Metal-infiltrated polycrystalline diamond composite tool formed from coated diamond particles

Abstract

A metal-infiltrated polycrystalline diamond composite tool comprising a plurality of diamond grains forming a continuous polycrystalline diamond matrix, a metallic phase being substantially palladium-free and contiguous to the continuous polycrystalline diamond matrix, wherein the metallic phase interpenetrates the continuous polycrystalline diamond matrix and substantially wets an outer surface of the continuous polycrystalline diamond matrix; and a working surface. The metallic phase is formed from an infiltrant and a wetting-enhancement layer disposed on the outer surfaces of the diamond particles, with both the infiltrant and wetting-enhancement layer being substantially palladium-free and comprising at least one metal from the group consisting of cobalt, iron, and nickel. The invention also includes a preform for a metal-infiltrated polycrystalline diamond composite tool, the perform comprising a container, a metallic infiltrant source, and a plurality of coated diamonds, each coated with a wetting-enhancement layer and, optionally, an activation layer, both of which are substantially palladium-free. Methods of forming the metal-infiltrated polycrystalline diamond composite tool, the preform, and the coated diamond particles used in the tool are also disclosed.

What is claimed is:  
     
         1 . A metal-infiltrated polycrystalline diamond composite tool, said metal-infiltrated polycrystalline diamond tool comprising: 
 a) a plurality of diamond grains, said plurality of diamond grains forming a continuous polycrystalline diamond matrix;    b) a metallic phase, said metallic phase being substantially palladium-free and contiguous to said continuous polycrystalline diamond matrix, wherein said metallic phase interpenetrates the continuous polycrystalline diamond matrix and substantially wets an outer surface of said continuous polycrystalline diamond matrix; and    c) a working surface.    
     
     
         2 . The metal-infiltrated polycrystalline diamond composite tool of  claim 1 , wherein said working surface comprises an abrasive surface.  
     
     
         3 . The metal-infiltrated polycrystalline diamond composite tool of  claim 1 , wherein said metallic phase comprises at least one metal selected from the group consisting of cobalt, iron, and nickel.  
     
     
         4 . The metal-infiltrated polycrystalline diamond composite tool of  claim 3 , wherein said metallic phase comprises cobalt.  
     
     
         5 . The metal-infiltrated polycrystalline diamond composite tool of  claim 3 , wherein said metallic phase further comprises at least one element selected from the group consisting of phosphorus, tin, and boron.  
     
     
         6 . The metal-infiltrated polycrystalline diamond composite tool of  claim 1 , wherein said metallic phase further comprises at least one metal selected from the group consisting of silver, copper, gold, platinum, and combinations thereof.  
     
     
         7 . The metal-infiltrated polycrystalline diamond composite tool of  claim 1 , wherein each of said plurality of diamond grains has an average diameter between about 0.0001 mm and about 1 mm.  
     
     
         8 . The metal-infiltrated polycrystalline diamond composite tool of  claim 7 , wherein each of said plurality of diamond grains has an average diameter between about 10 microns and about 100 microns.  
     
     
         9 . The metal-infiltrated polycrystalline diamond composite tool of  claim 1 , further including a support layer disposed on a surface of said metal-infiltrated polycrystalline diamond composite tool opposite said working surface, said support layer comprising a continuous matrix formed by a plurality of hard particles and said metallic phase interpenetrating said continuous matrix.  
     
     
         10 . The metal-infiltrated polycrystalline diamond composite tool of  claim 9 , wherein each of said plurality of hard particles comprises at least one metal carbide selected from the group consisting of niobium carbide, silicon carbide, titanium carbide, tungsten carbide, zirconium carbide, and combinations thereof.  
     
     
         11 . The metal-infiltrated polycrystalline diamond composite tool of  claim 10 , wherein each of said plurality of hard particles comprises tungsten carbide.  
     
     
         12 . The metal-infiltrated polycrystalline diamond composite tool of  claim 1 , wherein said continuous polycrystalline diamond matrix comprises between about 85 and about 95 volume percent of said metal-infiltrated polycrystalline diamond composite tool.  
     
     
         13 . The metal-infiltrated polycrystalline diamond composite tool of  claim 2 , wherein said metal-infiltrated polycrystalline diamond composite tool is a tool selected from the group consisting of cutting tool blanks, wire dies, and drill blanks.  
     
     
         14 . A preform for a metal-infiltrated polycrystalline diamond composite tool, said preform comprising: 
 a) a container formed from a refractory material;    b) a plurality of coated diamond particles disposed in said container and forming a bed therein, each of said plurality of coated diamond particles comprising a diamond having an outer surface and a wetting-enhancement coating disposed thereon, said wetting-enhancement coating being substantially palladium-free and comprising at least one metal selected from the group consisting of cobalt, iron, and nickel, wherein said wetting-enhancement coating substantially covers said outer surface; and    c) a metallic infiltrant source disposed in said container and contacting said bed of said plurality of coated diamond particles, said metallic infiltrant source comprising at least one metal selected from the group consisting of cobalt, iron, and nickel.    
     
     
         15 . The preform of  claim 14 , wherein said outer surface is a sensitized surface formed by contacting an aqueous solution containing a sensitizer with said outer surface, and wherein each of said plurality of coated diamond particles further comprises an activation layer disposed between said sensitized surface and said wetting-enhancement coating, said activation layer being substantially palladium-free.  
     
     
         16 . The preform of  claim 15 , wherein said sensitizer comprises a salt of a sensitizing metal, wherein said sensitizing metal is a metal selected from the group consisting of manganese, iron, cobalt, nickel, copper, cadmium, and tin.  
     
     
         17 . The preform of  claim 16 , wherein said sensitizing metal is tin.  
     
     
         18 . The preform of  claim 17 , wherein said sensitizer is tin dichloride.  
     
     
         19 . The preform of  claim 15 , wherein said activation layer comprises a metal selected from the group consisting of silver, gold, platinum, cobalt, and copper.  
     
     
         20 . The preform of  claim 15 , wherein said wetting-enhancement coating further includes an element selected from the group consisting of tin, phosphorus and boron.  
     
     
         21 . The preform of  claim 20 , wherein said wetting-enhancement coating comprises cobalt.  
     
     
         22 . The preform of  claim 21 , wherein said wetting-enhancement coating further comprises boron.  
     
     
         23 . The preform of  claim 22 , wherein boron comprises up to about 30 weight percent of said wetting-enhancement coating.  
     
     
         24 . The preform of  claim 23 , wherein boron comprises up to about 3 weight percent of said wetting-enhancement coating.  
     
     
         25 . The preform of  claim 21 , wherein said wetting-enhancement coating has a thickness of about 0.01 to 5 microns.  
     
     
         26 . The preform of  claim 21 , wherein said wetting-enhancement coating is a cobalt bearing precipitate.  
     
     
         27 . The preform of  claim 21 , wherein said wetting-enhancement coating is a cobalt bearing colloidal deposit.  
     
     
         28 . The preform of  claim 14 , wherein said wetting-enhancement coating is a vapor-deposited coating.  
     
     
         29 . The preform of  claim 15 , wherein said activation layer comprises between about 0.01 weight percent and about 10 weight percent of said coated diamond particle.  
     
     
         30 . The preform of  claim 15 , wherein said activation layer is a precipitate.  
     
     
         31 . The preform of  claim 15 , wherein said activation layer is a colloidal deposit.  
     
     
         32 . The preform of  claim 14 , wherein said metallic infiltrant source further comprises a continuous matrix formed by a plurality of hard particles.  
     
     
         33 . The preform of  claim 32 , wherein each of said plurality of hard particles comprises at least one metal carbide selected from the group consisting of niobium carbide, silicon carbide, titanium carbide, tungsten carbide, zirconium carbide, and combinations thereof.  
     
     
         34 . The preform of  claim 33 , wherein each of said plurality of hard particles comprises tungsten carbide.  
     
     
         35 . A metal-infiltrated polycrystalline diamond composite tool formed from a preform, said preform comprising: a container formed from a refractory material; a plurality of coated diamond particles disposed in said container and forming a bed therein, each of said plurality of coated diamond particles comprising a diamond having an outer surface and a wetting-enhancement coating disposed thereon, said wetting-enhancement coating being substantially palladium-free and comprising a metal selected from the group consisting of cobalt, iron, and nickel, wherein said wetting-enhancement coating substantially covers said outer surface; and a metallic infiltrant source contacting said bed of said plurality of coated diamond particles, said metal-infiltrated polycrystalline diamond composite tool comprising: 
 a) a plurality of diamond grains, said plurality of diamond grains forming a continuous polycrystalline diamond matrix;    b) a metallic phase, said metallic phase being substantially palladium-free and contiguous to continuous polycrystalline diamond matrix, wherein said metallic phase interpenetrates said continuous polycrystalline diamond matrix and substantially wets an outer surface of said continuous polycrystalline diamond matrix; and wherein said metallic phase comprises at least one metal selected from the group consisting of cobalt, iron, and nickel; and    c) an abrasive working surface.    
     
     
         36 . The metal-infiltrated polycrystalline diamond composite tool of  claim 35 , wherein said metallic phase comprises cobalt.  
     
     
         37 . The metal-infiltrated polycrystalline diamond composite tool of  claim 35 , wherein said metallic phase further comprises at least one metal selected from the group consisting of silver, copper, gold, platinum, and combinations thereof.  
     
     
         38 . The metal-infiltrated polycrystalline diamond composite tool of  claim 35 , wherein said metallic phase further comprises at least one element selected from the group consisting of phosphorus, tin, and boron.  
     
     
         39 . The metal-infiltrated polycrystalline diamond composite tool of  claim 35 , wherein each of said plurality of diamond grains has an average diameter between about 0.0001 mm and about 1 mm.  
     
     
         40 . The metal-infiltrated polycrystalline diamond composite tool of  claim 39 , wherein each of said plurality of diamond grains has an average diameter between about 10 microns and about 100 microns.  
     
     
         41 . The metal-infiltrated polycrystalline diamond composite tool of  claim 35 , further including a support layer disposed on a surface of said metal-infiltrated polycrystalline diamond composite tool opposite said abrasive working surface, said support layer comprising a continuous matrix formed by a plurality of hard particles and said metallic phase interpenetrating said continuous matrix.  
     
     
         42 . The metal-infiltrated polycrystalline diamond composite tool of  claim 40 , wherein each of said plurality of hard particles comprises at least one metal carbide selected from the group consisting of niobium carbide, silicon carbide, titanium carbide, tungsten carbide, zirconium carbide, and combinations thereof.  
     
     
         43 . The metal-infiltrated polycrystalline diamond composite tool of  claim 41 , wherein each of said plurality of hard particles comprises tungsten carbide.  
     
     
         44 . The metal-infiltrated polycrystalline diamond composite tool of  claim 35 , wherein said metal-infiltrated polycrystalline diamond composite tool is a tool selected from the group consisting of cutting tool blanks, wire dies, and drill blanks.  
     
     
         45 . The metal-infiltrated polycrystalline diamond composite tool of  claim 35 , wherein said continuous polycrystalline diamond matrix comprises between about 85 and about 95 volume percent of said metal-infiltrated polycrystalline diamond composite tool.  
     
     
         46 . A method of making a metal-infiltrated polycrystalline diamond composite tool, wherein the metal-infiltrated polycrystalline diamond composite tool comprises: a plurality of diamond grains forming a continuous polycrystalline diamond matrix; a metallic phase being substantially palladium-free and contiguous to the continuous polycrystalline diamond matrix, wherein the metallic phase interpenetrates the continuous polycrystalline diamond matrix and substantially wets an outer surface of the continuous polycrystalline diamond matrix; and a working surface, the method comprising the steps of: 
 a) providing a preform, the preform comprising: a container containing a metallic infiltrant, the metallic infiltrant being substantially palladium-free, and a plurality of coated diamond particles, wherein each of the coated diamond particles comprises a diamond having an outer surface and a substantially palladium-free wetting-enhancement coating disposed thereon;    b) infiltrating the plurality of coated diamond particles with the metallic infiltrant and producing diamond-to-diamond bonding, thereby forming a metal-infiltrated polycrystalline diamond composite blank; and    c) forming a working surface on at least one surface of the metal-infiltrated polycrystalline diamond composite blank, thereby forming the metal-infiltrated polycrystalline diamond composite tool.    
     
     
         47 . The method of  claim 46 , wherein the step of providing a preform comprises the steps of: 
 a) providing a container formed from a refractory material;    b) providing a plurality of coated diamond particles to the container, each of the coated diamond particles comprising a diamond having an outer surface and a substantially palladium-free wetting-enhancement coating disposed thereon; and    c) providing a substantially palladium-free metallic infiltrant source to the container such that the substantially palladium-free metallic infiltrant source contacts the plurality of coated diamond particles.    
     
     
         48 . The method of  claim 47 , wherein the step of providing a substantially palladium-free metallic infiltrant source to the container comprises providing a substantially palladium-free metallic infiltrant source comprising the metallic infiltrant and a continuous matrix formed by a plurality of hard particles to the container such that the substantially palladium-free metallic infiltrant source contacts the plurality of coated diamond particles.  
     
     
         49 . The method of  claim 46 , wherein the step of infiltrating the plurality of coated diamond particles with the metallic infiltrant comprises: 
 a) heating the preform to a predetermined temperature above the melting temperature of the metallic infiltrant;    b) melting the metallic infiltrant;    c) applying a predetermined pressure to the preform, thereby forcing the metallic infiltrant into free spaces between the plurality of coated diamond particles;    d) liquid-sintering the diamond particle, thereby forming diamond-to-diamond bonds, and    e) cooling the preform, thereby forming a metal-infiltrated polycrystalline diamond composite blank.    
     
     
         50 . The method of  claim 49 , wherein the step of heating the preform to a predetermined temperature above the melting temperature of the metallic infiltrant comprises heating the preform to a temperature between about 1300° C. and about 1700° C.  
     
     
         51 . The method of  claim 49 , wherein the step of applying a predetermined pressure to the preform comprises applying a pressure in the range of between about 40 kbar to about 70 kbar to the preform.  
     
     
         52 . The method of  claim 46 , wherein the metallic phase comprises at least one metal selected from the group consisting of cobalt, iron, and nickel.  
     
     
         53 . The method of  claim 46 , wherein the metallic infiltrant comprises at least one metal selected from the group consisting of cobalt, iron, and nickel.  
     
     
         54 . The method of  claim 47 , wherein the substantially palladium-free wetting-enhancement coating comprises at least one metal selected from the group consisting of cobalt, iron, and nickel.  
     
     
         55 . A method of making a coated diamond particle for use in a metal-infiltrated polycrystalline diamond composite tool, the method comprising the steps of: 
 a) providing a diamond; and    b) coating an outer surface of the diamond with a substantially palladium-free wetting-enhancement coating comprising at least one metal selected form the group consisting of cobalt, iron, and nickel, such that the substantially palladium-free wetting-enhancement coating substantially covers the outer surface, thereby forming a coated diamond particle.    
     
     
         56 . The method of  claim 55 , wherein the step of coating an outer surface of the diamond with a substantially palladium-free wetting-enhancement coating comprises the steps of: 
 a) sensitizing a surface of the diamond particle by contacting the surface with an aqueous sensitizer, thereby creating a sensitized surface;    b) depositing a substantially palladium-free activating layer on the sensitized surface of the diamond particle; and    c) depositing a substantially palladium-free wetting-enhancement coating comprising at least one metal selected from the group consisting of cobalt, iron, and nickel, such that the substantially palladium-free wetting-enhancement coating substantially covers the outer surface, thereby forming a coated diamond particle.    
     
     
         57 . The method of  claim 56 , wherein the step of sensitizing a surface of the diamond particle comprises the step of contacting the diamond particle with a solution of tin dichloride and hydrochloric acid.  
     
     
         58 . The method of  claim 57 , further including the steps of: 
 a) contacting the diamond particle with the solution of tin dichloride and hydrochloric acid at room temperature for about five minutes;    b) washing the diamond particle; and    c) drying the diamond particle.    
     
     
         59 . The method of  claim 56 , wherein the step of depositing a substantially palladium-free activating metal layer on the sensitized surface of the diamond particle comprises depositing a silver activating layer on the sensitized surface of the diamond particle.  
     
     
         60 . The method of  claim 59 , wherein the step of depositing a silver activating layer on the sensitized surface of the diamond particle comprises the steps of: 
 a) immersing the diamond particle in a silver nitrate solution for about five minutes at room temperature;    b) washing the diamond particle; and    c) drying the diamond particle.    
     
     
         61 . The method of  claim 56 , wherein the step of coating an outer surface of the diamond with a palladium-free wetting enhancement coating comprises the step of precipitating cobalt from an aqueous solution.  
     
     
         62 . The method of  claim 56 , wherein the step of coating an outer surface of the diamond with a palladium-free wetting enhancement coating comprises vapor depositing cobalt using a vapor deposition techniques selected from the group consisting of chemical vapor deposition, physical vapor deposition, plasma assisted chemical vapor deposition, and combinations thereof.  
     
     
         63 . A method of making a preform for a metal-infiltrated polycrystalline diamond composite tool, the method comprising the steps of: 
 a) providing a container formed from a refractory material;    b) providing a plurality of coated diamond particles to the container, each of the coated diamond particles comprising a diamond having an outer surface and a substantially palladium-free wetting-enhancement coating disposed thereon; and    c) providing a substantially palladium-free metallic infiltrant source to the container such that the substantially palladium-free metallic infiltrant source contacts the plurality of coated diamond particles.    
     
     
         64 . The method of  claim 63 , wherein the step of providing a substantially palladium-free metallic infiltrant source to the container comprises providing a substantially palladium-free metallic infiltrant source comprising a substantially palladium-free metallic infiltrant and a plurality of hard particles to the container such that the substantially palladium-free metallic infiltrant source contacts the plurality of coated diamond particles.  
     
     
         65 . The method of  claim 63 , wherein the substantially palladium-free wetting-enhancement coating comprises at least one metal selected from the group consisting of cobalt, iron, and nickel.  
     
     
         66 . The method of  claim 63 , wherein the substantially palladium-free metallic infiltrant source comprises at least one metal selected from the group consisting of cobalt, iron, and nickel.