CUTTING ELEMENTS HAVING ACCELERATED LEACHING RATES AND METHODS OF MAKING THE SAME
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.