsten and one or more metals selected from the group consisting of nickel, molybdenum, and cobalt having a smaller specific gravity than tungsten, wherein the content of tungsten is: The content of the metal such as nickel is 40% by weight or more and less than 100% by weight, and the content of the metal such as nickel is more than 60% by weight and more than the amount that can be contained as inevitable impurities. [Effect] A small and thin putter head with a standard weight is provided, and putters with different head weights are provided with the same model, and the head volume when manufacturing a head with a standard weight by adjusting the specific gravity is provided. Restrictions are relaxed, and various shapes of heads can be designed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tungsten alloy, for example, a tungsten alloy suitable as a head material for golf clubs, especially putters.

[0002]

2. Description of the Related Art Conventionally, a putter head, which is one of golf clubs, is generally made of iron, stainless steel, or the like, and is manufactured by casting or forging. The standard weight of the head is about 350 g due to the ease of use and the like, and various shapes are commercially available.

[0003]

Since the specific gravity of the conventional head material is as small as about 8, the head having the standard weight has a relatively large shape. An increasing number of golfers want a putter with a thin head. However, if the head is miniaturized using the above conventional material, the standard weight is 350.
Since it is lighter than g, the usability may be deteriorated.

In the case of a conventional cast putter,
As a standard weight head is cast, a mold with an internal volume corresponding to the specific gravity of iron or the like is produced, and molten iron or the like is poured into the mold to solidify, so depending on the preference of the golfer to use. The same model, that is, a putter having the same shape and the same size but having different head weights every several g was not commercially available. Therefore, conventionally, golfers have been inconvenient because they cannot select putters having different weights from the same model according to their physical strength, skill, and preference.

The present invention has been made to solve the above problems, and an object thereof is to provide a tungsten alloy for a head of a golf club, which is suitable for manufacturing a small head. . We also provide tungsten alloys for golf club heads that allow golfers to select the optimum putter weight according to their physical fitness, skill, preference, etc. Especially.

[0006]

In order to achieve the above object, the present inventor has found that in order to miniaturize the head of a putter, tungsten (W) having a larger specific gravity than conventional iron, stainless steel, etc. is used as a head material. ) Was thought to be effective. However, since the specific gravity of tungsten exceeds 19, not only is it too heavy as a head material, but it is difficult to manufacture with only tungsten because of poor workability and the like. Therefore,
The present inventor uses tungsten and nickel (Ni) or molybdenum (Mo) having a smaller specific gravity than tungsten as a head material.
The present invention has been completed in consideration of manufacturing a head by a powder metallurgy method using a tungsten alloy composed of a metal such as cobalt or cobalt (Co).

That is, the tungsten alloy for a golf club head according to the present invention contains at least tungsten.
A tungsten alloy containing a specific gravity adjusting element having a specific gravity smaller than that of tungsten, wherein the content of the tungsten is 40% by weight or more and less than 100% by weight, and the content of the specific gravity adjusting element is The amount is more than the amount that can be contained as unavoidable impurities and is 60% by weight or less.

The specific gravity adjusting element is nickel,
It is characterized by being one or more metals selected from the group consisting of molybdenum and cobalt.

Further, the tungsten alloy for a head of a golf club according to the present invention contains at least one of 0.1% by weight to 3% by weight of copper and 0.1% by weight to 3% by weight of iron. It is characterized by

The tungsten alloy is sintered in the solid phase. This is because, as described above, the allowable range of the content of tungsten reaches a relatively small value, and when liquid phase sintering is performed when the content of tungsten is small, the powder compact is produced at the time of sintering. This is because it is not possible to maintain the molded shape of and is deformed.

The reasons for selecting each of the above elements and the range of their contents will be described below.

The reason why the content of tungsten is 40% by weight or more is that if it is less than 40% by weight, a specific gravity suitable as a head material used for a small head cannot be obtained. On the other hand, the content of tungsten is less than 100% by weight. When the content of tungsten is 100%, the melting point of tungsten is 3380 ° C., so that the sinterability becomes extremely poor and the content must be extremely high. This is because it does not sinter.

The lower limit of the content of the specific gravity adjusting element exceeds the amount that can be contained as an unavoidable impurity, as long as the specific gravity adjusting element is contained in a small amount, tungsten 1
Not only the effect of making the specific gravity smaller than that of 00% can be obtained, but also the sintering temperature can be set to a temperature industrially applicable, for example, lower than 1510 ° C. which is the eutectic temperature of tungsten and nickel. Because you can. On the other hand, the reason why the content of the specific gravity adjusting element is 60% by weight or less is that tungsten accounts for 40% by weight or more with respect to the tungsten alloy as described above.

As the specific gravity adjusting element, nickel,
Molybdenum, cobalt and the like are used because their specific gravities are about half of those of tungsten, and the addition of an appropriate amount can widen the range for adjusting the specific gravity of the tungsten alloy.

Further, the reason why copper (Cu) or iron (Fe) is added is that the addition thereof causes the hardness of the tungsten alloy to be lowered and the workability such as cutting and mechanical polishing to be improved.

The content of the copper or iron is 0.1
The reason why it is at least wt% is that if it is less than 0.1 wt%, the hardness is hardly reduced and the workability is not improved.
The content of copper is 3% by weight or less because if it exceeds 3% by weight, densification during sintering is hindered. The iron content is 3% by weight or less because if it exceeds 3% by weight, the head obtained by sintering may rust over time, but preferably the iron content is Is 1% by weight
The following is good.

Even if the content of copper exceeds the above upper limit, it is possible to densify by increasing the sintering temperature and prolonging the sintering time. Therefore, in the tungsten alloy according to the present invention, copper is used. Needless to say, the content of may exceed 3% by weight. However, if the content of copper is increased, the liquid phase generation temperature becomes low and liquid phase sintering is likely to occur, and there is a possibility that the shape cannot be retained, and the extension of the sintering time causes a decrease in production efficiency. For that reason, the content of copper is preferably 3% by weight or less.

When the corrosion resistance of the head is improved by subjecting the head obtained by sintering to a corrosion-resistant protective film to improve the corrosion resistance of the head, the iron content exceeds 3% by weight. Needless to say, it may be included.

[0019]

According to the above-mentioned means, the tungsten alloy for a head of a golf club according to the present invention has a high specific gravity of 40% by weight or more and less than 100% by weight, and a specific gravity adjusting element having a smaller specific gravity than tungsten as an unavoidable impurity. The content of the head exceeds 60 wt% and the content of the head is 60 wt% or less. Therefore, the head can be miniaturized with the standard weight. Further, by adjusting the composition ratio of the specific gravity adjusting element and tungsten, for example, when the specific gravity adjusting element is nickel, the specific gravity of the tungsten alloy is set to 1
It can be arbitrarily adjusted within the range of about 1.3 to 19.2.

Further, since the eutectic temperature of tungsten and nickel is about 1510 ° C., by adding nickel to tungsten, even if the addition amount is very small,
The liquidus formation temperature of tungsten alloy is 100
Significantly below the melting point of%. Since the tungsten alloy according to the present invention is sintered in a solid phase, the sintering temperature can be set to a temperature lower than 1510 ° C. by adding nickel, and the sinterability is improved.

Since cobalt has the same specific gravity as nickel and molybdenum has a slightly higher specific gravity than nickel, even if cobalt or molybdenum is used instead of nickel or together with nickel, the specific gravity of the alloy is 11.3.
It can be arbitrarily adjusted in a wide range of about 19.2.

Furthermore, by adding copper or iron, the hardness of the head obtained by sintering is lowered, and the workability such as cutting or mechanical polishing is improved.

Therefore, a small and thin putter head having a standard weight is provided, and putters having the same model but different head weights are provided, and further, by adjusting the specific gravity, a head having a standard weight is manufactured. The restrictions on the head volume are relaxed, and it becomes possible to design heads of various shapes.

[0024]

EXAMPLES The features of the present invention will be clarified below with reference to Examples and Comparative Examples. In each example and each comparative example, first, a tungsten powder (purity: 99.
99%), nickel (element for adjusting specific gravity) powder, copper powder,
From the iron powder and the molybdenum (element for adjusting specific gravity) powder, an appropriate amount of powder was selected and mixed with a mixer so that a tungsten alloy sintered body having a desired composition was obtained. Then, each mixed powder was compression-molded at a pressure of 2.0 ton / cm ² by a cold isostatic pressing (CIP molding) method, and each of the obtained molded bodies was solid-phase sintered in a hydrogen atmosphere to be sintered. I got a union. The specific gravity (Archimedes method) and Vickers hardness (JIS Z 2244) of each of the obtained sintered bodies were measured, and the sintered bodies were immersed in tap water for 1 week to examine the corrosion resistance.

(Examples 1 to 6 and Comparative Examples 1 and 2) In Examples 1 to 6 and Comparative Examples 1 and 2, a tungsten alloy (excluding Comparative Example 1) having a composition consisting of tungsten and nickel alone was sintered. Got the body In Examples 1 to 6, the content of tungsten was changed from 99.9% by weight to 40.0% by weight. In Comparative Example 1, the composition was 100% tungsten in which nickel was not intentionally added, and in Comparative Example 2, 3%.
A tungsten alloy having a composition of 0.0 wt% tungsten and 70.0 wt% nickel was produced.

The composition of each sintered body obtained in Table 1 and Table 2,
Sintering temperature, sintering time (time kept at the sintering temperature), specific gravity and Vickers hardness are shown.

[Table 1]

[Table 2]

From these tables, in Examples 1 to 6, when the tungsten content is 40% by weight or more and less than 100% by weight, sufficient hardness can be obtained, and the tungsten alloy is reduced as the content of tungsten decreases. It can be seen that the specific gravity of 1 tends to decrease from 19.2 to 11.3. Therefore, since a tungsten alloy having an arbitrary specific gravity between 11.3 and 19.2 can be obtained, it is suitable as a head material for a putter.

In Comparative Example 1, sufficient densification does not occur and the specific gravity is too small, but this is because the sintering temperature is too low as compared with the melting point of tungsten and it is difficult to sinter, so that it is not suitable as a head material. is there. In Comparative Example 2, the amount of tungsten is too small to obtain a sufficient specific gravity, which is unsuitable as a head material.

(Examples 7 to 10 and Comparative Example 3) Example 7
10 to Comparative Example 3, a tungsten alloy sintered body having a composition of 63 wt% tungsten, nickel and copper was obtained. In Examples 7 to 10, the content of copper was changed from 0.1% by weight to 3.0% by weight. In Comparative Example 3, the copper content was 10.0% by weight.

The composition of each sintered body obtained in Table 1 and Table 2,
The sintering temperature, sintering time, specific gravity and Vickers hardness are shown. From these tables, in Examples 7 to 10, not only the specific gravity and hardness suitable as the head material of the putter can be obtained, but also the hardness of the tungsten alloy tends to decrease by increasing the copper content. It can be seen (compared with the hardness of Example 5). Therefore, the workability of the tungsten alloy such as cutting and mechanical polishing is improved, and it is suitable as a head material for putter.

In Comparative Example 3, since the amount of copper was too much and the liquidus formation temperature was lowered, the sintering temperature was correspondingly lowered, and sufficient densification did not occur, resulting in a specific gravity as a putter head material. Is too small. Further, it takes an extremely long time (100 hours) for sintering to sufficiently densify, the production efficiency is poor, and it is unsuitable as a head material from the viewpoint of industrial production.

(Examples 11 and 12 and Comparative Example 4) In Examples 11 and 12 and Comparative Example 4, a tungsten alloy sintered body having a composition of 70.0 wt% tungsten, nickel and iron was obtained. The iron content was set to 0.1 in Example 11.
% By weight, 1.0% by weight in Example 12 and 1 in Comparative Example 4.
It was set to 0.0% by weight.

The composition of each sintered body obtained in Tables 1 and 2,
The sintering temperature, sintering time, specific gravity and Vickers hardness are shown. From these tables, in Examples 11 and 12, not only the specific gravity and hardness suitable as the head material of the putter are obtained, but also the hardness of the tungsten alloy tends to be lowered by increasing the iron content. It is understood (compared with the hardness of Example 4). Therefore, the workability of the tungsten alloy such as cutting and mechanical polishing is improved, and it is suitable as a head material for putter.

In Comparative Example 4, when the amount of iron is too large to cause rust, and the rust-proofing treatment such as covering the sintered body with the corrosion-resistant protective film is not performed, it is unsuitable as a head material for a putter. Is. In addition, other Examples 1 to 1 except for this Comparative Example 4
In No. 7 and Comparative Examples 1 to 3, no rust was found.

(Examples 13 and 14) In Examples 13 and 14, sintered bodies of tungsten alloy having a composition of 63% by weight of tungsten, nickel, copper and iron were obtained. Example 1
In Example 3, both the contents of copper and iron were set to 0.1% by weight, and in Example 14, the contents of copper and iron were both set to 1.
It was set to 0% by weight.

Table 1 shows the composition, sintering temperature, sintering time, specific gravity and Vickers hardness of each of the obtained sintered bodies. From the same table, not only the specific gravity and hardness suitable as the head material of the putter can be obtained by adding both copper and iron, but also when they are individually added (the above Examples 7 to 12). However, it is understood that the hardness of the tungsten alloy tends to decrease by increasing the contents thereof (compared with the hardness of Example 5). Therefore, the workability of the tungsten alloy is improved, and it is suitable as a head material for a putter.

Examples 15 to 17 In Examples 15 to 17, sintered bodies of tungsten alloy having a composition of tungsten, 1.0% by weight of nickel and molybdenum were obtained. In Examples 15 to 17, the content of molybdenum was changed from 9.0% by weight to 49.0% by weight.

Table 1 shows the composition, sintering temperature, sintering time, specific gravity and Vickers hardness of each of the obtained sintered bodies. From the table, when the content of tungsten is 40% by weight or more and less than 100% by weight, sufficient hardness can be obtained even when both nickel and molybdenum are mixed as elements for adjusting specific gravity, and the content of molybdenum increases. It can be seen that the specific gravity of the tungsten alloy tends to decrease with the increase in temperature. Therefore, the specific gravity of the tungsten alloy can be adjusted,
It is suitable as a head material for putters.

By the way, Examples 1 to 6 and Comparative Examples 1 and 2
The sintering temperature is 1500 ° C., but the eutectic temperature of the tungsten-nickel binary alloy is 151 as described above.
Since the temperature is 0 ° C. and the melting point of tungsten is 3380 ° C., each of the compacts is solid-phase sintered. In addition, in Examples 7 to 17 and Comparative Examples 3 and 4, the sintering temperature was 15 as the content of copper, iron, molybdenum, etc. increased.
The temperature decreases with increasing distance from 00 ° C. This is because the liquid phase formation temperature lowers as the content of them increases, and the sintering temperature should be lower than the liquid phase formation temperature by several to several tens of degrees Celsius. Since, in each of these cases, each of the compacts is solid-phase sintered.

The present invention is not limited to the above embodiments. For example, the content of tungsten is 40% by weight or more and less than 100% by weight, and the content of the specific gravity adjusting element such as nickel or molybdenum exceeds the amount that can be contained as an unavoidable impurity and is 60% by weight.
The following is acceptable. Needless to say, the contents of copper, iron, and molybdenum are not limited to those in the above-mentioned examples.

Further, as a specific gravity adjusting element, not only nickel or molybdenum but also cobalt is used as long as the specific gravity is smaller than that of tungsten and the addition thereof does not bring about demerits such as significant embrittlement, deterioration of corrosion resistance and deterioration of sinterability. Other elements may also be used.

Further, in the sintered body made of the tungsten alloy according to the present invention, the specific gravity is adjusted by changing the content of nickel or the like, but the specific gravity is adjusted by adjusting the porosity of the sintered body. You can also Also,
By changing the porosity, the feel when hitting a golf ball and the hitting sound are changed, so that a comfortable hitting feeling can be obtained by appropriately adjusting the porosity.

Further, the tungsten alloy according to the present invention can be applied not only to putters but also to head materials of other golf clubs such as irons, and other than golf clubs, other sports equipment, stationery and machine parts. Of course, it is also useful as a material for metal products in general, such as construction materials.

[0044]

According to the tungsten alloy for a golf club head according to the present invention, tungsten having a high specific gravity of 40 is used.
The standard weight (approximately 350 g) is contained because the content of each element is not less than 100% by weight and not less than 100% by weight, and more than 60% by weight and more than the amount that can be contained as an unavoidable impurity as a gravity adjusting element having a smaller specific gravity than tungsten. The head can be miniaturized as it is, and the specific gravity of the tungsten alloy can be arbitrarily adjusted in a wide range of about 11.3 to 19.2 by adjusting the composition ratio of the specific gravity adjusting element and tungsten. it can.

Therefore, a small and thin putter head having a standard weight is provided, and putters having the same model but different head weights are provided, and a head having a standard weight is manufactured by adjusting specific gravity. The restrictions on the volume are relaxed, and various shapes of heads can be designed.

Claims (3)

[Claims] 1. A tungsten alloy containing at least tungsten and a specific gravity adjusting element having a specific gravity smaller than that of tungsten, wherein the content of tungsten is 40% by weight or more and less than 100% by weight. The tungsten alloy for a golf club head, wherein the content of the specific gravity adjusting element is more than 60 wt% and more than the amount that can be contained as an unavoidable impurity. 2. The tungsten alloy for a head of a golf club according to claim 1, wherein the specific gravity adjusting element is one or more metals selected from the group consisting of nickel, molybdenum and cobalt. 3. The golf according to claim 1, comprising at least one of 0.1% by weight to 3% by weight of copper and 0.1% by weight to 3% by weight of iron. Tungsten alloy for club heads.