A polycrystalline super hard construction and a method for making same

Abstract

A polycrystalline super hard construction comprising a body of polycrystalline diamond (PCD) material and a plurality of interstitial regions between inter-bonded diamond grains forming the polycrystalline diamond material; the body of PCD material comprises a working surface positioned along an outside portion of the body; a first region substantially free of a solvent/catalysing material; a second region remote from the working surface that includes solvent/catalysing material in a plurality of the interstitial regions; and a substrate attached to the second region along an interface. The first region extends a depth from the working surface and the thickness of the second region between the interface with the substrate and an interface with the first region is between around 20 microns to around 200 microns at one or more points along the interface with the substrate.

1 . A polycrystalline super hard construction comprising a body of polycrystalline diamond (PCD) material and a plurality of interstitial regions between inter-bonded diamond grains forming the polycrystalline diamond material; the body of PCD material comprising:
 a working surface positioned along an outside portion of the body;   a first region substantially free of a solvent/catalysing material;   a second region remote from the working surface that includes solvent/catalysing material in a plurality of the interstitial regions; and   a substrate attached to the second region along an interface;   wherein the first region extends a depth from the working surface; and the thickness of the second region between the interface with the substrate and an interface with the first region is between around 20 microns to around 200 microns at one or more points along the interface with the substrate.   
     
     
         2 . The polycrystalline super hard construction of  claim 1 , wherein the thickness of the second region is between around 50 microns to around 200 microns; or between around 100 microns to around 200 microns; or between around 150 microns to around 200 microns. 
     
     
         3 . The polycrystalline super hard construction of  claim 1 , wherein the interface between the first region and the second region and/or the interface between the second region and the substrate is substantially planar; or the interface between the second region and the substrate is substantially non-planar and comprises one or more features protruding into or extending from one or other of the body of PCD material or substrate. 
     
     
         4 . The polycrystalline super hard construction of  claim 1 , wherein the first region is spaced from the interface with the substrate or one or more features extending therefrom at all points along the interface with the substrate. 
     
     
         5 .- 6 . (canceled) 
     
     
         7 . The polycrystalline super hard construction of  claim 1 , wherein the first and/or second regions comprise diamond grains of two or more diamond grain sizes. 
     
     
         8 . The polycrystalline super hard construction of  claim 7 , wherein the diamond grains have an associated mean free path; the solvent/catalyst at least partially filling a plurality of the interstitial regions in the second region having an associated mean free path;
 wherein:
 the median of the mean free path associated with the solvent/catalyst divided by (Q3−Q1) for the solvent/catalyst is greater than or equal to 0.5, where Q1 is the first quartile and Q3 is the third quartile; and 
 the median of the mean free path associated with the diamond grains divided by (Q3−Q1) for the diamond grains is less than 0.6. 
   
     
     
         9 . The polycrystalline super hard construction of  claim 8 , wherein the median of the mean free path associated with the solvent/catalyst divided by (Q3−Q1) for the solvent/catalyst is greater than or equal to 0.6. 
     
     
         10 . The polycrystalline super hard construction of  claim 8 , wherein the median of the mean free path associated with the solvent/catalyst divided by (Q3−Q1) for the solvent/catalyst is greater than or equal to 0.8. 
     
     
         11 . The polycrystalline super hard construction of  claim 8 , wherein the median of the mean free path associated with the solvent/catalyst divided by (Q3−Q1) for the solvent/catalyst is greater than or equal to 0.83. 
     
     
         12 . The polycrystalline super hard construction of  claim 8 , wherein the median of the mean free path associated with the diamond grains divided by (Q3−Q1) for the diamond grains is less than 0.5. 
     
     
         13 . The polycrystalline super hard construction of  claim 8 , wherein the median of the mean free path associated with the diamond grains divided by (Q3−Q1) for the diamond grains is less than 0.47. 
     
     
         14 . The polycrystalline super hard construction of  claim 8 , wherein the median of the mean free path associated with the diamond grains divided by (Q3−Q1) for the diamond grains is less than 0.4. 
     
     
         15 .- 17 . (canceled) 
     
     
         18 . A polycrystalline super hard construction according to  claim 1 , wherein the catalyst/solvent at least partially filling a plurality of the interstitial regions forms non-diamond phase pools, the non-diamond phase pools each having an individual cross-sectional area,
 wherein the percentage of catalyst/solvent in the total area of a cross-section of the body of polycrystalline diamond material is between around 0 to 12%, and the mean of the individual cross-sectional areas of the non-diamond phase pools in an analysed image of a cross-section through the body of polycrystalline material is less than around 0.7 microns squared when analysed using an image analysis technique at a magnification of around 1000 and an image area of 1280 by 960 pixels.   
     
     
         19 . A polycrystalline super hard construction according to  claim 18 , wherein the percentage of catalyst/solvent in the total area of a cross-section of the body of polycrystalline diamond material is between around 0 to 10%, and the mean of the individual cross-sectional areas of the non-diamond phase pools in an analysed image of a cross-section through the body of polycrystalline material is less than around 0.7 microns squared when analysed using an image analysis technique at a magnification of around 1000 and an image area of 1280 by 960 pixels. 
     
     
         20 . A polycrystalline super hard construction according to  claim 18 , wherein the percentage of catalyst/solvent in the total area of a cross-section of the body of polycrystalline diamond material is between around 0 to 8%, and the mean of the individual cross-sectional areas of the non-diamond phase pools in an analysed image of a cross-section through the body of polycrystalline material is less than around 0.7 microns squared when analysed using an image analysis technique at a magnification of around 1000 and an image area of 1280 by 960 pixels. 
     
     
         21 . A polycrystalline super hard construction according to  claim 18 , wherein the mean of the individual cross-sectional areas of the non-diamond phase pools in an analysed image of a cross-section through the body of polycrystalline material is less than around 0.5 microns squared when analysed using an image analysis technique at a magnification of around 1000 and an image area of 1280 by 960 pixels. 
     
     
         39 . A polycrystalline super hard construction according to  claim 18 , wherein the mean of the individual cross-sectional areas of the non-diamond phase pools in an analysed image of a cross-section through the body of polycrystalline material is less than around 0.4 microns squared when analysed using an image analysis technique at a magnification of around 1000 and an image area of 1280 by 960 pixels. 
     
     
         22 . A polycrystalline super hard construction according to  claim 18 , wherein the mean of the individual cross-sectional areas of the non-diamond phase pools in an analysed image of a cross-section through the body of polycrystalline material is less than around 0.34 microns squared when analysed using an image analysis technique at a magnification of around 1000 and an image area of 1280 by 960 pixels. 
     
     
         23 .- 28 . (canceled) 
     
     
         29 . A method for making a thermally stable polycrystalline diamond construction comprising the steps of:
 treating a polycrystalline diamond construction comprising a polycrystalline diamond body, the polycrystalline diamond body comprising a plurality of interbonded diamond grains and interstitial regions disposed therebetween, to remove a solvent/catalyst material from a first region of the diamond body while allowing the solvent/catalyst material to remain in a second region of the diamond body;   further comprising during the step of treating, controlling the depth of the first region so that it extends from a working surface of the diamond body to a depth wherein the thickness of the second region between the interface with the substrate and an interface with the first region is between around 20 microns to around 200 microns at one or more points along the interface with the substrate.   
     
     
         30 .- 38 . (canceled)