Control of defects and sweep pattern in pdc by treating carbide substrate before sweep

Abstract

A method for forming a polycrystalline diamond compact (PDC) includes treating a carbide substrate having a cobalt content therein with an acid, e.g., aqua regia, to remove cobalt from a surface portion of the carbide substrate; disposing diamond crystals on the treated carbide substrate; disposing a sweep material on the diamond crystals on a surface of the diamond opposite the carbide substrate; and applying high temperature and pressure to the carbide substrate, the diamond crystals and the sweep material such that the diamond crystals are sintered into a polycrystalline diamond attached to the carbide substrate to form the polycrystalline diamond compact.

What is claimed is: 
     
         1 . A method for forming a polycrystalline diamond compact (PDC), comprising:
 treating a cemented carbide substrate having a binder content therein with an acid/leaching agent to remove the binder content from a surface portion of the cemented carbide substrate;   disposing a plurality of diamond crystals on the treated cemented carbide substrate;   disposing a sweep material on the plurality of diamond crystals on a surface of the diamond at a distance from the cemented carbide substrate; and   applying high temperature and pressure to the carbide substrate, the diamond crystals and the sweep material such that the diamond crystals are sintered into a polycrystalline diamond attached to the carbide substrate to form the polycrystalline diamond compact.   
     
     
         2 . The method of  claim 1 , wherein the sweep material is cobalt. 
     
     
         3 . The method of  claim 1 , wherein an interface between diamond crystals and the cemented carbide substrate is planar. 
     
     
         4 . The method of  claim 1 , wherein an interface between diamond crystals and the cemented carbide substrate is non-planar. 
     
     
         5 . The method of  claim 4 , wherein the interface is a deep valley from the diamond into the cemented carbide substrate. 
     
     
         6 . The method of  claim 4 , wherein the interface is a raised central portion on the cemented carbide substrate. 
     
     
         7 . The method of  claim 1 , wherein the sweep material is cobalt disc. 
     
     
         8 . The method of  claim 7 , wherein the sweep material further includes additive materials. 
     
     
         9 . The method of  claim 8 , wherein the additive materials are from at least one of chromium, nickel and iron. 
     
     
         10 . The method of  claim 1 , wherein high pressure and high temperature are at least 60 Kbar and 1400° C., respectively. 
     
     
         11 . A method for forming a polycrystalline diamond compact (PDC), comprising:
 treating a cemented carbide substrate having a binder content therein with an acid/leaching agent to remove the binder content from a surface portion of the carbide substrate;   mixing a plurality of diamond crystals with a sweep material;   disposing the mixture of the plurality of diamond crystals with the sweep material on the treated cemented carbide substrate; and   applying high temperature and pressure to the carbide substrate, the diamond crystals and the sweep material such that the diamond crystals are sintered into a polycrystalline diamond attached to the carbide substrate to form the polycrystalline diamond compact.   
     
     
         12 . The method of  claim 11 , further comprising adding additive materials to the mixture of the plurality of diamond crystals with the sweep material. 
     
     
         13 . The method of  claim 12 , wherein the additive materials are from at least one of chromium, nickel and iron. 
     
     
         14 . The method of  claim 11 , wherein high pressure and high temperature are at least 60 Kbar and 1400° C., respectively. 
     
     
         15 . The method of  claim 11 , wherein an interface between diamond and the cemented carbide substrate is planar. 
     
     
         16 . The method of  claim 11 , wherein an interface between diamond and the cemented carbide substrate is non-planar. 
     
     
         17 . The method of  claim 16 , wherein the interface is a deep valley from the diamond into the cemented carbide substrate. 
     
     
         18 . The method of  claim 16 , wherein the interface is a raised central portion on the cemented carbide substrate. 
     
     
         19 . A polycrystalline diamond compact, comprising:
 a substrate; and   a polycrystalline diamond table bonded to the substrate, wherein the polycrystalline diamond table is substantially free of a sweep material from the substrate wherein the polycrystalline diamond table is not leached.   
     
     
         20 . The polycrystalline diamond compact of  claim 19 , wherein the sweep material is cobalt. 
     
     
         21 . The polycrystalline diamond compact of  claim 19 , wherein the sweep material is mixed with a plurality of diamonds before the plurality of diamonds are sintered onto the polycrystalline diamond table. 
     
     
         22 . The polycrystalline diamond compact of  claim 19 , wherein the sweep material is from a cobalt disc on the plurality of diamond crystals on a surface of the diamond crystals at a distance from the cemented carbide substrate. 
     
     
         23 . The polycrystalline diamond compact of  claim 19 , wherein an interface between diamond and the cemented carbide substrate is planar. 
     
     
         24 . The polycrystalline diamond compact of  claim 19 , wherein an interface between diamond and the cemented carbide substrate is non-planar. 
     
     
         25 . The polycrystalline diamond compact of  claim 19 , wherein the interface is a deep valley from the diamond into the cemented carbide substrate. 
     
     
         26 . The polycrystalline diamond compact of  claim 19 , wherein the interface is a raised central portion on the cemented carbide substrate.