Golf Club Head Alloy

Abstract

A golf club head alloy includes 5.5-8 parts by weight of aluminum, 1.7-3.3 parts by weight of molybdenum, 1.7-2.3 parts by weight of vanadium, and at least one of not greater than 2 parts by weight and greater than 0 parts by weight of chromium, not greater than 0.35 parts by weight and greater than 0 parts by weight of silicon, 0.15-1.3 parts by weight of iron, 0.05-0.2 parts by weight of boron, and 2.5-3.5 parts by weight of tin, with the balance being titanium.

Claims

1. A golf club head alloy comprising 5.5-8 parts by weight of aluminum, 1.7-3.3 parts by weight of molybdenum, 1.7-2.3 parts by weight of vanadium, and at least one of not greater than 2 parts by weight and greater than 0 parts by weight of chromium, not greater than 0.35 parts by weight and greater than 0 parts by weight of silicon, 0.15-1.3 parts by weight of iron, 0.05-0.2 parts by weight of boron, and 2.5-3.5 parts by weight of tin, with the balance being titanium.

2. The golf club head alloy as claimed in claim 1, wherein the golf club head alloy comprises 7-8 parts by weight of aluminum.

3. The golf club head alloy as claimed in claim 1, wherein the golf club head alloy comprises 1.7-2.3 parts by weight of molybdenum.

4. The golf club head alloy as claimed in claim 1, wherein the golf club head alloy comprises 1.4-2 parts by weight of chromium.

5. The golf club head alloy as claimed in claim 1, wherein the golf club head alloy comprises 0.25-0.35 parts by weight of silicon.

6. The golf club head alloy as claimed in claim 1, wherein the golf club head alloy comprises 0.7-1.3 parts by weight of iron.

7. The golf club head alloy as claimed in claim 1, wherein the golf club head alloy comprises 0.05-0.2 parts by weight of boron.

8. The golf club head alloy as claimed in claim 1, wherein the golf club head alloy comprises 2.7-3.2 parts by weight of tin.

9. The golf club head alloy as claimed in claim 1, wherein the golf club head alloy comprises 7.5 parts by weight of aluminum, 2 parts by weight of molybdenum, 2 parts by weight of vanadium, and 1.7 parts by weight of chromium, 0.3 parts by weight of silicon, 1 part by weight of iron, with the balance being titanium.

10. The golf club head alloy as claimed in claim 1, wherein the golf club head alloy comprises 7.5 parts by weight of aluminum, 3 parts by weight of molybdenum, 2 parts by weight of vanadium, 1.5 parts by weight of chromium, 0.25 parts by weight of iron, 0.1 parts by weight of boron, with the balance being titanium.

11. The golf club head alloy as claimed in claim 1, wherein the golf club head alloy comprises 6 parts by weight of aluminum, 2 parts by weight of molybdenum, 2 parts by weight of vanadium, 0.2 parts by weight of boron, 3 parts by weight of tin, with the balance being titanium.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will become more fully understood from the detailed description given hereinafter and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:

[0021] FIG. 1 is an alloy phase diagram of a second embodiment according to the present invention.

[0022] FIG. 2 is an alloy phase diagram of a third embodiment according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0023] A preferred embodiment of a golf club head alloy according to the present invention includes aluminum (Al), molybdenum (Mo), vanadium (V), and at least one of chromium (Cr), silicon (Si), iron (Fe), boron (B), and tin (Si), with the balance being titanium (Ti). Therefore, the golf club head alloy can form a titanium alloy. The golf club head alloy may form a club head body or a striking faceplate of a golf club head. The present invention is not limited in this regard.

[0024] Specifically, the golf club head alloy includes 5.5-8 parts by weight of aluminum, 1.7-3.3 parts by weight of molybdenum, 1.7-2.3 parts by weight of vanadium, and at least one of not greater than 2 parts by weight and greater than 0 parts by weight of chromium, not greater than 0.35 parts by weight and greater than 0 parts by weight of silicon, 0.15-1.3 parts by weight of iron, 0.05-0.2 parts by weight of boron, and 2.5-3.5 parts by weight of tin, with the balance being titanium. Chromium, silicon, molybdenum, and vanadium enable the club head formed of the golf club head alloy to possess predetermined strength. Furthermore, molybdenum and vanadium provide the golf club head with better plasticity to benefit the processing operation. Furthermore, in another embodiment, the golf club head alloy may include 7-8 parts by weight of aluminum, 1.7-2.3 parts by weight of molybdenum, 1.7-2.3 parts by weight of vanadium, and 1.4-2 parts by weight of chromium, 0.25-0.35 parts by weight of silicon, 0.7-1.3 parts by weight of iron, with the balance being titanium.

[0025] Specifically, aluminum metal can stabilize α phase of titanium alloy to increase the formation rate of the club head made of the golf club head alloy. Nevertheless, excessive amount of aluminum causes embrittlement of the club head, whereas insufficient aluminum results in poor formation rate. Thus, in another embodiment, the golf club head may include 7.5 parts by weight of aluminum to have a better formation rate and a better strength when using the golf club head alloy to form a club head.

[0026] Molybdenum can stabilize β phase of the titanium alloy. Adding molybdenum into the golf club head alloy can enhance the tensile strength of the club head made of the golf club head alloy, such that depression of the club head is difficult to occur after hitting a golf ball. Furthermore, in another embodiment, the golf club head alloy may include 2 parts by weight of molybdenum to further enhance the tensile strength of the club head after formation while providing the club head with a better elongation.

[0027] Vanadium is the isomorphous element of β phase stabilizing element, and vanadium has a better solid solubility in β phase. Namely, the stability of lattices can be maintained after vanadium dissolves into the alloy lattices. Thus, adding vanadium into the golf club head alloy can increase the strength of the club head. Nevertheless, excessive amount of vanadium causes reduction in the formation rate of the club head, whereas insufficient vanadium results in poor mechanical strength. Therefore, in another embodiment, the golf club head may include 2 parts by weight of vanadium to provide a better formation rate and a better strength when using the golf club head alloy to produce a club head body or a striking faceplate. Furthermore, the golf club head alloy may include 1.7 parts by weight of chromium and 0.3 parts by weight of silicon to provide the golf club head with a better strength.

[0028] It is worth noting that atoms in the alloy crystal may have dislocated movement (which is called “dislocation”) in the crystalline lattices due to local irregular arrangement, and the dislocation is regarded as a flaw in the alloy which will cause deformation of metal. The metal can be hardened if the dislocation is avoided. Iron atoms can hinder the dislocation. Thus, addition of iron can enhance the tensile strength of the alloy. In another embodiment, the golf club head alloy may include 1 part by weight of iron to provide a better strength when using the golf club head alloy to produce the club head body or the striking faceplate.

[0029] Accordingly, after a worker uses the above golf club head alloy to form a golf club head, the golf club head can have a better mechanical strength and is better than a golf club head made of the conventional titanium alloy. Furthermore, the golf club head alloy has a better elongation and is, thus, easy to form. Therefore. the golf club alloy may have a better formation rate.

[0030] To prove the golf club head alloy composition according to the present invention indeed possesses good strength, measurements of the mechanical properties of striking faceplates formed by hot rolling the conventional titanium (group 1 of Table 1) and the titanium alloy (group 2 of Table 1) of an embodiment of the present invention to form a plate and then undergoing hot press-forging at 830° C. for 6 minutes are carried out, and the measurement result is shown in Table 2.

TABLE-US-00001 Composition ratio (parts by weight) of golf club head alloy of each group of this test group Al Mo V Cr Si Fe Ti 1 7 2.2 0.8 1.4 0.25 - balance 2 7.5 2 2 1.7 0.3 1 balance

TABLE-US-00002 Mechanical properties of striking faceplate formed of each group group Tensile strength (ksi) Yield strength (ksi) Young’s Modulus (GPa) 1 173.0 164.9 130.8 2 182.7 181.3 148.9

[0031] As can be seen from the above test result, the tensile strength and the yield strength of the striking faceplate (group 2) made of the golf club head alloy according to the present invention are higher than those of the striking faceplate made of the conventional titanium alloy (group 1). Furthermore, in comparison with the conventional titanium alloy, with provision of higher amount of vanadium in the golf club head alloy according to the present invention, the strength of the golf club head made of the golf club head alloy according to the present invention can be increased.

[0032] Furthermore, addition of boron can effectively thin the crystalline grains of the titanium alloy. This can avoid decrease in the mechanical properties caused by coarse crystalline grains when forming the golf club head body or the striking faceplate. Thus, the second embodiment of the golf club head alloy according to the present invention may include 5.5-8 parts by weight of aluminum, 1.7-3.3 parts by weight of molybdenum, 1.7-2.3 parts by weight of vanadium, not greater than 2 parts by weight and greater than 0 parts by weight of chromium, not greater than 0.35 parts by weight and greater than 0 parts by weight of silicon, 0.25-1.3 parts by weight of iron, 0.05-0.2 parts by weight of boron, with the balance being titanium. Specifically, the golf club head alloy may include 7.5 parts by weight of aluminum, 3 parts by weight of molybdenum, 2 parts by weight of vanadium, 1.5 parts by weight of chromium, 0.25 parts by weight of iron, 0.1 parts by weight of boron, with the balance being titanium.

[0033] Furthermore, measurements of mechanical properties of plates formed by hot rolling at 700° C. on the titanium alloy (group 2) of the first embodiment according to the present invention and the titanium alloy (group 3) of the second embodiment according to the present invention are carried out, and the result is shown in Table 4.

TABLE-US-00003 Composition ratio (parts by weight) of golf club head alloy of each group of this test group Al Mo V Cr Si Fe B Ti 2 7.5 2 2 1.7 0.3 1 - balance 3 7.5 3 2 1.5 - 0.25 0.1 balance

TABLE-US-00004 Mechanical properties of golf club head alloy formed of each group after hot rolling group Tensile strength (ksi) Yield strength (ksi) Elongation (%) 2 204.0 200.4 1.7 3 221.9 200.3 6

[0034] As can be seen from the above test result, in comparison with the first embodiment (group 2) of the golf club head alloy according to the present invention, the tensile strength and the elongation of the second embodiment (group 3) of the golf club head alloy according to the present invention can be further enhanced after addition of boron. Furthermore, with reference to FIG. 1 showing the phase diagram of the second embodiment of the golf club head alloy according to the present invention, carrying out the hot rolling at 700° C. enables the alloy of the second embodiment to have the maximum ratio of α phase (about 79%) and β phase in a proper ratio. α phase can provide the alloy with strength, whereas β phase can provide the alloy with ductility. Accordingly, the alloy composition of the second embodiment of the golf club head alloy according to the present invention can have better elongation under certain processing conditions while maintaining the strength.

[0035] Furthermore, addition of tin (Sn) into the titanium alloy can enhance formation of Ti.sub.3Al phase. Presence of the Ti.sub.3Al phase is advantageous to increase the strength. Namely, the golf club head alloy can have good strength with precipitation of Ti.sub.3Al phase. Therefore, in the third embodiment, the golf club head alloy according to the present invention may include 5.5-6.5 parts by weight of aluminum, 1.7-2.3 parts by weight of molybdenum, 1.7-2.3 parts by weight of vanadium, 0.05-0.2 parts by weight of boron, 2.7-3.2 parts by weight of tin, with the balance being titanium. Specifically, the golf club head alloy may include 6 parts by weight of aluminum, 2 parts by weight of molybdenum, 2 parts by weight of vanadium, 3 parts by weight of tin, 0.2 parts by weight of boron, with the balance being titanium. It is worth noting that the content of aluminum is reduced to 5.5-6.5 parts by weight, which can increase precipitation of Ti.sub.3Al phase to further increase the strength of the alloy.

[0036] Furthermore, with the alloy composition of the third embodiment of the golf club head alloy according to the present invention, after forming a plate by hot rolling, the tensile strength of the plate is 210.7 ksi, and the elongation of the plate is 6.5%, which are higher than those of the alloy composition of the first embodiment of the golf club head alloy according to the present invention. This shows that, in comparison with the first embodiment, the alloy composition of the third embodiment of the golf club head alloy according to the present invention can further increase the tensile strength and the elongation. Furthermore, with reference to FIG. 2 showing the phase diagram of the third embodiment of the golf club head alloy according to the present invention, hot rolling enables the alloy of the second embodiment to have the maximum ratio of α phase (about 93%) and β phase in a proper ratio. α phase can provide the alloy with strength, whereas β phase can provide the alloy with ductility. Accordingly, the alloy composition of the third embodiment of the golf club head alloy according to the present invention can have better elongation under certain processing conditions while maintaining the strength.

[0037] In view of the foregoing, in the golf club head alloy according to the present invention, by certain composition ratio, particularly having a higher amount of vanadium in comparison with the conventional titanium alloy (Table 1, group 1), good mechanical properties (tensile strength, yield strength, and elongation) can be provided when using the golf club head alloy to form a club head body or a striking faceplate. Furthermore, addition of boron can thin the crystalline grains of the golf club head alloy. This can avoid decrease in the mechanical properties caused by coarse crystalline grains when forming the club head body or the striking faceplate. Furthermore, addition of tin can enhance formation of Ti.sub.3Al phase in the golf club head alloy, further increasing the strength of the golf club head alloy.

[0038] Although the invention has been described in detail with reference to its presently preferable embodiments, it will be understood by one of ordinary skill in the art that various modifications can be made without departing from the spirit and the scope of the invention, as set forth in the appended claims. Furthermore, in a case that several of the above embodiments can be combined, the present invention includes the implementation of any combination.