Golf club head and method of fabricating striking plate

Abstract

A golf club head including a head body and a striking plate is provided. The head body has an opening. The striking plate is disposed at the opening and has a striking surface. The striking plate includes a first crystallization phase region and at least a second crystallization phase region. The second crystallization phase region is located in the first crystallization phase region. The second crystallization phase region extends from the striking surface to an interior of the striking plate. The elastic modulus of the second crystallization phase region is smaller than that of the first crystallization phase region.

1 . A golf club head, comprising:
 a head body, having an opening; and   a striking plate, disposed at the opening and having a striking surface, wherein the striking plate comprises:
 a first crystallization phase region; and 
 at least a second crystallization phase region, located in the first crystallization phase region, wherein the second crystallization phase region extends from the striking surface to an interior of the striking plate, and the elastic modulus of the second crystallization phase region is smaller than that of the first crystallization phase region. 
   
   
   
       2 . The golf club head as claimed in  claim 1 , wherein a crystallization phase of the first crystallization phase region includes β-type or α-β-type. 
   
   
       3 . The golf club head as claimed in  claim 1 , wherein a crystallization phase of the second crystallization phase region includes α-type or α″type. 
   
   
       4 . The golf club head as claimed in  claim 1 , wherein the elastic modulus of the first crystallization phase region is larger than or equal to 100 GPa. 
   
   
       5 . The golf club head as claimed in  claim 1 , wherein an absolute value of the difference between the elastic modulus of the first crystallization phase region and the second crystallization phase region is larger than or equal to 5 GPa and smaller than or equal to 10 GPa. 
   
   
       6 . The golf club head as claimed in  claim 1 , wherein the striking plate is made of Ti alloy. 
   
   
       7 . A method of fabricating the striking plate, applicable for a golf club head, comprising:
 providing a plate body, wherein a crystallization phase of the plate body is a first crystallization phase;   heating a part of the plate body; and   quenching the heated part of the plate body to transform the crystallization phase of the part of the plate body into a second crystallization phase.   
   
   
       8 . The method of fabricating the striking plate as claimed in  claim 7 , wherein the step of heating the part of the plate body is achieved by irradiating the plate body with a high-energy laser beam. 
   
   
       9 . The method of fabricating the striking plate as claimed in  claim 7 , wherein the step of heating the part of the plate body is achieved by irradiating the plate body with an electron beam. 
   
   
       10 . The method of fabricating the striking plate as claimed in  claim 7 , wherein the step of quenching the heated part of the plate body is achieved by water cooling, air cooling, or furnace cooling. 
   
   
       11 . The method of fabricating the striking plate as claimed in  claim 7 , wherein a cooling rate of quenching the heated part of the plate body is larger than or equal to 10° C. per second. 
   
   
       12 . The method of fabricating the striking plate as claimed in  claim 7 , wherein the first crystallization phase comprises β-type or α-β-type. 
   
   
       13 . The method of fabricating the striking plate as claimed in  claim 7 , wherein the second crystallization phase comprises α′-type or α″-type. 
   
   
       14 . The method of fabricating the striking plate as claimed in  claim 7 , wherein the plate body is made of Ti alloy.