Fracture resistant domed insert

Abstract

A cutting element for earth-boring drill bits comprising a generally domed cutting surface comprising a superabrasive material, formed by a high-pressure high-temperature sintering method known in the art, integrally bonded to a cylindrical substrate having a truncated conical interfacial surface, consisting of a top surface and a circumferential shoulder joined by tapered sidewalls, and the base of the substrate being adapted for insertion into an earth-boring tool. The top surface of the substrate may form a circle, a square, or a polygon, and the sidewalls may be smooth or form one or more polygons.

What is claimed:  
     
         1 . A cutting element for earth-boring drill bits, comprising: 
 a generally domed cutting surface comprising a superabrasive material, formed by a high-pressure high-temperature sintering method known in the art, integrally bonded to a cylindrical substrate having a generally truncated conical interfacial surface, consisting of a top surface and a circumferential shoulder joined by tapered side walls, and the base of the substrate being adapted for insertion into an earth-boring tool.    
     
     
         2 . The cutting element of  claim 1 , wherein the surfaces of the generally domed cutting table comprise polygonal shaped surfaces.  
     
     
         3 . The cutting element of  claim 1 , wherein the generally domed cutting table has sufficient thickness to withstand compressive drilling of subterranean formations.  
     
     
         4 . The cutting element of  claim 1 , wherein the substrate is composed of a fracture tough material selected from the group consisting of cemented metal carbide.  
     
     
         5 . The cutting element of  claim 1 , wherein the truncated interfacial surface comprises a top surface forming a circle, a square, a polygon, or a combination thereof.  
     
     
         6 . The cutting element of  claim 1 , wherein the tapered walls of the interfacial are surface smooth.  
     
     
         7 . The cutting element of  claim 1 , wherein the tapered walls of the interfacial surface form one or more polygons.  
     
     
         8 . The cutting element of  claim 1 , wherein the tapered walls of the interfacial surface form a truncated pyramid.  
     
     
         9 . The cutting element of  claim 1 , wherein the tapered sidewalls join the circumferential shoulder at an oblique angle.  
     
     
         10 . The cutting element of  claim 1 , wherein the tapered sidewalls join the shoulder and top along a filleted surface.