JPWO2004042096A1 - Low rigidity and high strength titanium alloy with excellent cold workability, glasses frame and golf club head - Google Patents

Abstract

Nb: 1 to 20%, V: 10 to 25%, Al: 2 to 5%, Zr: more than 3% and 10% or less, O: 0.30% or less, with the balance being Ti and inevitable It is made of an impurity element. In place of a part of the Ti, one or more of Sn, Ta, W, Mo, and Cr can be added to improve the strength. It is preferable that the content is% by mass, 25% or less as a whole, Sn is 5% or less, and the total of Ta, W, Mo and Cr is 20% or less.

Description

  INDUSTRIAL APPLICABILITY The present invention is used in medical fields and eyeglass frames where high strength and low rigidity are required, and is based on a titanium alloy premised on manufacturing by a melting method, which is a low-cost manufacturing method, and an eyeglass frame formed from the alloy. And a golf club head.

Titanium alloys, which are lighter and stronger than iron and have excellent corrosion resistance and biocompatibility, are widely used in medical fields such as artificial bones and joints, and accessories such as eyeglass frames and watches. It is coming. When used for such applications, compatibility with the human body is the most important requirement, but since the problem of nickel allergy to the human body became apparent, in applying titanium alloys in these fields, More rigorous evaluations have been made, and the required level of each characteristic has increased. In particular, when used in applications such as the medical field and accessories, not only the compatibility with human tissues but also the problem of wearability is a major consideration. As a result, there has been a strong demand for the development of a material that returns to its original shape, is difficult to be permanently deformed, and can be reduced in weight, that is, an alloy having low rigidity and high strength.
In response to this requirement, a novel alloy obtained by improving a conventional titanium alloy is disclosed in the patent literature. For example, Patent Document 1 discloses a titanium alloy containing 10% to 20% or 35% to 50% niobium in mass% and 20% or less zirconium in weight, and Patent Document 2 discloses Al to 0%. Disclosed is a titanium alloy containing 5 to less than 2.0%, Mo containing 5.0 to 10.0%, V containing 8 to 12%, Zr containing 3 to 6%, and optionally containing Nb and Ta. (See Patent Documents 1 and 2). Patent Document 3 contains a titanium alloy containing 30 to 60% by mass of a vanadium group element, and the alloy contains one or more elements in a metal element composed of zirconium, hafnium, and scandium in a total of 20% by mass or less. Alloys containing 0.08 to 0.6% by mass of oxygen in these alloys or further to these titanium alloys are disclosed (see Patent Document 3).
Titanium alloys are widely used for golf club heads because of their low specific gravity compared to iron, excellent corrosion resistance, and high specific strength. 15-3-3-3 alloy (15% V-3% Al-3% Cr-3% Sn-76% Ti), 15-5-3 alloy (15% Mo-5%), which is an alloy having excellent strength Β-type titanium alloys such as Zr-3% Al-77% Ti) are used. Further, an invention is disclosed in which the alloy described in Patent Document 3 is applicable not only to decorative items but also to golf clubs because it has a high specific Young's modulus and is suitable for golf clubs (face part and shaft). (See Patent Document 4).
[Patent Document 1] JP-A-6-73475 [Patent Document 2] JP-A-2-138429 [Patent Document 3] JP-A-2001-247924 [Patent Document 4] JP-A-2001-246029 However, The alloy described in the above publication has the following problems.
Patent Document 1 describes a low-rigidity titanium alloy that can be increased in strength by aging treatment. With reference to the examples described in this document, the obtained tensile strength is less than 1000 MPa even after aging treatment. is there. Moreover, although it is described that high strength exceeding 1000 MPa can be secured by performing cold working, it is possible strength when performing aging treatment even in the case of cold working, and exceeds 1000 MPa without heat treatment. Strength has not been achieved. In addition, as is clear from the description of the examples of Patent Document 1, when the aging treatment is performed, the strength is improved, but at the same time, the Young's modulus is also increased, and the characteristic of low rigidity where the folding angle is obtained is lost. There's a problem. Further, the necessity of the aging process means that the number of processes increases, and there is a problem that the process becomes complicated. The titanium alloy described in Patent Document 2 is similar to the alloy described in Patent Document 1, and it is described that a strength of 1000 MPa or more can be obtained, but the high strength is based on the premise that an aging treatment is performed. There is no characteristic of low rigidity.
In addition, it is possible to increase the strength by adding elements such as aluminum and oxygen. However, when these elements are simply added to the alloy of Patent Document 1, cold workability is reduced, and a thin wire rod is formed. There are problems that it is difficult to manufacture, and that the Young's modulus increases, so that the wearability is lowered when used as a spectacle frame.
Patent Document 3 and Patent Document 4 describing the Ti alloy for golf clubs describe the alloys having a tensile elastic limit strength of 1000 MPa or more in some invention alloys. Although the invention described in the literature is not clearly described in the scope of claims, as is apparent from the description of the examples, the invention is based on the premise that it is substantially manufactured by sintering. In the examples of this document, a large number of alloys containing 30% or more of Nb are described. As a result of confirmation by the present inventors through experiments, such a large amount of Nb-containing alloy is produced by a melting method. It has been found that it is difficult to produce an ingot having a uniform component, and it is difficult to produce a material having properties such as strength that are uniform in strength by a melting method. In the case of being limited to the sintering method, there is a problem that the cost becomes significantly higher than the production by the melting method and it is difficult to reduce the cost.

The present invention has a low Young's modulus and good cold workability, can easily achieve a high strength of 1000 MPa or more without relying on an aging treatment, and maintains high wearability when applied to jewelry. It is possible to manufacture lightweight products while providing a low-rigidity and high-strength titanium alloy that can be manufactured by the melting method, and it is possible to manufacture a glass frame that is lightweight and improves wearability using the alloy. One purpose is to do.
Another object of the present invention is to provide a new titanium alloy capable of obtaining a large flight distance when applied to the face portion of a golf club head.
In order to solve the above-mentioned problems, the present inventors have conducted intensive research to find a range of components that can be obtained with excellent properties for all of high strength, low rigidity, and cold workability, and that can be manufactured by a melting method. As a result, the following knowledge was obtained and the present invention was completed.
(1) Titanium alloys usually have a Young's modulus of about 80 to 110 GPa, but when an appropriate amount of Nb and V is added, thermoelastic martensite is generated by stress-induced transformation at a low stress below the yield stress. As a result, an apparent distortion occurs, and when the stress is removed, the original matrix is restored by reverse transformation, so that the Young's modulus can be lowered. In this respect, the inventions of Patent Documents 3 and 4 are the same, but in the invention based on the premise of manufacturing by sintering as in Patent Documents 3 and 4, a large amount of Nb can be added. It has been found that by controlling the upper limit of the content rate to 20%, it is possible to produce not only by sintering but also by a melting method. In addition, due to the effect of addition of Al and Zr, which will be described later, it is possible to achieve a high strength of a tensile strength of 1000 MPa or more only by cold working without relying on an aging treatment, and to make it compatible with the low rigidity obtained by generating thermoelastic martensite. (2) In order to increase the strength while maintaining excellent cold workability and low rigidity for the alloy described in (1), it is effective and necessary to add Al and Zr in combination. An appropriate addition range for ensuring cold workability was found.
(3) In order to improve the flight distance of the golf club and make it possible to fly far away, the deflection of the face portion becomes large at the moment the ball hits the face portion, and the stored elastic energy is large. It is said that it is necessary (for example, refer nonpatent literature 1). That is, it is considered that the stored elastic energy becomes a restoring force and rebounds the ball.
[Non-Patent Document 1] Titanium Vol. 50, no. 3, P185-192
In order to increase the elastic energy that can be accumulated, by having a high strength and making it possible to reduce the plate thickness of the face portion, the deflection is increased when the ball is hit, Two points are important in selecting a material that does not undergo plastic deformation with a larger deflection by lowering the Young's modulus.
Alloys developed with the concepts of (1) and (2) above for the characteristics required for this golf club are very suitable, and the limit strain that returns to its original shape when unloaded even when deformed. It was found that the value was extremely high and high elastic energy could be accumulated.
The present invention has been made by obtaining the above findings (1) to (3).
The first invention completed by obtaining the knowledge described above is mass%, Nb: 1 to 20%, V: 10 to 25%, Al: 2 to 5%, Zr: more than 3% and not more than 10%, O: A low-rigidity and high-strength titanium alloy excellent in cold workability, characterized by containing 0.30% or less and the balance being made of Ti and inevitable impurity elements.
Next, the reason for limiting each component range of the titanium alloy will be described.
Nb: 1-20%, V: 10-25%,
Nb and V are the most important elements for the present invention, and as described above, thermoelastic martensite is generated at the time of stress loading as a result of composite addition of each, and low Young's modulus is obtained by returning to the original matrix at the time of stress removal. Can be achieved. In order to obtain the effect, it is necessary to add in a certain amount. Therefore, the lower limit amounts are set to 1% for Nb and 10% for V. However, if it is added in a large amount, it may be produced by sintering. However, in the production by the melting method, it becomes difficult to produce an ingot having uniform performance, and stable performance cannot be obtained. % And V were 25%.
Note that Nb and V tend to increase in specific gravity as the addition amount increases, and the lightening effect may be reduced. Therefore, when the specific gravity is important, it is desirable that the total content of Nb and V is less than 30%.
In order to further improve the solubility of the titanium alloy, it is preferable to set the upper limits of the Nb and V contents to 5% and 17%, respectively.
Al: 2 to 5%, Zr: more than 3% and 10% or less,
Al and Zr are elements necessary for obtaining high strength of 1000 MPa or more only by cold working without depending on aging treatment. As the added amount of both Al and Zr increases, the high strength effect increases, but in order to obtain the desired strength, at least Al is 2% or more, more preferably 3% or more, Zr exceeds 3%, More preferably, it is necessary to add 4% or more. However, addition of a large amount leads to an increase in Young's modulus and decreases the cold workability. Therefore, to prevent this, the upper limit was made 5% for Al and 10% for Zr. More preferably, the upper limit of Zr is 6%.
O: 0.30% or less,
It is known that O can be increased in strength when added, but there is a problem that cold workability decreases and Young's modulus increases as the amount added increases. Therefore, it is desirable to suppress the amount as much as possible in the present invention which places importance on maintaining excellent cold workability and low rigidity. However, since O is an impurity element that is inevitably mixed during the production, if the upper limit value is extremely lowered, the production becomes difficult. Therefore, the content in the range of 0.30% or less is allowed.
Next, in the titanium alloy, the strength can be improved by adding one or more of Sn, Ta, W, Mo, and Cr in place of a part of the Ti. The content was, by mass, 25% or less as a whole, Sn was 5% or less, and the total of Ta, W, Mo and Cr was 20% or less. The same applies to the second and third inventions described later. Hereinafter, the reasons for limiting the composition range of each element will be described.
Sn, Ta, W, Mo, and Cr are elements that have the effect of further improving the strength by adding to the titanium alloy of the first invention as necessary. However, if it is contained in a large amount, high strength can be obtained, but the Young's modulus increases and it becomes difficult to achieve both high strength and low rigidity, and cold workability deteriorates, making it difficult to manufacture the product. It should be added within a range where the adverse effect on workability and Young's modulus is small (mass% Sn: 5% or less, total of 4 elements of Ta, W, Mo, Cr is 20% or less).
In addition to Nb and V, when Ta is added, the specific gravity tends to increase and the lightening effect tends to decrease. Therefore, when the specific gravity is important, the total content of the three elements is set to 30. It is preferable to make it less than%.
Next, the second invention is a glasses frame formed by using a cold-worked wire made of a titanium alloy as at least a part of the material,
The titanium alloy contains Nb: 1 to 20%, V: 10 to 25%, Al: 2 to 5%, Zr: more than 3% and 10% or less, and O: 0.30% or less in mass%. The eyeglass frame is characterized in that the balance is made of Ti and inevitable impurity elements.
The titanium alloy in the second invention corresponds to the titanium alloy of the first invention described above, and can achieve low rigidity and high strength only by cold working without relying on aging treatment, and a sintering method It is a titanium alloy that can be manufactured at a low cost because it can be manufactured by a melting method. This alloy has excellent properties, so many kinds of accessories, portable goods (watches, earrings, rings, tie pins, brooches, cufflinks, mobile phones, belt buckles, various keys, lighters, various Applicable to medical fields such as writing utensils (ballpoint pens, etc.), key holders, necklaces, bracelets, earrings, fittings such as handbags and wallets), fishing tackle parts, springs, artificial bones, etc. Then, a big effect can be acquired.
In other words, the eyeglass frame is always worn on the face of the person, so there is a strong demand for weight reduction and a fit with the face is required, so it can be easily deformed by an external force and immediately removed. This is because it is necessary to return to the original shape, and the product is most required to have low rigidity and high strength.
By manufacturing a glass frame using a cold-worked wire manufactured from the above titanium alloy, it is excellent in wearability and fit, and can be manufactured at a much lower weight than when a conventional alloy is used. . The eyeglass frame is composed of a temple part, a rim part, and a bridge part, but the alloy of the present invention may be used for all or a part thereof. In particular, the temple part is the part most related to the wearability and fit, so when using the alloy of the present invention for a part, the use of the alloy of the present invention for the temple part provides excellent wearability and fit. A glasses frame can be manufactured. In addition, since the alloy of the present invention has high strength, it is possible to manufacture a glass frame that is significantly lighter than conventional pure titanium frames when used in all the above-described parts. .
Also in the second invention, as described above, in the titanium alloy, one or more of Sn, Ta, W, Mo, and Cr are further substituted for part of the Ti. The total content is preferably 25% or less, and Sn is preferably 5% or less, and the total of Ta, W, Mo and Cr is preferably 20% or less. The reason why it is preferable to add these elements is the same as described above in the reason for limiting the component range of the first invention.
Next, a third invention is a golf club head using a cold-worked plate material made of a titanium alloy for a face portion.
The titanium alloy contains Nb: 1 to 20%, V: 10 to 25%, Al: 2 to 5%, Zr: more than 3% and 10% or less, and O: 0.30% or less in mass%. A golf club head characterized in that the balance is made of Ti and inevitable impurity elements.
The titanium alloy of the third invention also corresponds to the titanium alloy of the first invention, and as described in the explanation of the first invention, the titanium alloy can obtain high strength only by cold working. And low rigidity. As described above, in order to increase the flight distance of the golf ball hit by the club head of the golf club, the face portion is designed to have a large deflection when the golf ball and the club head collide with each other. It is necessary to make more use of the force for returning to the original shape, and it is necessary that no permanent deformation remains even if it is greatly bent. In other words, it is important that the alloy be capable of accumulating large energy within the range of elastic deformation. As a result of investigating the performance of the above-described alloy in detail, the present inventors have found that permanent deformation does not remain up to a strain value that has been almost difficult with conventional alloys, and has a large energy storage capability.
In addition to the face portion, the golf club head includes a crown portion, a sole portion, and a side portion, but these portions may use the alloy of the present invention or other alloys. Recently, however, club heads with a large capacity exceeding 300 ml have been favored, and it is more suitable to use a material having a specific gravity lower than that of Fe, and the alloy of the present invention used for the face portion can be welded. Since it is necessary, it is natural that other parts should be made of a Ti alloy.
Also in the third invention, as described above, in the titanium alloy, one or more of Sn, Ta, W, Mo, and Cr are further substituted for part of the Ti. The total content is preferably 25% or less, and Sn is preferably 5% or less, and the total of Ta, W, Mo and Cr is preferably 20% or less. The reason why it is preferable to add these elements is as described in the above-mentioned reason for limiting the component range of the first invention.

FIG. 1 is an explanatory view showing a glass frame manufactured as an example.
FIG. 2 is an explanatory view showing a wood type golf club head applicable as an embodiment.
FIG. 3 is an explanatory view showing an iron type golf club head applicable as an embodiment.

これらの供試材は、真空２重アーク溶解により溶製された１０ｋｇのインゴット（直径１２０ｍｍ）を熱間鍛造及び熱間圧延で直径６ｍｍの線材とし、表面の酸化層を酸洗で除去し、さらに断面減少率が５０％となる冷間圧延を中間での焼鈍を行わずに実施することにより準備した。そして、得られた供試材を用いて引張強度及びヤング率の測定を行った。
ヤング率は引張試験片に歪ゲージを取り付け、引張試験実施中における応力−歪曲線を測定し、弾性範囲内の前記曲線の勾配から求めた。
冷間加工性は、前記した供試材準備時の減面率５０％の冷間圧延が正常に行うことができた場合を○、割れが発生し正常に圧延できなかった場合を×で示した。前記した表１にその結果を示す。
表１から明らかなように、本発明合金であるＮｏ．１〜１１合金は、いずれも断面減少率５０％の冷間圧延を正常に行うことができ、かつ８０ＧＰａ以下の低いヤング率と１０００ＭＰａ以上の高い引張強度を示し、めがねフレームでの適用時に重要視されるバネ特性に非常に優れていることがわかる。
それに対し比較合金であるＮｏ．１２〜２４合金は、いずれかの元素の含有率が本発明の条件を満足しないために、ヤング率、引張強度、冷間加工性のいずれかが本発明合金に比べ劣るものである。具体的にはＮｏ．１２〜２３合金は、表１で＊で示した元素が範囲外であるため、ヤング率が劣るものであり、Ｎｏ．１６、１８合金は強度向上に効果の大きい元素であるＡｌ、Ｚｒの含有率が低いため、強度が大きく劣るものであり、Ｎｏ．２４合金はＯの含有率が高いため、冷間加工性が大きく低下し、冷間圧延時に割れが発生したものである。
また、従来合金であるＮｏ．２５、２６合金は、従来合金の中で最も高強度の得られる合金であり、強度については優れた値を示しているが、ヤング率が高く、高強度と低剛性の両立ができていないものである。
以上の結果より、本発明合金が優れた特性を有することが明らかになったので、実際に本発明合金を用いて図１に示されるようなめがねフレームを製造した。なお、図中で１はテンプル部、２はリム部、３はブリッジ部である。このうち、１のテンプル部が最も装着性、フィット性の良し悪しに影響の大きい部品であるため、１種類はテンプル部、リム部、ブリッジ部の全てが純チタン（ヤング率１００ＧＰａ、引張強度６００ＭＰａ）からなるめがねフレーム（従来のめがねフレーム）を製造し、もう１種類としてテンプル部のみ表１に示すＮｏ．１に相当する合金を用い、リム部、ブリッジ部は前記と同じ純チタンからなるめがねフレームを製造した。そして、リム部、ブリッジ部については両者とも同じ寸法とし、テンプル部については引張による破断荷重が同一となるよう太さを変更し、長さは同一となるようにして製造した。製造後に重量を測定した結果、純チタンのみから製造しためがねフレームが５．５ｇであったのに対し、テンプル部に本発明合金を用いためがねフレームは４．５ｇと１ｇの軽量化を実現することができた。
この試作しためがねフレームの使用した合金の違いによる効果であるが、装着性、フィット性は個人によっても評価に差が生じ、数値で明確に評価することは困難であるため、無作為に２０人を選び装着性、フィット性について５段階評価を実施（評価が５、４、３、２、１のそれぞれについて点数を５、４、３、２、１として評価）し、その平均点で評価した。その結果、従来合金のみにより製造しためがねフレームが平均３．２点であったのに対し、本発明の合金を使用しためがねフレームは、平均４．４点とかなりの改善がみられた。これは軽量化効果に加え、ヤング率の低下と高強度化により、めがねをかける時にテンプル部の間隔の調整の自由度が大きくなったことにより、フィット性が向上したことが大きな原因と推定される。
次に、本発明からなるＴｉ合金をゴルフクラブヘッドのフェース部に用いた場合に、飛距離の優れたクラブを製造できることを示す別の実施例を示す。実験は、前記実施例で使用した供試合金のうち、本発明合金として１、１０、１１合金、従来合金（１５−３−３−３合金）である２５合金を選択し、前記した引張試験と同じ方法で引張試験片を準備した。
ここで、従来合金として、１５−３−３−３合金である２５合金を選択したのは、１５−５−３合金（１５％Ｍｏ−５％Ｚｒ−３％Ａｌ−７７％Ｔｉ）とともに、従来から知られているＴｉ合金の中でゴルフクラブヘッドのフェース部に現在も最も多く使用されているβ型Ｔｉ合金であり、この合金との性能の差異を明確にすることが必要だと判断したからである。
そして、様々な歪値まで試験片を引張って、各歪値における強度を記録し、さらに除荷後に永久歪が生じているかを調査した。その結果得られた弾性限強度（除荷後に元の寸法に戻る限界まで引張った時の強度）、弾性限歪ε１（除荷後に元の寸法に戻る限界の歪）及び応力−歪曲線から、それぞれの合金について蓄積できる弾性エネルギーを求めた。弾性エネルギーは、応力−歪曲線と縦軸（歪＝０）、横軸（応力＝０）、歪＝ε１で囲まれる面積から求めることができる。なお、弾性エネルギーは、従来合金である２５合金のエネルギーを１００として、整数比で示した。
この値は、それぞれの合金が、弾性変形の範囲内で蓄積できるエネルギーの大小を示すものであり、この値が大きいほど、フェース部に用いた際により大きくたわんでも、元の形状に戻ることを意味し、飛距離の上昇に貢献できるクラブの製造が可能となるからである。結果を表２に示す。

表２から明らかなように、本発明合金は、従来合金２５に比べ２倍程度の弾性エネルギーを蓄積できることが明らかとなった。従って、本発明合金をゴルフクラブに適用した場合には、このエネルギーをボールを跳ね返す復元力として有効利用できるように、適切な設計をすることによって、飛距離の優れたクラブの製造を可能とすることが期待できる。
なお、本発明合金を適用しうるゴルフクラブヘッドの構造の１例を図２、図３に示す。
図２に示すものは金属製ウッド型のクラブヘッド４であり、一般的に、ゴルフボールを捕捉するフェース部４１と、クラウン部、ソール部、サイド部を備えた本体部分４２とを組み合わせて構成される。
図３に示すものはアイアン型のクラブヘッド５であり、全体を１つの合金で作製したものもあるが、フェース部５１と、その周囲の部分５２を別合金で作製して組み合わせたものが本発明の適用例である。Next, features of the present invention will be clarified by examples. Table 1 shows chemical components of the test materials used as examples. Of these, No. Nos. 1 to 11 are alloys within the scope of the present invention. 1 to 3 are alloys corresponding to claim 1, No. 4 to 11 are alloys corresponding to claim 2. No. Alloys 12 to 24 are comparative alloys in which any component content is outside the scope of the present invention. The 25 and 26 alloys are Ti-15V-3Cr-3Sn-3Al alloy and Ti-11.5Mo-6Zr-4.5Sn alloy (also called βIII alloy), which are conventional alloys, respectively. This alloy is known to have the highest strength.

These test materials are 10 kg ingot (diameter 120 mm) melted by vacuum double arc melting into a wire rod having a diameter of 6 mm by hot forging and hot rolling, and the surface oxide layer is removed by pickling. Furthermore, it prepared by implementing cold rolling which cross-sectional reduction rate will be 50%, without performing intermediate annealing. And the tensile strength and Young's modulus were measured using the obtained test material.
The Young's modulus was obtained from the slope of the curve within the elastic range by attaching a strain gauge to the tensile test piece, measuring the stress-strain curve during the tensile test.
The cold workability is indicated by ○ when cold rolling with a reduction in area of 50% at the time of preparation of the test material can be performed normally, and by × when cracking occurs and rolling cannot be performed normally. It was. The results are shown in Table 1 described above.
As is apparent from Table 1, No. 1 is an alloy of the present invention. All the alloys 1 to 11 can normally be cold rolled with a cross-section reduction rate of 50%, exhibit a low Young's modulus of 80 GPa or less and a high tensile strength of 1000 MPa or more, and are important when applied to a spectacle frame. It can be seen that the spring characteristics are very excellent.
On the other hand, No. which is a comparative alloy. Since the content of any element of the 12-24 alloy does not satisfy the conditions of the present invention, any of Young's modulus, tensile strength, and cold workability is inferior to the alloy of the present invention. Specifically, no. In Alloys 12 to 23, since the elements indicated by * in Table 1 are out of the range, the Young's modulus is inferior. The alloys Nos. 16 and 18 have a low content of Al and Zr, which are elements having a large effect on improving the strength. Since Alloy 24 has a high O content, cold workability is greatly reduced and cracking occurs during cold rolling.
In addition, No. which is a conventional alloy. Alloys 25 and 26 are the alloys with the highest strength among the conventional alloys, and show excellent values for strength, but have high Young's modulus and cannot achieve both high strength and low rigidity. It is.
From the above results, it has been clarified that the alloy of the present invention has excellent characteristics. Thus, an eyeglass frame as shown in FIG. 1 was actually manufactured using the alloy of the present invention. In the figure, 1 is a temple portion, 2 is a rim portion, and 3 is a bridge portion. Of these, one temple part is the part that has the greatest influence on wearability and fit, so one type of temple part, rim part, and bridge part are all pure titanium (Young's modulus 100 GPa, tensile strength 600 MPa) No. 1 in which only the temple portion is shown in Table 1 is manufactured. An eyeglass frame made of the same pure titanium as described above was manufactured using an alloy corresponding to No. 1. The rim part and the bridge part were manufactured to have the same dimensions, and the temple part was changed in thickness so that the breaking load by tension was the same, and the length was the same. As a result of measuring the weight after manufacturing, the glass frame made from pure titanium alone was 5.5 g, whereas the glass frame using the alloy of the present invention for the temple portion realized a weight reduction of 4.5 g and 1 g. I was able to.
This is because of the difference in the alloy used for the prototype glasses frame, but the wearability and fit may vary depending on the individual, and it is difficult to evaluate clearly with numerical values. 5 levels of wearability and fit were selected (assessment was evaluated as 5, 4, 3, 2, 1 for each of 5, 4, 3, 2, 1), and the average score was evaluated. . As a result, the average number of glass frames manufactured using only the conventional alloy was 3.2 points, whereas the average size of the glass frames using the alloy of the present invention was 4.4 points. This is presumed to be due to the improved fit because the Young's modulus is reduced and the strength is increased, and the degree of freedom in adjusting the distance between the temples is increased when wearing glasses. The
Next, another embodiment showing that a club having an excellent flight distance can be manufactured when the Ti alloy of the present invention is used for the face portion of a golf club head will be described. In the experiment, among the match money used in the above examples, 1, 10, 11 alloy, 25 alloy which is a conventional alloy (15-3-3-3 alloy) is selected as the alloy of the present invention, and the tensile test described above is performed. Tensile test specimens were prepared in the same manner.
Here, as a conventional alloy, the 25-alloy 15-3-3 alloy was selected together with the 15-5-3 alloy (15% Mo-5% Zr-3% Al-77% Ti), It is a β-type Ti alloy that is the most commonly used for the face part of golf club heads among the conventionally known Ti alloys, and it is necessary to clarify the difference in performance from this alloy. Because.
Then, the test piece was pulled to various strain values, the strength at each strain value was recorded, and it was further investigated whether permanent strain was generated after unloading. From the resulting elastic limit strength (strength when pulled to the limit to return to the original dimension after unloading), elastic limit strain ε1 (limit strain to return to the original dimension after unloading) and the stress-strain curve, The elastic energy that can be accumulated for each alloy was determined. The elastic energy can be obtained from an area surrounded by a stress-strain curve, a vertical axis (strain = 0), a horizontal axis (stress = 0), and strain = ε1. The elastic energy is expressed as an integer ratio with the energy of 25 alloy, which is a conventional alloy, being 100.
This value indicates the amount of energy that each alloy can store within the range of elastic deformation, and the larger this value, the more it returns to its original shape even when it is used for the face part. This means that it is possible to manufacture a club that can contribute to an increase in flight distance. The results are shown in Table 2.

As is apparent from Table 2, the alloy of the present invention can accumulate about twice as much elastic energy as the conventional alloy 25. Therefore, when the alloy of the present invention is applied to a golf club, it is possible to manufacture a club having an excellent flight distance by appropriate design so that this energy can be effectively used as a restoring force to rebound the ball. I can expect that.
An example of a golf club head structure to which the alloy of the present invention can be applied is shown in FIGS.
FIG. 2 shows a metal wood-type club head 4 that is generally configured by combining a face portion 41 for capturing a golf ball and a main body portion 42 having a crown portion, a sole portion, and a side portion. Is done.
FIG. 3 shows an iron-type club head 5, and the whole is made of one alloy, but the face portion 51 and the surrounding portion 52 are made of another alloy and combined. It is an application example of the invention.

As is clear from the above results, the alloy of the present invention has workability that can be processed into a wire by cold working, so that high strength by work hardening can be easily achieved, and aging treatment A tensile strength of 1000 MPa or more can be obtained without depending on the above. In addition, it can achieve high strength and low Young's modulus of 80 GPa or less, and it has a Young's modulus close to human bones as well as many kinds of portable goods and accessories. In particular, when applied to a spectacle frame, it is possible to greatly improve the wearability and fit.
Further, the alloy of the present invention can store more elastic energy than the conventional alloy, so when used in the face part of a golf club head, it can give a larger repulsive force to the ball and has an excellent flight distance. Clubs can be manufactured.

Claims (6)

Nb: 1 to 20%, V: 10 to 25%, Al: 2 to 5%, Zr: more than 3% and 10% or less, O: 0.30% or less, with the balance being Ti and inevitable A low-rigidity, high-strength titanium alloy with excellent cold workability, characterized by consisting of mechanical impurity elements. In Claim 1, it replaces with a part of said Ti, Furthermore, 1 type (s) or 2 or more types are contained among Sn, Ta, W, Mo, Cr, The content is the mass%, These are 25 in total. % Low-rigidity and high-strength titanium alloy excellent in cold workability, characterized in that Sn is 5% or less, and the total of Ta, W, Mo and Cr is 20% or less. In a glasses frame formed by using a cold-worked wire made of a titanium alloy as at least a part of the material,
The titanium alloy contains Nb: 1 to 20%, V: 10 to 25%, Al: 2 to 5%, Zr: more than 3% and 10% or less, and O: 0.30% or less in mass%. A spectacle frame characterized in that the balance is made of Ti and inevitable impurity elements. In Claim 3, the said titanium alloy contains 1 type, or 2 or more types among Sn, Ta, W, Mo, and Cr further, replacing with a part of said Ti, The content is the mass%. A spectacle frame characterized in that the total is 25% or less, Sn is 5% or less, and the total of Ta, W, Mo and Cr is 20% or less. In a golf club head using a cold-worked plate material made of a titanium alloy for the face part,
The titanium alloy contains Nb: 1 to 20%, V: 10 to 25%, Al: 2 to 5%, Zr: more than 3% and 10% or less, and O: 0.30% or less in mass%. A golf club head comprising a balance of Ti and inevitable impurity elements. In claim 5, the titanium alloy further contains one or more of Sn, Ta, W, Mo, Cr instead of a part of the Ti, and the content thereof is expressed by mass%. A golf club head characterized by being 25% or less in total, Sn being 5% or less, and the total of Ta, W, Mo and Cr being 20% or less.

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