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; and a second region remote from the working surface that includes solvent/catalysing material in a plurality of the interstitial regions. The first region extends to a depth of at least about 400 microns from the working surface into the body of polycrystalline diamond material.

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; and   a second region remote from the working surface that includes solvent/catalysing material in a plurality of the interstitial regions;   wherein the first region extends to a depth of at least about 400 microns from the working surface into the body of polycrystalline diamond material.   
     
     
         2 . The polycrystalline super hard construction of  claim 1 , wherein a majority of the diamond grains in the body within at least a depth of 400 microns from the working surface have a surface which is substantially free of catalyzing material, the remaining grains contacting catalyzing material. 
     
     
         3 .- 6 . (canceled) 
     
     
         7 . The polycrystalline super hard construction of  claim 1 , wherein the first region extends from the working surface to a depth of:
 at least about 400 microns to about 800 microns; or   at least about 450 microns to about 1200 microns; or   at least about 450 microns to about 1400 microns.   
     
     
         8 .- 9 . (canceled) 
     
     
         10 . 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. 
     
     
         11 . The polycrystalline super hard construction of  claim 10 , 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.   
     
     
         12 . The polycrystalline super hard construction of  claim 11 , 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. 
     
     
         13 . The polycrystalline super hard construction of  claim 11 , 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. 
     
     
         14 . The polycrystalline super hard construction of  claim 11 , 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. 
     
     
         15 . The polycrystalline super hard construction of  claim 1 , 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. 
     
     
         16 . The polycrystalline super hard construction of  claim 11 , 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. 
     
     
         17 . The polycrystalline super hard construction of  claim 11 , 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. 
     
     
         18 .- 20 . (canceled) 
     
     
         21 . 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.   
     
     
         22 . A polycrystalline super hard construction according to  claim 21 , 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. 
     
     
         23 . A polycrystalline super hard construction according to  claim 21 , 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. 
     
     
         24 . A polycrystalline super hard construction according to  claim 21 , 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. 
     
     
         25 . A polycrystalline super hard construction according to  claim 21 , 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. 
     
     
         26 . A polycrystalline super hard construction according to  claim 21 , 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. 
     
     
         27 .- 32 . (canceled) 
     
     
         33 . 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 of not less than about 400 microns.   
     
     
         34 .- 37 . (canceled) 
     
     
         38 . The method of  claim 33 , wherein the step of treating comprises controlling the depth of the first region to be substantially constant across at least a part of the working surface; or to vary across at least a part of the working surface. 
     
     
         39 . The method of  claim 33 , wherein the step of treating comprises controlling the treatment such that the first region extends across substantially the whole of the working surface; or the step of treating comprises masking a portion of the working surface such that during treating the first region extends across only a part of the working surface. 
     
     
         40 .- 41 . (canceled)