High Volume Density Polycrystalline Diamond With Working Surfaces Depleted Of Catalyzing Material

Abstract

Disclosed is a method for manufacturing a polycrystalline diamond or diamond-like element with greatly improved wear resistance without loss of impact strength. These elements are formed with a binder-catalyzing material in a high-temperature, high-pressure (HTHP) process. The PCD element has a body with a plurality of bonded diamond or diamond-like crystals forming a continuous diamond matrix that has a diamond volume density greater than 85%. Interstices among the diamond crystals form a continuous interstitial matrix containing a catalyzing material. The diamond matrix table is formed and integrally bonded with a metallic substrate containing the catalyzing material during the HTHP process. The diamond matrix body has a working surface, where a portion of the interstitial matrix in the body adjacent to the working surface is substantially free of the catalyzing material, and the remaining interstitial matrix contains the catalyzing material. Typically, less than about 70% of the body of the diamond matrix table is free of the catalyzing material.

1 . A polycrystalline diamond element comprising a body of bonded diamonds with a working surface integrally formed with a metallic substrate, the body having at least an 85% by volume diamond density, wherein a first volume of the body remote from the working surface contains a catalyzing material and a second volume of the body adjacent to the working surface is substantially free of the catalyzing material to a depth from the working surface, wherein a thermal gradient of the bonded diamonds causes a 950 degrees C. temperature at the working surface to be less than 750 degrees C. at the depth; the element comprising a preform cutting element having a facing table and a cutting surface, wherein the working surface comprises a portion of the cutting surface.  
     
     
         2 . The polycrystalline diamond element of  claim 1 , wherein the thermal gradient is greater than 1000 degrees C. per mm.  
     
     
         3 . The polycrystalline diamond element of  claim 2 , wherein the thermal gradient is greater than 2000 degrees C. per mm.  
     
     
         4 . The polycrystalline diamond element of  claim 1 , wherein the first volume of the body contacts the substrate and has an average thickness greater than 0.15 mm.  
     
     
         5 . The polycrystalline diamond element of  claim 1 , wherein a majority of the catalyzing material remaining in the second volume of the body adheres to surfaces of diamond crystals.  
     
     
         6 . The polycrystalline diamond element of  claim 1 , wherein an amount of catalyzing material within the second volume of the body continuously decreases with distance from the first volume.  
     
     
         7 . The polycrystalline diamond element of  claim 1  wherein the first volume comprises more than 30% of the body remote from the working surface.  
     
     
         8 . The polycrystalline diamond element of  claim 7  wherein the substrate is tungsten carbide with an iron group binder material.  
     
     
         9 . The polycrystalline diamond element of  claim 1 , wherein the cutting element is mounted upon a cutting face of a fixed cutter rotary drill bit.  
     
     
         10 . The polycrystalline diamond element of  claim 1 , wherein the cutting element is mounted upon a body of a rolling cutter drill bit.  
     
     
         11 . The polycrystalline diamond element of  claim 4 , wherein the thermal gradient is greater than 1000 degrees C. per mm.  
     
     
         12 . The polycrystalline diamond element of  claim 12 , wherein the thermal gradient is greater than 2000 degrees C. per mm.  
     
     
         13 . The polycrystalline diamond element of  claim 4 , wherein a majority of the catalyzing material remaining in the second volume of the body adheres to surfaces of diamond crystals.  
     
     
         14 . The polycrystalline diamond element of  claim 4 , wherein an amount of catalyzing material within the second volume of the body continuously decreases with distance from the first volume.  
     
     
         15 . The polycrystalline diamond element of  claim 4  wherein the first volume comprises more than 30% of the body remote from the working surface.  
     
     
         16 . The polycrystalline diamond element of  claim 15  wherein the substrate is tungsten carbide with an iron group binder material.  
     
     
         17 . The polycrystalline diamond element of  claim 4 , wherein the cutting element is mounted upon a cutting face of a fixed cutter rotary drill bit.  
     
     
         18 . The polycrystalline diamond element of  claim 4 , wherein the cutting element is mounted upon a body of a rolling cutter drill bit.  
     
     
         19 . A polycrystalline diamond element comprising a diamond containing body formed with a substrate of tungsten carbide with an iron group binder material, the body having at least an 85% by volume diamond density and an interstitial matrix, wherein the interstitial matrix in the body adjacent to a working surface is substantially free of the catalyzing material to a depth from the working surface, and the interstitial matrix where the body contacts the substrate contains the catalyzing material and has an average thickness greater than 0.15 mm, wherein a thermal gradient of the bonded diamonds causes a 950 degrees C. temperature at the working surface to be less than 750 degrees C. at the depth; the diamond element comprising a preform cutting element having a facing table and a cutting surface, wherein the working surface comprises a portion of the cutting surface.  
     
     
         20 . The polycrystalline diamond element of  claim 19 , wherein the thermal gradient is greater than 1000 degrees C. per mm.  
     
     
         21 . The polycrystalline diamond element of  claim 19 , wherein the thermal gradient is greater than 2000 degrees C. per mm.  
     
     
         22 . The polycrystalline diamond element of  claim 19 , wherein the interstitial matrix in the body adjacent to the working surface of the body has a diamond density higher than elsewhere in the body.  
     
     
         23 . The polycrystalline diamond element of  claim 19 , wherein a majority of the catalyzing material remaining in the interstitial matrix in the body adjacent to the working surface of the body adheres to surfaces of diamond crystals.  
     
     
         24 . The polycrystalline diamond element of  claim 19 , wherein an amount of catalyzing material within the interstitial matrix in the body adjacent to the working surface of the body continuously decreases with distance from the remaining interstitial matrix.  
     
     
         25 . The polycrystalline diamond element of  claim 19 , wherein the cutting element is mounted upon a cutting face of a fixed cutter rotary drill bit.  
     
     
         26 . The polycrystalline diamond element of  claim 19 , wherein the cutting element is mounted upon a body of a rolling cutter drill bit.  
     
     
         27 . The polycrystalline diamond element of  claim 22 , wherein a majority of the catalyzing material remaining in the second volume of the body adheres to surfaces of diamond crystals.  
     
     
         28 . The polycrystalline diamond element of  claim 22 , wherein an amount of catalyzing material within the second volume of the body continuously decreases with distance from the first volume.  
     
     
         29 . The polycrystalline diamond element of  claim 22  wherein the first volume comprises more than 30% of the body remote from the working surface.  
     
     
         30 . The polycrystalline diamond element of  claim 22 , wherein the cutting element is mounted upon a cutting face of a fixed cutter rotary drill bit.  
     
     
         31 . The polycrystalline diamond element of  claim 22 , wherein the cutting element is mounted upon a body of a rolling cutter drill bit.