Enhanced golf club performance via friction stir processing

Abstract

Friction stir processing (FSP) provides a hardened golf club face that more efficiently transfers momentum between the golf club and the ball, increasing the launch velocity so as to provide increased loft (for a given distance traveled by the ball). The FSP hardened face is also more resistant to wear so that the golf club provides more consistent performance and lasts longer. A practice club having a friction stir processed sweet spot on the face may enable the golfer to feel whether the ball has been hit by the sweet spot.

1 . A method for improving the performance of a golf club, comprising the steps of: 
 fabricating a golf club head having a face;    friction stir processing a predetermined area of the surface of the golf club face; and    re-surfacing at least the predetermined area subjected to friction stir processing so as to provide a desired surface topology.    
     
     
         2 . The method of  claim 1 , wherein the golf club head comprises a metal selected from the group consisting of aluminum, titanium, nickel, copper, iron, and alloys thereof.  
     
     
         3 . The method of  claim 1 , wherein said step of fabricating includes a step of casting or forging.  
     
     
         4 . The method of  claim 1 , wherein said step of friction stir processing is performed using a FSP tool rotating at a rate between 150 and 2000 rotations per minute.  
     
     
         5 . The method of  claim 1 , wherein said step of friction stir processing is performed using a FSP tool moved along the workpiece surface at a rate of 50 to 7000 mm/minute.  
     
     
         6 . The method of  claim 1 , wherein said step of re-surfacing includes a step of milling.  
     
     
         7 . The method of  claim 1 , wherein the desired surface topology includes at least one groove.  
     
     
         8 . A method for improving the performance of a golf club, comprising the steps of: 
 friction stir processing a predetermined area of the surface of a metallic workpiece; and    fabricating a golf club head having a face which includes the predetermined area.    
     
     
         9 . The method of  claim 8 , wherein the metallic workpiece comprises a metal selected from the group consisting of aluminum, titanium, nickel, copper, iron, and alloys thereof.  
     
     
         10 . The method of  claim 8 , wherein the metallic workpiece has a shape selected from the group consisting of strip, plate and block.  
     
     
         11 . The method of  claim 8 , wherein said step of fabricating includes a step of forging.  
     
     
         12 . The method of  claim 8 , wherein said step of friction stir processing is performed using a FSP tool rotating at a rate between 150 and 2000 rotations per minute.  
     
     
         13 . The method of  claim 8 , wherein said step of friction stir processing is performed using a FSP tool moved along the workpiece surface at a rate of 50 to 7000 mm/minute.  
     
     
         14 . The method of  claim 8 , further comprising the step of: 
 re-surfacing at least the predetermined area subjected to friction stir processing so as to provide a desired surface topology.    
     
     
         15 . The method of  claim 14 , wherein the step of re-surfacing is performed before the step of fabricating.  
     
     
         16 . The method of  claim 14 , wherein the step of re-surfacing is performed after the step of fabricating.  
     
     
         17 . The method of  claim 14 , wherein the desired surface topology includes at least one groove.  
     
     
         18 . A golf club with improved performance, comprising a head with a face, said face comprising friction stir processed metal.  
     
     
         19 . The golf club of  claim 18 , wherein said friction stir processed metal is selected from the group consisting of aluminum, titanium, nickel, copper, iron, and alloys thereof.