Thermally stable polycrystalline diamond material with gradient structure

Abstract

A diamond construction may include a diamond body comprising a plurality of bonded-together diamond crystals forming a matrix phase, and a plurality of interstitial regions disposed between the bonded-together diamond crystals, the diamond body comprising: a first diamond region extending a depth from a surface of the diamond body being substantially free of a catalyst material used to form the diamond body, wherein the first diamond region comprises the matrix phase and in at least a portion of the plurality of interstitial spaces, the first diamond region comprises a metal carbide and an inert metal, wherein the metal carbide is formed as a result of reaction between the diamond crystals in the matrix phase and a carbide-forming metal; and a second diamond region adjacent the first diamond region comprising the matrix phase and a Group VIII metal in the interstitial regions.

1 .- 20 . (canceled) 
     
     
         21 . A method for making a diamond construction, comprising:
 treating a diamond body having a material microstructure comprising a matrix phase of bonded-together diamond grains and interstitial regions disposed between the diamond grains, wherein a catalyst material used to form the diamond body during a first high pressure/high temperature condition is disposed within the interstitial regions, wherein during the step of treating, the catalyst material is removed from interstitial regions of the diamond body;   placing an infiltrant material next to the diamond body depleted of the catalyst material, wherein the infiltrant material comprises an alloy having at least two metals, one of the two metals being a carbide-forming metal, and the other of the two metals being an inert metal; and   subjecting the diamond body to second high pressure/high temperature condition in order to allow an alloy to infiltrate into interstitial regions and to form a metal carbide between the carbide-forming metal in the infiltrant material and the diamond grains within the interstitial regions at least adjacent to a surface of the diamond body.   
     
     
         22 . The method of  claim 21 , wherein the interstitial regions remote from the surface have a greater relative amount of inert metal and a lower relative amount of carbide therein as compared to the interstitial region adjacent the surface. 
     
     
         23 . The method of  claim 21 , wherein the second high pressure/high temperature condition comprises a temperature ranging from about 800 to 1700° C. 
     
     
         24 . The method of  claim 21 , wherein upon reaching melting of the infiltrant material, the temperature of the second high pressure/high temperature condition is changed at a rate of about 1 to 100° C./sec. 
     
     
         25 . The method of  claim 24 , wherein upon reaching melting of the infiltrant material, the temperature of the second high pressure/high temperature condition is changed at a rate of about 5 to 25° C./sec. 
     
     
         26 . The method of  claim 21 , further comprising:
 introducing another infiltrant into the interstitial regions depleted of the catalyst material and not occupied by the metal carbide or inert metal, wherein the another infiltrant is a Group VIII metal, and wherein the diamond body is substantially free of the catalyst material prior to this process.   
     
     
         27 . The method of  claim 21 , wherein after the step of treating, the catalyst material is allowed to remain in at least a part of a population of the interstitial regions. 
     
     
         28 . The method of  claim 21 , wherein the diamond construction comprises a metallic substrate attached to the diamond body. 
     
     
         29 . The method of  claim 21 , wherein during the step of introducing the infiltrant material, the second high pressure/high temperature condition is at a temperature that is less than that of the first high pressure/high temperature condition. 
     
     
         30 . The method of  claim 21 , wherein after the step of introducing the infiltrant material, the second high pressure/high temperature condition is at a temperature approximately the same as that of the first high pressure/high temperature condition. 
     
     
         31 . The method of  claim 21 , wherein after the step of introducing the infiltrant material, the second high pressure/high temperature condition is at a temperature that is higher than that of the first high pressure/high temperature condition. 
     
     
         32 . A method for making a diamond construction, comprising:
 placing a first infiltrant material next to the diamond body having a material microstructure of a matrix phase of bonded-together diamond grains and interstitial regions disposed between the diamond grains, the interstitial regions being substantially free a catalyst material used to form the diamond body, wherein the infiltrant material comprises an alloy having at least two metals, one of the two metals being a carbide-forming metal, and the other of the two metals being an inert metal;   introducing the first infiltrant material into interstitial regions within a first region of the diamond body to form a metal carbide between the carbide-forming metal in the infiltrant material and the diamond grains within the interstitial regions within the first region; and   introducing a second infiltrant material into the interstitial regions of a second region of the diamond body not occupied by the metal carbide or inert metal, the second infiltrant material infiltrating from a substrate material, thereby bonding the diamond body to the substrate material.   
     
     
         33 . The method of  claim 32 , wherein upon reaching melting of the infiltrant material, introducing the first infiltrant material comprises subjecting the diamond body and the first infiltrant material to high pressure high temperature conditions having the temperature increase at a rate between about 1 and 100° C./sec. 
     
     
         34 . The method of  claim 33 , wherein upon reaching melting of the infiltrant material, introducing the first infiltrant material comprises subjecting the diamond body and the first infiltrant material to high pressure high temperature conditions having the temperature increase at a rate between about 2 and 50° C./sec. 
     
     
         35 . The method of  claim 34 , wherein upon reaching melting of the infiltrant material, introducing the first infiltrant material comprises subjecting the diamond body and the first infiltrant material to high pressure high temperature conditions having the temperature increase at a rate between about 5 and 25° C./sec. 
     
     
         36 . The method of  claim 32 , wherein introducing the first infiltrant material comprises controlled high pressure high temperature conditions to form a gradient of the metal carbide and the inert metal within the first region of the diamond body. 
     
     
         37 . The method of  claim 32 , wherein introducing the second infiltrant material comprises subjecting the diamond body to high pressure high temperature conditions that are greater than that used to introduce the first infiltrant material. 
     
     
         38 . The method of  claim 32 , wherein the interstitial regions in the first region adjacent the second region of the diamond have a greater relative amount of inert metal and a lower relative amount of carbide therein as compared to the interstitial region remote from the second region of the diamond body. 
     
     
         39 . The method of  claim 21 , wherein the insert metal comprises at least one selected from the group consisting of Cu, Ag, Au, Pd, Pt, and combinations thereof. 
     
     
         40 . The method of  claim 21 , wherein the carbide-forming metal comprises at least one selected from the group consisting of Ti, Zr, Nb, Mo, W, Ta, V, Si, Cr, B, Hf, and combinations thereof.