Drill bit cutters and cutter assemblies

Abstract

A cutter for a drill bit includes a substrate defining a hole at least partially through the substrate. A diamond table including a protrusion is received within the hole such that a gap is defined between the protrusion and the substrate ranging between 0.001 and 0.010 inches when the substrate and diamond table are at standard temperature and pressure (STP). A braze alloy couples the diamond table to the substrate at an interface between the diamond table and the substrate. At least a portion of the braze alloy is disposed in the gap in compression between the protrusion on the diamond and the hole in the substrate.

What is claimed is: 
     
         1 . A cutter for a drill bit, the cutter comprising:
 a substrate defining a hole at least partially through the substrate;   a diamond table including a protrusion received within the hole such that a gap is defined between the protrusion and the substrate ranging between 0.001 and 0.010 inches when the substrate and diamond table are at standard temperature and pressure (STP); and   a braze alloy coupling the diamond table to the substrate at an interface between the diamond table and the substrate, wherein at least a portion of the braze alloy is disposed in the gap in compression between the protrusion on the diamond and the hole in the substrate.   
     
     
         2 . The cutter of  claim 1 , wherein the interface between the diamond table and the substrate further comprises a planar face about the protrusion on the diamond table in close engagement with a corresponding planar face about the hole on the substrate, and wherein another portion of the braze alloy secures the planar face of the diamond table to the planar face of the substrate. 
     
     
         3 . The cutter of  claim 1 , wherein the protrusion on the diamond table and the hole on the substrate are both circular, and the gap is a substantially constant-radial gap between the protrusion and the substrate. 
     
     
         4 . The cutter of  claim 1 , wherein the diamond table has a first coefficient of thermal expansion (CTE) and the substrate has a second CTE greater than the first CTE. 
     
     
         5 . The cutter of  claim 1 , wherein the diamond table comprises a plurality of protrusions. 
     
     
         6 . The cutter of  claim 1 , wherein the braze alloy remains in compression up to at least a solidus temperature of the braze alloy. 
     
     
         7 . The cutter of  claim 1 , further comprising one of a thermally conductive material and a temperature-sensitive material positioned in the hole at a location not occupied by the protrusion and the braze alloy. 
     
     
         8 . The cutter of  claim 7 , wherein the thermally conductive material or the temperature-sensitive material is in direct mechanical contact with an end of the protrusion. 
     
     
         9 . A cutter for a drill bit, the cutter comprising:
 a substrate defining a hole at least partially through the substrate;   a diamond table; and   a protrusion extending from the diamond table at least partially into the hole and in direct mechanical contact with the substrate via an interference fit between the protrusion and the substrate when at STP.   
     
     
         10 . The cutter of  claim 9 , wherein the diamond table defines the protrusion. 
     
     
         11 . The cutter of  claim 9 , wherein the protrusion comprises a post extending all the way through the hole on the substrate and having one end coupled to the diamond table and another end opposite the diamond table for coupling to a cutter pocket of a drill bit. 
     
     
         12 . The cutter of  claim 11 , wherein the diamond table comprises a hole aligned with the hole on the substrate, and wherein the post extends into the hole on the diamond table. 
     
     
         13 . The cutter of  claim 9 , further comprising a braze alloy between a planar face about the protrusion on the diamond table and a corresponding planar face about the hole on the substrate, wherein the braze alloy secures the planar face of the diamond table to the planar face of the substrate. 
     
     
         14 . A drill bit, comprising:
 a bit body having one or more blades extending therefrom; and   a plurality of cutters secured to the one or more blades, wherein at least one cutter of the plurality of cutters includes:
 a substrate defining a hole at least partially through the substrate; 
 a diamond table including a protrusion received within the hole such that a gap is defined between the protrusion and the substrate ranging between 0.001 and 0.010 inches when the substrate and diamond table are at standard temperature and pressure (STP); and 
 a braze alloy coupling the diamond table to the substrate at an interface between the diamond table and the substrate, wherein at least a portion of the braze alloy is disposed in the gap in compression between the protrusion on the diamond and the hole in the substrate. 
   
     
     
         15 . The drill bit of  claim 14 , wherein the interface between the diamond table and the substrate further comprises a planar face about the protrusion on the diamond table in close engagement with a corresponding planar face about the hole on the substrate, and wherein a braze alloy at the interface secures the planar face of the diamond table to the planar face of the substrate. 
     
     
         16 . The drill bit of  claim 14 , wherein the protrusion on the diamond table and the hole on the substrate are both circular, and the gap is a substantially constant-radial gap between the protrusion and the substrate. 
     
     
         17 . The drill bit of  claim 14 , wherein the diamond table has a first coefficient of thermal expansion (CTE) and the substrate has a second CTE greater than the first CTE. 
     
     
         18 . The drill bit of  claim 14 , wherein the compression on the braze alloy is maintained up to at least a solidus temperature of the braze alloy. 
     
     
         19 . The drill bit of  claim 14 , further comprising one of a thermally conductive material and a temperature-sensitive material positioned in the hole at a location not occupied by the protrusion and the braze alloy. 
     
     
         20 . The drill bit of  claim 14 , further comprising a post extending from a cutter pocket on the one or more blades and secured within the hole of the substrate.