Golf club strikeface with off-axis directional grain structure

Abstract

The golf club head described herein has a metal alloy strikeface formed from a faceplate having an off-axis directional grain structure. The directional grain structure can be formed of elongated grains. The faceplate can have a horizontal reference axis, extending in a heel to toe direction. The elongated grains can be angled in a longitudinal direction that is offset from the horizontal reference axis by an angle of between 5 and 85 degrees. The directional grain structure can be oriented from a low-heel region to a high-toe region of the strikeface. In some embodiments, the golf club head can have a relatively uniform characteristic time (CT) across the strikeface. Specifically, a CT differential across the strikeface can be between 0 and 7 μs.

What is claimed is: 
     
         1 . A golf club head comprising:
 a club head body comprising,
 a heel, 
 a toe, 
 a crown, 
 a sole, 
 a rear, and 
   a strikeface positioned adjacent the sole and the crown and opposite the rear;   wherein:   the club head further comprises a loft plane tangent to the strikeface;
 the strikeface comprises:
 a geometric center; 
 a horizontal reference axis extending from the toe to the heel within the loft plane and through the geometric center of the strikeface; 
 a faceplate; 
 the faceplate comprises a directional grain structure formed of elongated grains oriented on average in a longitudinal L direction; 
 the longitudinal L direction is angularly offset from the horizontal reference axis by an offset angle θ of between 5 and 85 degrees; and 
 the offset angle θ is measured counterclockwise from the horizontal reference axis. 
 
   
     
     
         2 . The golf club head of  claim 1 , wherein the offset angle θ is selected from the group consisting of: between 20 and 70 degrees, between 35 and 55 degrees, between 5 and 45 degrees, and between 45 and 85 degrees. 
     
     
         3 . The golf club head of  claim 1 , wherein the offset angle θ is selected from the group consisting of: 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 degrees, 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, 80 degrees, and 85 degrees. 
     
     
         4 . The golf club head of  claim 1 , wherein the faceplate comprises a titanium alloy material selected from the group consisting of: Ti-6A1-4V (or Ti 6-4), Ti-7S+(or Ti-7S, T-7S, or ST721), Ti-9S (or T-9S), Ti-9S+, HST-180, FS2S, Super-TiX 51AF, Super-TiX 51 Premium, Ti-662, Ti-8-1-1, Ti-65K, Ti-6246, and IMI 550. 
     
     
         5 . The golf club head of  claim 1 , wherein the faceplate comprises a steel material selected from the group consisting of: C300 steel, C350 steel, 455 steel, 431 steel, 475 steel, 565 steel, 17-4 stainless steel, maraging steel, Ni—Co—Cr steel alloy, AerMet 310 steel, and AerMet 340 steel. 
     
     
         6 . The golf club head of  claim 1 , wherein the elongated grains are oriented within 0 to 30 degrees of each other. 
     
     
         7 . The golf club head of  claim 1 , wherein:
 the strikeface further comprises an inner surface and an outer surface;   the strikeface further comprises a thickness measured between the inner surface and the outer surface, perpendicular to the loft plane; and   the thickness varies across the strikeface.   
     
     
         8 . The golf club head of  claim 7 , wherein:
 the strikeface further comprises a central region, a transition region surrounding the central region, and a peripheral region surrounding the transition region;   the thickness of the central region is greater than the thickness of the peripheral region; and   the thickness of the transition region varies.   
     
     
         9 . The golf club head of  claim 7 , wherein a minimum thickness of the strikeface is between 1.5 mm and 0.4 mm. 
     
     
         10 . The golf club head of  claim 7 , wherein the central region comprises an elliptical or egg-shaped boundary. 
     
     
         11 . The golf club head of  claim 1 , wherein the characteristic time (CT) of the golf club head is lower than a similar golf club head lacking a directional grain structure oriented at the offset angle θ of between 5 and 85 degrees. 
     
     
         12 . The golf club head of  claim 1 , wherein:
 the golf club head comprises a characteristic time (CT) differential of between 0 and 7 μs, and   the characteristic time differential is measured as the difference between a maximum characteristic time (CT) of the strikeface and a minimum characteristic time (CT) of the strikeface.   
     
     
         13 . The golf club head of  claim 1 , wherein:
 the faceplate further comprises a transverse T direction oriented perpendicular to the longitudinal L direction;   the faceplate comprises a longitudinal modulus of elasticity measured in the longitudinal L direction and a transverse modulus of elasticity measured in the transverse T direction; and   the longitudinal modulus of elasticity is lower than the transverse modulus of elasticity.   
     
     
         14 . The golf club head of  claim 13 , wherein:
 the longitudinal modulus of elasticity ranges between 108 GPa and 118 GPa (15.66 Mpsi and 17.11 Mpsi); and   the transverse modulus of elasticity ranges between range between 118 GPa and 146 GPa (17.11 Mpsi-21.17 Mpsi).   
     
     
         15 . The golf club head of  claim 1 , wherein:
 the offset angle θ is approximately 45 degrees; and   the modulus of elasticity taken along the horizontal reference axis is between 116 GPa and 130 GPa.   
     
     
         16 . A golf club head comprising:
 a club head body comprising,
 a heel, 
 a toe, 
 a crown, 
 a sole, 
 a rear, and 
   a strikeface positioned adjacent the sole and the crown and opposite the rear;   wherein:   the club head further comprises a loft plane tangent to the strikeface;
 the strikeface comprises:
 a geometric center; 
 a vertical reference axis extending from the crown to the sole within the loft plane and through the geometric center of the strikeface; 
 a horizontal reference axis extending from the toe to the heel within the loft plane and through the geometric center of the strikeface; 
 a high-toe region defined above the horizontal reference axis and on a toe side of the vertical reference axis; 
 a high-heel region defined above the horizontal reference axis and on a heel side of the vertical reference axis; 
 a low-toe region defined below the horizontal reference axis and on a toe side of the vertical reference axis; 
 a low-heel region defined below the horizontal reference axis and on a heel side of the vertical reference axis; and 
 a metal material with a directional grain structure that is oriented in a direction from the low-heel region to the high-toe region. 
 
   
     
     
         17 . The golf club head of  claim 16 , wherein:
 the strikeface comprises a faceplate;   the faceplate further comprises a transverse T direction oriented perpendicular to the longitudinal L direction;   the faceplate comprises a longitudinal modulus of elasticity measured in the longitudinal L direction and a transverse modulus of elasticity measured in the transverse T direction; and   the longitudinal modulus of elasticity is lower than the transverse modulus of elasticity.   
     
     
         18 . The golf club head of  claim 16 , wherein:
 the golf club head comprises a characteristic time (CT) differential of between 0 and 7 μs, and   the characteristic time differential is measured as the difference between a maximum characteristic time (CT) of the strikeface and a minimum characteristic time (CT) of the strikeface.   
     
     
         19 . The golf club head of  claim 16 , wherein the angled orientation of the directional grain structure causes a reduction in the characteristic time (CT) of the high-toe region, compared to a club head comprising a strikeface having a horizontal-oriented directional grain structure. 
     
     
         20 . The golf club head of  claim 16 , wherein the strikeface comprises a titanium alloy material selected from the group consisting of: Ti-6A1-4V (or Ti 6-4), Ti-7S+(or Ti-7S, T-7S, or ST721), Ti-9S (or T-9S), Ti-9S+, HST-180, FS2S, Super-TiX 51AF, Super-TiX 51 Premium, Ti-662, Ti-8-1-1, Ti-65K, Ti-6246, and IMI 550.