Weight member for a golf club head

Abstract

A weight member for a golf club head is made of a WMoNi alloy by powder metallurgy or a precision casting process. The WMoNi alloy includes tungsten 1-35 wt %, molybdenum 4-55 wt %, and nickel 25-95 wt %, and has a specific gravity ranging between 8.6 and 13.3. Molybdenum increases the density of the weight member and improves the rust-resisting property of the weight member. The tungsten, molybdenum, and nickel provide a uniform metallographic phase. Uniformity of polishing of the weight member is thus improved.

Description

CROSS REFERENCE TO RELATED APPLICATION [0001] This application is a continuation-in-part application of U.S. patent Ser. No. 10 / 673,418, filed on Sep. 30, 2003.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a weight member for a golf club head. In particular, the present invention relates to a weight member for a golf club head made of WmoNi alloy having a specific gravity ranging between 8.6 and 13.3. [0004] 2. Description of Related Art [0005] A conventional weight member for a golf club head is made by powder metallurgy in which metal powders of high density and high rigidity such as tungsten having a density of 19.30 g / cm3, iron having a density of 7.8 g / cm3, and nickel having a density of 8.9 g / cm3 are pressed to form a predetermined shape of the metal powders. Then the shaped metal powders are sintered to form a WFeNi weight member for a golf club head. Although the powder metallurgy is widely used, there exists several dis...

AI Technical Summary

Benefits of technology

[0009] An object of the present invention is to provide a weight member for a golf club head, wherein molybdenum is added to increase the density of the weight member and to improve the rust-resisting property of the weight member. However, molybdenum has a density greater than that of iron, and the rust-resisting property more excellent than that of iron.

[0010] Another object of the present invention is to provide a weight member for a golf club head, wherein the weight member is made of a WMoNi alloy to improve the uniformity of the polishing and the appearance of the weight member. SUMMARY OF THE INVENTION

[0011] To achieve the aforementioned objects, the present invention provides a weight member for a golf club head that is made of a WMoNi alloy by powder metallurgy or a precision casting process. The WMoNi alloy includes tungsten 1-35 wt %, molybdenum 4-55 wt %, and nickel 25-95 wt %, and has a specific gravity ranging between 8.6 and 13.3. Molybdenum increases the density of the weight member and improves the rust-resisting property of the weight member. The tungsten, molybdenum, and nickel provide a uniform metallographic phase. Uniformity of polishing of the weight member is thus improved.

Problems solved by technology

Although the powder metallurgy is widely used, there exists several disadvantages, including high cost for molds, low stretchability of products, long processing time, aptness to thermal expansion / shrinkage, and difficulty in forming delicate patterns, letters, serial number, trade names, etc.

However, if the mixture ratio of the nickel, iron, and tungsten was not properly controlled, a pearlite structure was precipitated in a base of a γ (iron, nickel) phase of the WFeNi alloy, deteriorating the rust-resisting property of the weight member.

Further, such γ (iron, nickel) phase of the WFeNi alloy is apt to result in cracks while welding the weight member to the golf club head body.

Thus, it is difficult to control the processing conditions.

In conclusion, since the conventional weight member made of WFeNi alloy contains iron such that the weight member has poor characteristics in the metallographical composition, rust-resisting property, and welding.

The assembling procedure, appearance, bonding strength, manufacturing tolerance, and life of the golf club product are adversely affected.

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