Techniques for affecting leaching profiles in cutting elements for earth-boring tools and related cutting elements, earth-boring tools, and methods

Abstract

Cutting elements for earth-boring tools may include a cutting table secured to a substrate. The cutting table may include a first region at least substantially free of an infiltrant, a second region comprising the infiltrant, and a passageway extending from an exterior partially through the first region. A distance between the exterior and a boundary between the first region and the second region, as measured from a major surface of the cutting table, may not be constant. Methods of making cutting elements for earth-boring tools may involve placing a sacrificial material among grains of a superabrasive material. The grains of the superabrasive material and the sacrificial material may be exposed to elevated temperature and pressure in a presence of a catalyst material to form a cutting table. The sacrificial material and a portion of the catalyst material may be removed from a first region of the cutting table.

1 . A cutting element for an earth-boring tool, comprising:
 a cutting table secured to a substrate, the cutting table comprising:
 a first region at least substantially free of solid infiltrant material in interstitial spaces among interbonded grains of superabrasive material located proximate a cutting face of the cutting table; 
 a second region comprising solid infiltrant material in the interstitial spaces among the interbonded grains of the superabrasive material located proximate the substrate; and 
 a passageway extending from an exterior of the cutting table partially through the first region; and 
 wherein a distance between the exterior of the cutting table and a boundary between the first region and the second region, as measured from a major surface of the cutting table, is not constant. 
   
     
     
         2 . The cutting element for an earth-boring tool of  claim 1 , wherein the passageway extends from the exterior, partially through the first region, to a location spaced from the substrate by about 5% or more of a thickness of the cutting table, as measured along a longitudinal axis of the cutting element. 
     
     
         3 . The cutting element for an earth-boring tool of  claim 2 , wherein the passageway extends from the exterior, partially through the first region, to a location within the first region spaced from the boundary. 
     
     
         4 . The cutting element of  claim 1 , wherein a shortest distance between walls defining the passageway is greater than a greatest distance between interbonded grains of superabrasive material. 
     
     
         5 . The cutting element of  claim 4 , wherein the shortest distance between walls defining the passageway is between about 0.025 mm and about 1 mm. 
     
     
         6 . The cutting element of  claim 1 , wherein a terminal end of the passageway is located within the cutting table. 
     
     
         7 . The cutting element of  claim 1 , wherein a minimum distance between an opening of the passageway at the exterior of the cutting table and a lateral side surface of the cutting table, as measured in a direction perpendicular to a longitudinal axis of the cutting element, is between about 5% and about 30% of a maximum width of the cutting table, as measured in the same direction. 
     
     
         8 . The cutting element of  claim 1 , wherein the distance between the exterior of the cutting table and the boundary between the first region and the second region varies with radial distance from the longitudinal axis, with angular distance around the longitudinal axis, or both. 
     
     
         9 . The cutting element of  claim 1 , wherein the second region is rotationally symmetrical about the longitudinal axis, reflectively symmetrical about at least one plane intersecting the longitudinal axis, or both. 
     
     
         10 . An earth-boring tool, comprising:
 a cutting element secured to a body, the cutting element comprising:
 a cutting table secured to a substrate, the cutting table comprising:
 a first region at least substantially free of solid infiltrant material in interstitial spaces among interbonded grains of superabrasive material located proximate a cutting face of the cutting table; 
 a second region comprising solid infiltrant material in the interstitial spaces among the interbonded grains of the superabrasive material located proximate the substrate; and 
 a passageway extending from an exterior of the cutting table partially through the first region; and 
 wherein a distance between the exterior of the cutting table and a boundary between the first region and the second region, as measured from a major surface of the cutting table, is not constant. 
 
   
     
     
         11 . A method of making a cutting element for an earth-boring tool, comprising:
 placing a sacrificial material among grains of a superabrasive material;   exposing the grains of the superabrasive material and the sacrificial material to elevated temperature and pressure in a presence of a catalyst material, forming a cutting table including a polycrystalline, superabrasive material;   removing the sacrificial material and a portion of the catalyst material from a first region of the cutting table; and   leaving a remainder of the catalyst material in a second region of the cutting table.   
     
     
         12 . The method of  claim 11 , wherein placing the sacrificial material among the grains of the superabrasive material comprises placing a metal or metal alloy including 10% by weight or more rhenium among the grains of the superabrasive material. 
     
     
         13 . The method of  claim 12 , wherein placing the metal or metal alloy including 10% by weight or more rhenium among the grains of the superabrasive material comprises placing a tungsten-rhenium alloy or material mixture among the grains of the superabrasive material. 
     
     
         14 . The method of  claim 11 , wherein placing the sacrificial material among the grains of the superabrasive material comprises placing a wire, foil, or sheet of the sacrificial material among the grains of the superabrasive material. 
     
     
         15 . The method of  claim 14 , wherein placing the wire, foil, or sheet of the sacrificial material among the grains of the superabrasive material comprises placing a wire, foil, or sheet including one or more of bends, curves, and straight portions among the grains of the superabrasive material. 
     
     
         16 . The method of  claim 11 , wherein placing the sacrificial material among the grains of the superabrasive material comprises one or more ends of the sacrificial material adjacent to a wall of the mold and otherwise surrounding the sacrificial material in the grains of the superabrasive material. 
     
     
         17 . The method of  claim 11 , further comprising removing the sacrificial material at a greater rate than a rate at which the portion of the catalyst material is removed. 
     
     
         18 . The method of  claim 17 , further comprising removing the sacrificial material at a rate between about  5  times and about  25  times greater than a rate at which the portion of the catalyst material is removed. 
     
     
         19 . The method of  claim 11 , wherein removing the sacrificial material and the portion of the catalyst material comprises exposing the cutting table to a leaching agent. 
     
     
         20 . The method of  claim 11 , wherein the acts of removing the sacrificial material and the portion of the catalyst material from the first region and leaving the remainder of the catalyst material in the second region comprise rendering a distance between an exterior of the cutting table and a boundary between the first region and the second region, as measured from a major surface of the cutting table, non-constant.