主权项 |
1. A golf club head comprising:
at least one ball-striking face, wherein the ball-striking face comprises a titanium alloy with an average grain size measuring less than 1 μm in the longest dimension, the golf club having a coefficient of restitution of about 0.847 or more when a ball impacts the ball-striking face, wherein the titanium alloy has a yield strength of about 860 MPa to about 1100 MPa, and wherein the titanium alloy comprises, about 5.5% to about 6.75% aluminum, about 1.8% to about 2.2% tin, about 3.6% to about 4.4% zirconium, molybdenum, and the balance titanium and incidental elements and impurities. |