Polycrystalline diamond element

Abstract

An embodiment of a PCD insert comprises an embodiment of a PCD element joined to a cemented carbide substrate at an interface. The PCD element has internal diamond surfaces defining interstices between them. The PCD element further comprises a working surface and a low melting point region adjacent the working surface in which the interstices are at least partially filled with a low melting point metallic material having a melting point of less than about 1,300 degrees centigrade at atmospheric pressure, or less than about 1,200 degrees centigrade at atmospheric pressure. The PCD element includes an intermediate region, the interstices of the intermediate region being at least partially filled with a catalyst material for diamond.

1 . A polycrystalline diamond (PCD) element having internal diamond surfaces, the internal diamond surfaces defining interstices between them, the PCD element comprising a working surface, a low melting point region adjacent the working surface and in which the interstices are at least partially filled with a low melting point metallic material having a melting point of less than about 1,300 degrees centigrade at atmospheric pressure, and an intermediate region extending a distance of between about 5 microns and about 600 microns from a boundary defined by the low melting point region, the interstices of the intermediate region being at least partially filled with a catalyst material for diamond. 
     
     
         2 . A polycrystalline diamond element according to  claim 1 , in which the intermediate region extends a distance from the boundary of at most about 400 microns. 
     
     
         3 . A polycrystalline diamond element according to  claim 1 , in which the intermediate region extends a distance from the boundary of at least about 5 microns. 
     
     
         4 . A polycrystalline diamond element according to  claim 1 , in which the interstices of the intermediate region are at least 50% filled with a sintering aid or catalyst material for diamond. 
     
     
         5 . A polycrystalline diamond element according to  claim 1 , in which the low melting point region extends a depth into the PCD element from the working surface, the depth being at most about 1,000 microns. 
     
     
         6 . A polycrystalline diamond element according to  claim 1 , in which the low melting point region extends a depth into the PCD element from the working surface, the depth being at least about 5 microns. 
     
     
         7 . A polycrystalline diamond element according to  claim 1 , in which the low melting point region is in the form of a stratum or layer. 
     
     
         8 . A polycrystalline diamond element according to  claim 1 , in which the interstices within the low melting point region are at least 50% filled with the low melting point metallic material. 
     
     
         9 . A polycrystalline diamond element according to  claim 1 , in which the low melting point metallic material has a melting point lower than 1,100 degrees centigrade at atmospheric pressure. 
     
     
         10 . A polycrystalline diamond element according to  claim 1 , in which the low melting point metallic material has a melting point greater than 600 degrees centigrade at atmospheric pressure. 
     
     
         11 . A polycrystalline diamond element according to  claim 1 , in which the low melting point metallic material is not capable of reacting to form a stable carbide at less than 1,000 degrees centigrade at atmospheric pressure. 
     
     
         12 . A polycrystalline diamond element according to  claim 1 , in which the low melting point metallic material is Ag, Mg, Cu or Pb in elemental form or an alloy including any of these elements. 
     
     
         13 . A polycrystalline diamond element according to  claim 1 , in which the low melting point metallic material is Ag or Cu in elemental form or an alloy including either of these elements. 
     
     
         14 . An insert for a tool, the insert comprising a polycrystalline diamond element according to  claim 1 . 
     
     
         15 . A tool comprising an insert according to  claim 14 . 
     
     
         16 . A method for making a polycrystalline diamond (PCD) element, the method including providing a PCD body comprising a sintering aid within interstices of the PCD body, removing at least some of the sintering aid from a portion of the polycrystalline diamond element to form a porous region adjacent a working surface, and infiltrating or permeating at least a portion of the porous region with low melting point metallic material having a low melting point of less than 1,300 degrees centigrade at atmospheric pressure. 
     
     
         17 . A method according to  claim 16 , in which substantially all of the sintering aid is removed from the polycrystalline diamond element.