Hardfacing materials with highly conforming properties

Abstract

An earth-boring bit, and a method of increasing the durability of the same, which includes the step providing a pliable sheet of a hardfacing matrix material. The pliable sheet of hardfacing material has a nickel and chromium matrix combined with a first element. The first element is selected from a group consisting of spherical sintered tungsten carbide, spherical cast tungsten carbide, and metallic glass. The hardfacing matrix material sheet is placed on a preselected surface of the drill bit. The hardfacing matrix material sheet is then fusion bonded to the drill bit.

1 . A method of increasing the durability of a drill bit, comprising: 
 (a) providing a pliable sheet of a hardfacing matrix material comprising a nickel and chromium matrix combined with a first element selected from a group consisting of spherical sintered tungsten carbide, spherical cast tungsten carbide, and metallic glass;    (b) placing the hardfacing matrix material sheet on a preselected surface of the drill bit; and    (c) fusion bonding the hardfacing matrix material sheet to the drill bit.    
   
   
       2 . The method of  claim 1 , wherein step (c) is performed by heating the drill bit and hardfacing matrix material sheet in a furnace at about 2100 degrees Fahrenheit.  
   
   
       3 . The method of  claim 1 , wherein step (c) is performed by heating the drill bit and hardfacing matrix material sheet in a furnace at about 2100 degrees Fahrenheit for a duration of between about five minutes and about ten minutes.  
   
   
       4 . The method of  claim 1 , wherein in step (b), an adhesive located on a surface of the hardfacing matrix material sheet secures the hardfacing matrix material sheet in place relative to the preselected surface of the drill bit prior to step (c).  
   
   
       5 . The method of  claim 1 , wherein the preselected surface comprises an outer gage surface.  
   
   
       6 . The method of  claim 1 , wherein the preselected surface comprises a slot surface between a pair of bit blades.  
   
   
       7 . The method of  claim 1 , wherein the hardfacing matrix material further comprises a second element, which was not previously selected as the first element, selected from a group consisting of spherical sintered tungsten carbide, spherical cast tungsten carbide, metallic glass, microcrystalline tungsten carbide and macrocrystalline tungsten carbide.  
   
   
       8 . The method of  claim 7 , wherein the hardfacing matrix material further comprises a third element, which was not previously selected as either the first or second elements, selected from a group consisting of spherical sintered tungsten carbide, spherical cast tungsten carbide, metallic glass, microcrystalline tungsten carbide and macrocrystalline tungsten carbide.  
   
   
       9 . The method of  claim 1 , wherein the drill bit is a drag bit.  
   
   
       10 . The method of  claim 1 , wherein the drill bit is a tri-cone bit.  
   
   
       11 . A method of increasing the durability of a drag bit type of drill bit, the drag bit having a plurality of blades and a slot formed between each pair of adjacent blades, each of the blades having a cutting region with cutting elements and a gage surface free of cutting elements, the method comprising: 
 (a) providing a sheet of a hardfacing matrix material comprising a nickel and chromium matrix combined with a first element selected from a group consisting of spherical sintered tungsten carbide, spherical cast tungsten carbide, and metallic glass;    (b) cutting the sheet of a hardfacing matrix material into a pattern corresponding to a preselected surface of the drag bit;    (c) adhering the pattern to the preselected surface of the drag bit; and    (d) heating the drill bit, with the pattern adhered thereto, in order to bond the pattern to the drag bit.    
   
   
       12 . The method of  claim 11 , wherein the preselected surface comprises the gage surface.  
   
   
       13 . The method of  claim 11 , wherein the preselected surface comprises the gage surface and the slot.  
   
   
       14 . The method of  claim 11 , wherein the hardfacing matrix material further comprises a second element, which was not previously selected as the first element, selected from a group consisting of spherical sintered tungsten carbide, spherical cast tungsten carbide, metallic glass, microcrystalline tungsten carbide and macrocrystalline tungsten carbide.  
   
   
       15 . The method of  claim 14 , wherein the hardfacing matrix material further comprises a third element, which was not previously selected as either the first or second elements, selected from a group consisting of spherical sintered tungsten carbide, spherical cast tungsten carbide, metallic glass, microcrystalline tungsten carbide and macrocrystalline tungsten carbide.  
   
   
       16 . An earth-boring bit comprising: 
 a bit body having a bit face at its lower end and a nozzle opening to the bit face for discharging drilling fluid from an interior of the bit body;    a plurality of blades formed on and protruding from the bit face that extends radially outward from a central portion of the bit face to a gage area at the periphery of the bit body, each blade carrying a plurality of cutters thereon, and each pair of blades defining a slot extending therebetween for the passage of drilling fluid and cuttings;    a layer of hardfacing material being bonded to a surface of the bit body, the hardfacing material being substantially uniform in thickness and free of weldbeads, the hardfacing material comprising a nickel and chromium matrix combined with a first element selected from a group consisting of spherical sintered tungsten carbide, spherical cast tungsten carbide, and metallic glass; and    a bond region located between the layer of hardfacing material and the surface of the bit body to which the layer of hardfacing material is bonded.    
   
   
       17 . The earth-boring bit of  claim 16 , wherein the bond region comprises nickel and chromium from the layer of hardfacing and iron from the bit body, the bond region being formed when the layer of hardfacing is bonded to the surface of the bit body with heat.  
   
   
       18 . The earth-boring bit of  claim 16 , wherein the surface of the bit body to which the layer of hardfacing is bonded is the gage surface.  
   
   
       19 . The earth-boring bit of  claim 16 , wherein the surface of the bit body to which the layer of hardfacing is bonded is the slot.  
   
   
       20 . The earth-boring bit of  claim 16 , wherein the surface of the bit body to which the layer of hardfacing is within the nozzle.