Cutting elements having accelerated leaching rates and methods of making the same

Abstract

Cutting elements having accelerated leaching rates and methods of making the same are disclosed herein. In one embodiment, a method of forming a cutting element includes assembling a reaction cell having diamond particles, a non-catalyst material, a catalyst material, and a substrate within a refractory metal container, where the non-catalyst material is generally immiscible in the catalyst material at a sintering temperature and pressure. The method also includes subjecting the reaction cell and its contents to a high pressure high temperature sintering process to form a polycrystalline diamond body that is attached to the substrate. The method further includes contacting at least a portion of the polycrystalline diamond body with a leaching agent to remove catalyst material and non-catalyst material from the diamond body, where a leaching rate of the catalyst material and the non-catalyst material exceeds a conventional leaching rate profile by at least about 30%.

1 . A method of forming a cutting element, comprising:
 assembling a reaction cell comprising a plurality of diamond particles, a non-catalyst material, a catalyst material, and a substrate within a refractory metal container, wherein the non-catalyst material is generally immiscible in the catalyst material when both are held at the greater of the melting or liquidus temperature of the catalyst material or the non-catalyst material;   subjecting the reaction cell and its contents to a high pressure high temperature sintering process in which the catalyst material promotes formation of inter-diamond bonding between adjacent diamond particles to form a poly crystalline diamond body that is attached to the substrate;   contacting at least a portion of the polycrystalline diamond body with a leaching agent to remove catalyst material and non-catalyst material from the diamond body,   a conventional leaching profile comprising time measured along a first axis and a corresponding weight loss percentage presented along a second axis; and   wherein a leaching rate at which the catalyst material and the non-catalyst material are leached from the diamond body exceeds a conventional leaching rate profile by at least about 30%.   
     
     
         2 . The method of  claim 1 , wherein the leaching rate of the catalyst material and the non-catalyst material exceeds the convention leaching rate profile by at least about 40%. 
     
     
         3 . The method of  claim 1 , wherein the leaching rate of the catalyst material and the non-catalyst material exceeds the convention leaching rate profile by up to about 60%. 
     
     
         4 . The method of  claim 1 , wherein a leached depth of 800 μιη from the working surface of the polycrystalline diamond body is achieved in less than about 7 days of exposure to the leaching agent. 
     
     
         5 . The method of  claim 4 , wherein a leached depth of 800 μιη from the working surface of a polycrystalline diamond body according to the conventional leaching rate profile is achieved in about 10 days of exposure to the leaching agent. 
     
     
         6 . The method according to  claim 1 , wherein the non-catalyst material has a lower liquidus or melting temperature than the liquidus or melting temperature of the catalyst material. 
     
     
         7 . The method according to  claim 1 , wherein the non-catalyst material has a higher rate of reaction with the leaching agent than the catalyst material. 
     
     
         8 . The method of  claim 1 , wherein high pressure high temperature sintering process includes:
 melting the non-catalyst material and pushing the melted non-catalyst material through at least a portion of the plurality of diamond particles, thereby surrounding at least a portion of the plurality of individual diamond particles; and   melting the catalyst material and pushing the melted catalyst material through at least a portion of the plurality of diamond particles and displacing a portion of the non-catalyst material from interstitial regions between the individual diamond grains.   
     
     
         9 . The method of  claim 1 , wherein the non-catalyst material is mixed with the diamond particles prior to being assembled in the reaction cell. 
     
     
         10 . The method of  claim 1 , wherein the catalyst material is incorporated into the substrate. 
     
     
         11 . The method of  claim 1 , wherein the catalyst material is positioned in a catalyst source that is separate from the substrate. 
     
     
         12 . The method of  claim 1 , further comprising the selecting of a multimodal feed that comprises a first population of diamond particles having a first particle size distribution function and a second population of diamond particles having a second particle size distribution function. 
     
     
         13 . The method of  claim 12 , wherein the multimodal feed further comprises a third population of diamond particles having a third particle size distribution function. 
     
     
         14 . The method of  claim 1 , wherein the diamond body comprises a first portion positioned proximate to the substrate and having a first particle size distribution function and a second portion positioned distally from the substrate and having a second particle size distribution function. 
     
     
         15 . The method of  claim 14 , wherein the first portion has a median particle size that is smaller than a median particle size of the second portion. 
     
     
         16 . The method of  claim 14 , wherein the first portion has a median particle size that is larger than a median particle size of the second portion. 
     
     
         17 . The method of  claim 1 , wherein the diamond body further comprises metal carbide, and a metal carbide concentration within the diamond body is less than about 70% of a conventional metal carbide concentration. 
     
     
         18 . The method of  claim 1 , wherein the non-catalyst material is lead or alloys thereof. 
     
     
         19 . The method of  claim 1 , wherein the non-catalyst material is bismuth or alloys thereof. 
     
     
         20 . The method of  claim 1 , wherein the non-catalyst material is positioned between the diamond particles and the substrate. 
     
     
         21 . A cutting element, comprising:
 a substrate comprising a metal carbide and a catalyst material; and   a poly crystalline diamond body bonded to the substrate, the poly crystalline diamond body comprising a plurality of diamond grains bonded to adjacent diamond grains in diamond-to-diamond bonds and a plurality of interstitial regions positioned between adjacent diamond grains, the plurality of interstitial regions comprising an immiscible non-catalyst material, the catalyst material, the metal carbide, or combinations thereof,   wherein a metal carbide concentration within the diamond body is less than about 70% of a conventional metal carbide concentration.   
     
     
         22 . The cutting element of  claim 21 , wherein the metal carbide comprises cemented tungsten carbide. 
     
     
         23 . The cutting element of  claim 21 , wherein the non-catalyst material has a lower liquidus or melting temperature than the liquidus or melting temperature of the catalyst material. 
     
     
         24 . The cutting element of  claim 21 , wherein the diamond particles comprise a multimodal population of bonded diamond grains that comprises a first population of diamond particles having a first particle size distribution function and a second population of diamond particles having a second particle size distribution function. 
     
     
         25 . The cutting element of  claim 24 , wherein the multimodal population of bonded diamond grains further comprises a third population of diamond particles having a third particle size distribution function. 
     
     
         26 . The cutting element of  claim 21 , wherein the poly crystalline diamond body comprises a first portion positioned proximate to the substrate and having a first particle size distribution function and a second portion positioned distally from the substrate and having a second particle size distribution function. 
     
     
         27 . The cutting element of  claim 26 , wherein the first portion has a median particle size that is smaller than a median particle size of the second portion. 
     
     
         28 . The cutting element of  claim 26 , wherein the first portion has a median particle size that is larger than a median particle size of the second portion. 
     
     
         29 . A drill bit, comprising:
 a bit body comprising a leading end structure for drilling a subterranean formation; and a plurality of cutting elements mounted to the blades, at least one of the plurality of cutting elements comprising:   a substrate comprising a metal carbide and a catalyst material; and a polycrystalline diamond body bonded to the substrate, the polycrystalline diamond body comprising a plurality of diamond grains bonded to adjacent diamond grains in diamond-to-diamond bonds, the polycrystalline diamond body further comprising a plurality of interstitial regions positioned between adjacent diamond grains, the plurality of interstitial regions comprising an immiscible non-catalyst material, catalyst material, metal carbide, or combinations thereof,   wherein a metal carbide concentration within the diamond body is less than about 70% of a conventional metal carbide concentration.   
     
     
         30 . A method of forming a cutting element, comprising:
 assembling a reaction cell comprising a plurality of diamond particles, a non-catalyst material, a catalyst material, and a substrate within a refractory metal container, wherein the non-catalyst material is generally immiscible in the catalyst material when both are held at the greater of the melting or liquidus temperature of the catalyst material or the non-catalyst material;   subjecting the reaction cell and its contents to a high pressure high temperature sintering process in which the catalyst material promotes formation of inter-diamond bonding between adjacent diamond particles to form a poly crystalline diamond body that is attached to the substrate;   contacting at least a portion of the polycrystalline diamond body with a leaching agent to remove catalyst material and non-catalyst material from the diamond body,   wherein the non-catalyst material has a higher rate of reaction with the leaching agent than the catalyst material.   
     
     
         31 . The method of  claim 30 , wherein the non-catalyst material has a lower liquidus or melting temperature than the liquidus or melting temperature of the catalyst material. 
     
     
         32 . The method of  claim 30 , wherein a leached depth of 800 μιη from the working surface of the diamond body is achieved in less than about 7 days of exposure to the leaching agent. 
     
     
         33 . The method of  claim 30 , wherein the diamond body has a non-zero non-catalyst material concentration that increases from the substrate to the working surface,
 wherein when leaching agent is contacted to the working surface, a reaction rate of the leaching reaction decreases with increasing distance from the working surface.