High diamond frame strength pcd materials

Abstract

The present disclosure relates to cutting elements incorporating polycrystalline diamond bodies used for subterranean drilling applications, and more particularly, to polycrystalline diamond bodies having high diamond frame strength and methods for forming and evaluating such polycrystalline diamond bodies. A polycrystalline diamond body is provided, having a top surface, a cutting edge meeting the top surface, and a first region including at least a portion of the cutting edge. The first portion exhibits a diamond frame strength of about 1200 MPa or greater, or about 1300 MPa or greater.

What is claimed is: 
     
         1 . A method of forming a wear-resistant polycrystalline diamond cutting element, comprising:
 providing a powder mixture comprising a plurality of diamond particles having an average particle size of 20 microns or less;   compacting the powder mixture to compress the diamond particles; and   subjecting the powder mixture and a catalyst material to a high temperature and high pressure sintering process sufficient to form a polycrystalline diamond body, at least a region of the polycrystalline diamond body comprising a microstructure having a plurality of bonded-together diamond crystals having a diamond frame strength of at least 1200 MPa,   wherein the sintering process comprises applying a pressure within the range of approximately 7.0 to 8.2 GPa.   
     
     
         2 . The method of  claim 1 , wherein the high temperature and high pressure sintering process comprises applying a pressure of approximately 7.0 GPa. 
     
     
         3 . The method of  claim 2 , wherein the powder mixture comprises a first mixture of diamond particles having an average particle size in the range of 15-20 microns, and a second mixture of diamond particles having an average particle size in the range of 2-4 microns, wherein the first mixture comprises approximately 80% of the powder mixture, and the second mixture comprises approximately 20% of the powder mixture. 
     
     
         4 . The method of  claim 3 , wherein the region of the polycrystalline diamond body comprises a diamond volume fraction of at least 93%. 
     
     
         5 . The method of  claim 1 , wherein the pressure is within the range of approximately 7.0-7.5 GPa. 
     
     
         6 . The method of  claim 1 , wherein the bonded-together diamond crystals comprise a sintered grain size of approximately 5-7 microns. 
     
     
         7 . The method of  claim 1 , further comprising:
 dividing the diamond body into first and second portions;   removing the catalyst material from the first portion of the diamond body; and   determining a compressive stress in the first and second portions, wherein the first portion comprises a drop in compressive stress of about 15-25% compared to the second portion.   
     
     
         8 . A method of selecting a polycrystalline diamond body for wear-resistant applications, comprising:
 obtaining a polycrystalline diamond body comprising a material microstructure comprising a plurality of bonded-together diamond crystals and interstitial regions between the diamond crystals, the interstitial regions comprising a catalyst material;   substantially removing the catalyst material from at least a first region of the diamond body;   ascertaining a flexural strength of the first region; and   selecting the diamond body for a wear-resistant application based on the flexural strength of the first region of the diamond body, wherein the flexural strength of the first region of the selected diamond body is at least 1300 MPa, and wherein the increased flexural strength results in an increased wear resistance at elevated temperatures.   
     
     
         9 . The method of  claim 8 , further comprising dividing the polycrystalline diamond body into first and second portions and removing the catalyst material from the first portion to form the first region. 
     
     
         10 . The method of  claim 9 , further comprising determining a compressive stress in the first and second portions, wherein the first portion comprises a drop in compressive stress of about 15-25% compared to the second portion. 
     
     
         11 . A method for increasing a wear resistance of a polycrystalline diamond body, comprising:
 obtaining a mixture of diamond particles;   sintering the mixture at high temperature and high pressure in the presence of a catalyst material to form a polycrystalline diamond body; and   increasing a diamond frame strength of the polycrystalline diamond body to at least 1300 MPa, wherein increasing the diamond frame strength comprises at least one of increasing the pressure for sintering the polycrystalline diamond body to at least 7.0 GPa, or reducing an average particle size of the diamond particles in the mixture to below 16 microns,   wherein the increased diamond frame strength results in an increased wear resistance at elevated temperatures.