Composite metal, cemented carbide bit construction

Abstract

A manufacturing method and drill bit having either a preformed steel powder blank or machined steel core and abrasion and erosion resistant material components attached thereon.

1 . A method of forming a bit body for an earth-boring rotary drill bit, the method comprising:
 providing a rotary drill bit body;   providing a green powder component being configured to form a region of a bit body for attachment to the drill bit body;   at least partially sintering the green unitary structure; and   attaching the finally sintered structure to a portion of the rotary drill bit body.   
     
     
         2 . The method of  claim 1 , wherein the component comprises a shell for the rotary drill bit. 
     
     
         3 . The method of  claim 1 , wherein the component comprises a segment for attachment to a blade of the rotary drill bit. 
     
     
         4 . The method of  claim 1 , wherein the drill bit body comprises a first material. 
     
     
         5 . The method of  claim 4 , wherein the first material comprises one of steel or an alloy thereof. 
     
     
         6 . The method of  claim 4 , wherein the green powder component comprises a second material. 
     
     
         7 . The method of  claim 6 , wherein the first green powder component is configured to form a crown region of the bit body comprising:
 a plurality of particles comprising a matrix material, the matrix material selected from the group consisting of cobalt-based alloys, iron-based alloys, nickel-based alloys, cobalt and nickel-based alloys, iron and nickel-based alloys, iron and cobalt-based alloys, aluminum-based alloys, copper-based alloys, magnesium-based alloys, and titanium-based alloys; and   a plurality of hard particles selected from the group consisting of diamond, boron carbide, boron nitride, aluminum nitride, and carbides or borides of the group consisting of W, Ti, Mo, Nb, V, Hf, Zr, and Cr.   
     
     
         8 . The method of  claim 1 , wherein providing a plurality of green powder components comprises:
 providing a powder mixture; and   isostatically pressing the powder mixture.   
     
     
         9 . The method of  claim 1 , wherein at least partially sintering the green unitary structure comprises:
 partially sintering the green unitary structure to form a brown unitary structure;   machining at least one feature in the brown unitary structure; and   sintering the brown unitary structure to a desired final density.   
     
     
         10 . A method of forming a bit body for an earth-boring rotary drill bit, the method comprising:
 providing a rotary drill bit body;   providing a green powder component configured to form one of a crown region of a rotary drill bit body or a segment for attachment to the rotary drill bit body;   at least partially sintering the green powder component to form a brown component;   assembling the brown component to form a brown unitary structure; and   sintering the brown unitary structure to a final density.   
     
     
         11 . The method of  claim 10 , wherein providing a green powder component comprises:
 providing a first green powder component having a first composition.   
     
     
         12 . The method of  claim 10 , wherein sintering the brown unitary structure to a final density comprises subliquidus phase sintering. 
     
     
         13 . The method of  claim 10 , wherein sintering the brown unitary structure to a final density comprises subjecting the brown unitary structure to elevated temperatures in a vacuum furnace. 
     
     
         14 . A method of forming an earth-boring rotary drill bit, the method comprising:
 providing a bit body substantially formed of a steel composite material having a shank configured for attachment to a drill string;   providing another portion for attachment to the bit body comprising:
 providing a powder mixture comprising:
 a plurality of hard particles selected from the group consisting of diamond, boron carbide, boron nitride, aluminum nitride, and carbides or borides of the group consisting of W, Ti, Mo, Nb, V, Hf, Zr, and Cr; and 
 a plurality of particles comprising a matrix material, the matrix material selected from the group consisting of cobalt-based alloys, iron-based alloys, nickel-based alloys, cobalt and nickel-based alloys, iron and nickel-based alloys, iron and cobalt-based alloys, aluminum-based alloys, copper-based alloys, magnesium-based alloys, and titanium-based alloys; 
 
 pressing the powder mixture to form a green another portion for attachment to the bit body; and 
 at least partially sintering the green another portion for attachment to the bit body; and attaching the another portion to the bit body. 
   
     
     
         15 . The method of  claim 14 , wherein the matrix material is selected from the group consisting of cobalt-based alloys and cobalt and nickel-based alloys. 
     
     
         16 . The method of  claim 14 , wherein providing another portion for attachment to the bit body further comprises:
 machining at least one feature of the another portion.   
     
     
         17 . The method of  claim 16 , wherein machining at least one feature in the another portion comprises machining at least one of a fluid passageway, a junk slot, and a cutter pocket in the another portion. 
     
     
         18 . The method of  claim 14 , wherein at least partially sintering the green another portion for attachment to the bit body comprises:
 partially sintering the green another portion to form a brown another portion;   machining at least one feature in the brown another portion; and   sintering the brown another portion to a final density.   
     
     
         19 . The method of  claim 18 , wherein machining at least one feature in the brown another portion comprises machining at least one of a fluid passageway, a junk slot, and a cutter pocket in the brown another portion. 
     
     
         20 . The method of  claim 18 , wherein sintering the brown another portion to a final density comprises subliquidus phase sintering. 
     
     
         21 . The method of  claim 18 , wherein sintering the brown another portion to a final density comprises subjecting the brown another portion to elevated temperatures in a vacuum furnace. 
     
     
         22 . The method of  claim 21 , wherein sintering the brown another portion to a final density further comprises subjecting the brown another portion to substantially isostatic pressure after subjecting the brown bit body to elevated temperatures in a vacuum furnace. 
     
     
         23 . The method of  claim 14 , wherein pressing the powder mixture comprises pressing the powder mixture with substantially isostatic pressure. 
     
     
         24 . The method of  claim 23 , wherein pressing the powder mixture with substantially isostatic pressure comprises pressing the powder mixture with a liquid. 
     
     
         25 . The method of  claim 23 , wherein pressing the powder mixture with substantially isostatic pressure comprises pressing the powder mixture with substantially isostatic pressure greater than about 35 megapascals (about 5,000 pounds per square inch). 
     
     
         26 . The method of  claim 23 , wherein pressing the powder mixture comprises:
 providing the powder mixture in a bag comprising a polymer material; and   applying substantially isostatic pressure to exterior surfaces of the bag.   
     
     
         27 . The method of  claim 14 , wherein providing a powder mixture comprises providing a plurality of −400 ASTM mesh tungsten carbide particles, the plurality of tungsten carbide particles comprising between about 60% and about 95% by weight of the powder mixture. 
     
     
         28 . The method of  claim 14 , providing a powder mixture comprises
 providing a plurality of tungsten carbide particles having an average diameter in a range extending from about 0.5 microns to about 20 microns, the plurality of tungsten carbide particles comprising between about 75% and about 85% by weight of the powder mixture; and   providing a plurality of particles comprising the matrix material.   
     
     
         29 . The method of  claim 28 , wherein providing a mixture comprises:
 providing a plurality of tungsten carbide particles having an average diameter in a range extending from about 0.5 microns to about 20 microns, the plurality of tungsten carbide particles comprising between about 65% and about 70% by weight of the powder mixture; and   providing a plurality of particles comprising the matrix material.   
     
     
         30 . The method of  claim 14 , further comprising applying a hardfacing material to a surface of one of the bit body and the another portion. 
     
     
         31 . The method of  claim 30 , wherein applying a hardfacing material comprises one of flame spraying the hardfacing material, cold spraying the hardfacing material, oxy-acetylene welding (OA) material, atomic hydrogen welding (AHW) material, and plasma transfer arc welding (PTAW) material onto the surface of one of the bit body and the another portion. 
     
     
         32 . The method of  claim 31 , wherein applying a hardfacing material comprises:
 applying a fabric comprising tungsten carbide to the surface of one of the bit body and the another portion; and   infusing molten matrix material into the fabric comprising tungsten carbide.   
     
     
         33 . The method of  claim 14 , wherein the another portion comprises one of a shell for the bit body and a segment portion for the bit body. 
     
     
         34 . A drill bit comprising:
 a body having at least one blade comprising a first material; and   a shell formed of a second material different than the first material attached to the body.   
     
     
         35 . The drill bit of  claim 34 , wherein the shell comprises:
 a powder mixture comprising:   a plurality of hard particles selected from the group consisting of diamond, boron carbide, boron nitride, aluminum nitride, and carbides or borides of the group consisting of W, Ti, Mo, Nb, V, Hf, Zr, and Cr; and   a plurality of particles comprising a matrix material, the matrix material selected from the group consisting of cobalt-based alloys, iron-based alloys, nickel-based alloys, cobalt and nickel-based alloys, iron and nickel-based alloys, iron and cobalt-based alloys, aluminum-based alloys, copper-based alloys, magnesium-based alloys, and titanium-based alloys.   
     
     
         36 . The drill bit of  claim 35 , wherein the matrix material is selected from the group consisting of cobalt-based alloys and cobalt and nickel-based alloys. 
     
     
         37 . The drill bit of  claim 36 , wherein providing a powder mixture comprises providing a plurality of −400 ASTM mesh tungsten carbide particles, the plurality of tungsten carbide particles comprising between about 60% and about 95% by weight of the powder mixture. 
     
     
         38 . The method of  claim 36 , wherein the powder mixture comprises:
 a plurality of tungsten carbide particles having an average diameter in a range extending from about 0.5 microns to about 20 microns, the plurality of tungsten carbide particles comprising between about 75% and about 85% by weight of the powder mixture.   
     
     
         39 . A drill bit comprising:
 a body having at least one blade having a front face, an edge, and a rear face comprising a first material having at least one aperture formed in a portion thereof; and   a segment formed of a second material different than the first material attached to a portion of the blade of the body.   
     
     
         40 . The drill bit of  claim 39 , wherein the segment includes a protrusion located in a portion of the at least one aperture of the blade. 
     
     
         41 . The drill bit of  claim 39 , wherein the segment extends around a portion of the front face, a portion of the edge, and a portion of the rear face of the blade.