Method for manufacturing a golf club head

Abstract

A method for manufacturing a golf club head includes providing a club head body produced by electric smelting an alloy base material including 0.04-0.07 wt % of carbon, 0.5-1.0 wt % of manganese, 0.5-1.0 wt % of silicon, less than 0.04 wt % of phosphorus, less than 0.03 wt % of sulfur, 15-17.7 wt % of chromium, 3.6-5.1 wt % of nickel, 2.8-3.5 wt % of copper, with the rest being iron and inevitable impurities. A solid solution treatment is proceeded at 1020-1080 C. for 80-100 minutes to form austenite and martensite in the club head body. A deep cooling treatment is proceeded between 120 C. and 80 C. for 7-9 hours to turn the austenite in the club head body into martensite. An aging treatment is proceeded on the club head body at 460-500 C. for 210-270 minutes to provide a hardness of HRC 36-46. A hosel is heated with high frequency waves at 900-1000 C. to posses a hardness lower than HRC 20.

Claims

1. A method for manufacturing a golf club head, comprising: providing a club head body including a hosel, wherein the club head body is produced by electric smelting an alloy base material including 0.04-0.07 wt % of carbon, 0.5-1.0 wt % of manganese, 0.5-1.0 wt % of silicon, less than 0.04 wt % of phosphorus, less than 0.03 wt % of sulfur, 15-17.7 wt % of chromium, 3.6-5.1 wt % of nickel, 2.8-3.5 wt % of copper, with the rest being iron and inevitable impurities; proceeding with a solid solution treatment on the club head body at 1020-1080 C. for 80-100 minutes to form austenite and martensite in the club head body; proceeding with a deep cooling treatment on the club head body at a temperature in a range between 120 C. and 80 C. for 7-9 hours to turn the austenite in the club head body into martensite; proceeding with an aging treatment on the club head body at 460-500 C. for 210-270 minutes to provide the club head body with a hardness of HRC 36-46; and heating the hosel of the club head body at 900-1000 C. to provide the hosel with a hardness lower than HRC 20.

2. The method for manufacturing a golf club head as claimed in claim 1, wherein the alloy base material includes 16.4-16.7 wt % of chromium and 4.7-5.1 wt % of nickel.

3. The method for manufacturing a golf club head as claimed in claim 1, wherein the hosel includes a hole having an opening and a bottom spaced from the opening by 30-33 mm.

4. The method for manufacturing a golf club head as claimed in claim 3, wherein heating the hosel is conducted within an area having a spacing not larger than 7.5 mm to the bottom of the hole.

5. The method for manufacturing a golf club head as claimed in claim 1, wherein a nickel layer of 18-25 m is electroplated on a surface of the club head body after the aging treatment, and wherein the hosel of the club head body is then heated to adjust an angle of the hosel.

6. The method for manufacturing a golf club head as claimed in claim 5, wherein a chromium layer of 3-8 m is electroplated on a surface of the nickel layer, and wherein the hosel of the club head body is then heated to adjust an angle of the hosel.

7. The method for manufacturing a golf club head as claimed in claim 1, further comprising adjusting an angle of the hosel after heating the hosel of the club head body.

8. The method for manufacturing a golf club head as claimed in claim 1, wherein heating includes heating the hosel at 900-1000 C. for 20-30 seconds.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a diagrammatic view illustrating an area of a hosel of a club head body to be heated by high frequency waves for subsequent angle adjustment of the hosel by a method according to the present invention.

(2) FIG. 2a is a result of a metallographic analysis on a metallographic structure of group A1 in test A.

(3) FIG. 2b is a result of a metallographic analysis on a metallographic structure of group A2 in test A.

DETAILED DESCRIPTION

(4) A method for manufacturing a golf club head according to the present invention includes preparing a club head body 1 that is subject to the steps including a solid solution treatment, a deep cooling treatment, an aging treatment, and a high frequency wave heating treatment to obtain a golf club head fulfilling the user needs.

(5) Specifically, a club head body 1 having a hosel 11 (see FIG. 1) is provided. The club head body 1 is produced by electric smelting an alloy base material including 0.04-0.07 wt % of carbon, 0.5-1.0 wt % of manganese, 0.5-1.0 wt % of silicon, less than 0.04 wt % of phosphorus, less than 0.03 wt % of sulfur, 15-17.7 wt % of chromium, 3.6-5.1 wt % of nickel, 2.8-3.5 wt % of copper, with the rest being iron and inevitable impurities. Preferably, the alloy base material includes 16.4-16.7 wt % of chromium and 4.7-5.1 wt % of nickel. Through adjustment of the contents of chromium and nickel, the hardness, the strength, and the torque of the resultant club head body 1 can fulfill the needs while providing the club head body 1 with enhanced angle adjustability.

(6) The solid solution treatment is conducted on the club head body 1 at 1020-1080 C. for 80-100 minutes, such that a portion of the metallographic structure of the club head body 1 can dissolve in the solid solution. Thus, the metallographic structure in the club head body 1 includes austenite and martensite.

(7) After the solid solution treatment, the deep cooling treatment is conducted on the club head body 1 at a temperature in a range between 120 C. and 80 C. for 7-9 hours to turn the austenite in the club head body 1 into martensite. Thus, the hardness and the abrasion strength of the club head body 1 can be increased.

(8) After the deep cooling treatment, the aging treatment is conducted on the club head body 1 at 460-500 C. for 210-270 minutes, thereby precipitating and strengthening the club head body 1. Thus, the hardness of the club head body 1 is in a range of HRC 36-46.

(9) In the high frequency wave heating treatment, the hosel 11 of the club head body 1 is performed after the aging treatment. The martensite in the hosel 11 turns back into austenite to provide the hosel 11 with a hardness lower than HRC 20. In this embodiment, the hosel 11 of the club head body 1 is heated with high frequency waves at 900-1000 C. for about 20-30 seconds.

(10) With reference to FIG. 1, it is noted that the hosel 11 includes a hole 12 having an opening 121 and a bottom 122 spaced from the opening 121 by a spacing a of 30-33 mm. The high frequency wave heating on the hosel 11 is conducted within an area b having a spacing not larger than 7.5 mm to the bottom 122 of the hole 12.

(11) The club head body 1 obtained after the solid solution treatment, the deep cooling treatment, the aging treatment, and the high frequency wave heating treatment, not only has high strength but permits easy adjustment of an inclination angle of the hosel 11. Thus, the method for manufacturing a golf club head according to the present invention can further include a step of adjusting an angle of the hosel 11 after heating the hosel 11 of the club head body 1 with high frequency waves. In this case, a torque less than 80 pounds can be applied to achieve an angle adjustment of 2.

(12) To prevent the club head body 1 from rusting, a surface electroplating step can be carried out after the aging treatment. A nickel layer of 18-25 m is electroplated on a surface of the club head body 1 after the aging treatment. Since the nickel layer has a low hardness, a chromium layer of 3-8 m is preferably electroplated on a surface of the nickel layer to increase the abrasion strength and the hardness of the club head body 1 by the chromium layer.

(13) To prove the method according to the present invention can be used to manufacture a golf club head (which permits easy adjustment of the inclination angle) through the solid solution treatment, the deep cooling treatment, the aging treatment, and the high frequency wave heating treatment, experiments were carried out on club head bodies made of alloy base materials including 0.04-0.07 wt % of carbon, 0.5-1.0 wt % of manganese, 0.5-1.0 wt % of silicon, less than 0.04 wt % of phosphorus, less than 0.03 wt % of sulfur, 16.4-16.7 wt % of chromium, 4.7-5.1 wt % of nickel, 2.8-3.5 wt % of copper, with the rest being iron and inevitable impurities.

(14) (A) Change in the Metallographic Structure Before and after Deep Cooling Treatment

(15) With reference to Table 1, in this experiment, analysis of the metallographic structures of club head bodies after the solid solution treatment and before the deep cooling treatment (group A1) and club head bodies after the solid solution treatment and then the deep cooling treatment (group A2) are carried out, and the results are shown in FIG. 2a and FIG. 2b, respectively. In Table 1, O represents the treatment is carried out, and X represents the treatment is not carried out.

(16) TABLE-US-00001 TABLE 1 Processing Conditions of Each Group of Experiment Solid solution Deep cooling Group treatment treatment FIG. A1 X 2a A2 2b

(17) (B) Influence of Temperature of Deep Cooling Treatment and Aging Treatment Time

(18) With reference to FIGS. 2 and 2b, in this experiment, the processing temperatures were 80 C. and 120 C., and the processing times of the aging treatment were 1 hour and 4 hours. The hardness, the torque, the tensile strength, the yield strength, and the elongation of each group were measured.

(19) TABLE-US-00002 TABLE 2 Processing Conditions of Each Group of Experiment Deep cooling Aging Tensile Yield temperature treatment Hardness Torque strength strength Elongation Group ( C.) time (hr) (HRC) (lb) (Ksi) (Ksi) (%) B1 80 1 43.0 69.5 195.0 175.0 10.0 B2 120 1 43.2 68.4 197.0 175.0 9.94 B3 80 4 42.4 65.2 186.0 173.0 10.1 B4 120 4 42.5 66.1 190.0 176.0 10.4

(20) According to the above experiment result, the performances of the club head bodies are not much affected by the processing temperatures of the deep cooling treatments. However, when the aging treatment time is longer, the hardness and the yield strength are slightly reduced, the elongation is slightly increased, and the torque is slightly decreased. This shows that the angle adjustability of the club head bodies is improved.

(21) (C) Influence of Aging Treatment

(22) In this experiment, the solid solution treatment, the deep cooling treatment, the aging treatment, and the high frequency wave heating treatment were carried out in sequence on group C1. Furthermore, the solid solution treatment, the deep cooling treatment, the high frequency wave heating treatment, and the aging treatment were carried out on group C2. The torques for adjusting the angles of the club head bodies of each of group C1 and group C2 were measured. The average torque of group C1 is 67.3 lb. The average torque of group C2 is 82.8 lb. Apparently, the angle adjustability of the club head bodies of group C1 is better.

(23) (D) Influence of Contents of Chromium, Nickel, and their Sum on the Angle Adjustability

(24) With reference to Table 3, in this experiment, the contents of chromium and nickel and the sum of the contents of chromium and nickel in the alloy base materials were adjusted. Each alloy base material was subject to electric smelting to obtain a club head body which was, then, subject to the solid solution treatment, the deep cooling treatment, the aging treatment, and the high frequency wave heating treatment. Then, the hardness, the strength, and the torque of the club head bodies of each group were measured.

(25) TABLE-US-00003 TABLE 3 Processing Conditions of Each Group of Experiment Chromium + Hard- Chromium Nickel Nickel ness Strength Torque Group (wt %) (wt %) (wt %) (HRC) (Ksi) (lb) D1 15.36 4.21 19.57 42.0 199.0 92.4 D2 15.87 4.16 20.03 42.4 199.3 93.8 D3 15.64 4.89 20.53 42.0 191.0 80.5 D4 15.91 4.67 20.58 42.5 189.0 68.9 D5 15.94 4.65 20.59 40.6 186.6 58.0 D6 16.38 4.99 21.37 41.6 180.0 32.1

(26) According to the above experiment result, the hardness, the strength, and the torque of the club head bodies decrease when the contents of chromium and nickel increase. Furthermore, when the chromium content is less than 15.9% and the nickel content is less than 4.4%, the angle adjustability of the club head bodies is compromised. Additionally, considering the composition difference before and after the electric smelting of the alloy base materials, the alloy base materials preferably include 16.4-16.7 wt % of chromium and 4.7-5.1 wt % of nickel.

(27) (E) Cannon Shot Test

(28) With reference to Table 4, in this experiment, the contents of chromium and nickel in the alloy base materials were adjusted. Each alloy base material was subject to electric smelting to obtain a club head body which was, then, subject to the solid solution treatment, the deep cooling treatment, the aging treatment, and the high frequency wave heating treatment. Finally, a cannon shot test was carried on the striking face of each club head body to record the number of shots and breakage of the striking face.

(29) TABLE-US-00004 TABLE 4 Processing Conditions of Each Group of the Experiment Cannon Chromium Nickel Thickness shot Judg- Group (wt %) (wt %) (mm) conditions Result ment E1 15.91 4.67 2.4 48 m/s, No Pass 3000 shots breakage E2 16.38 4.99 No Pass breakage

(30) According to the above experiment result, the golf club head manufactured by the method according to the present invention can indeed fulfill the strength needs.

(31) In view of the foregoing, in the method for manufacturing a golf club head according to the present invention, the metallographic structure of the club head body 1 can be altered by the solid solution treatment, the deep cooling treatment, the aging treatment, and the high frequency wave heating treatment on the club head body 1 to increase the hardness and the abrasion strength of the club head body 1, obtaining a club head body 1 having a hardness of HRC 36-46 and including a hosel 11 with a hardness lower than HRC 20. Furthermore, since the club head body 1 is produced from an alloy base material including 0.04-0.07 wt % of carbon, 0.5-1.0 wt % of manganese, 0.5-1.0 wt % of silicon, less than 0.04 wt % of phosphorus, less than 0.03 wt % of sulfur, 15-17.7 wt % of chromium, 3.6-5.1 wt % of nickel, 2.8-3.5 wt % of copper, with the rest being iron and inevitable impurities, the club head body 1 includes high strength while permitting easy adjustment of the inclination angle.

(32) Thus since the invention disclosed herein may be embodied in other specific forms without departing from the spirit or general characteristics thereof, some of which forms have been indicated, the embodiments described herein are to be considered in all respects illustrative and not restrictive. The scope of the invention is to be indicated by the appended claims, rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.