| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the durability and flying distance, and besides enhance reverberation characteristics of hitting sound by using for a face part a material composed of alpha plus beta type titanium alloy processed at a specified range of temperatures. SOLUTION: An alpha plus beta type titanium alloy is used at least for a face part of a golf club head. A temp. at the when a process is applied to the alloy sound be in a range from a temp. obtained by subtracting 100 deg.C from a beta transformation temp. to the beta (B) transformation temp. in order to obtain a two-phase mixed structure having an elongated form. Also, to obtain the two-phase mixed structure, preferably a hot process at the pressure rate of 30% or more should be applied. Accordingly, it is possible to produce a titanium-made golf club excellent in mechanical characteristics such as strength and durability, and high in reverberation characteristics of hitting soud in the frequency ranges of 4-6kHz and 8-10kHz at the time hitting a ball, leading to a deep hitting sound with the harmony of the two frequency range sounds.</p> |
