Sacrificial Catalyst Polycrystalline Diamond Element

Abstract

A superhard composite material comprising a polycrystalline diamond cutter (PDC) having a cutting surface and cutting edges having a polycrystalline diamond thickness of about 3 mm is integrally formed with a sacrificial catalyst source that is removed later in the processing of the of the cutter.

1 . A superhard composite material comprising a polycrystalline diamond cutting element comprising a cutting surface with a finished polycrystalline diamond thickness of between about 2 mm and about 5 mm and comprising a high-temperature, high-pressure in-situ formed cemented carbide substrate that is integrally bonded to the PCD. 
     
     
         2 . The superhard composite material of  claim 1  further comprising a can and a lid for the HTHP component assembly with a shrink factor of about 1.10 for minimal OD grinding, and the thickness of the in-situ formed cemented carbide substrate is between about 6 and 20 mm. 
     
     
         3 . The superhard composite material of  claim 1  wherein a cobalt catalyst for Diamond-Diamond particle sintering and WC-WC cementation is supplied by a sacrificial cemented carbide substrate with an average grain size of 20 μm and cobalt of 35 wt %. 
     
     
         4 . The superhard composite material of  claim 3  wherein the finished cutter is about 1613 mm in diameter. 
     
     
         5 . The superhard composite material of  claim 3  wherein the sacrificial substrate in contact with the diamond particle forms a conic bevel at an outside diameter to form an in-situ chamfer on the PCD after HTHP processing. 
     
     
         6 . The superhard composite material of  claim 5  wherein the diamond feed stock is a mono modal size of about 50μ. 
     
     
         7 . The superhard composite material of  claim 5  wherein the WC particle size in contact with the diamond particle is a mono modal size of about 50 μm. 
     
     
         8 . The superhard composite material of  claim 5  wherein a transition Diamond—WC layer is formed by using a probing tool that is used to selectively transfer WC particle into the diamond particle bed to a depth of about 1 mm. 
     
     
         9 . The superhard composite material of  claim 2  wherein the can and lid mechanically sealed. 
     
     
         10 . The superhard composite material of  claim 2 , wherein the can is exposed to a HTHP process to enable composite densification aided via a catalyst infiltration from the cemented carbide substrate into the diamond and WC particle bed, wherein the cemented carbide substrate is a sacrificial substrate, and wherein the HTHP processing is at least 40 kbar pressures and the temperature is at least 1000° C. 
     
     
         11 . The superhard composite material of  claim 2 , wherein the sweep or movement of the catalyst during HTHP processing occurs from the top of the PCD surface to the bottom of the in-situ formed substrate. 
     
     
         12 . The superhard composite material of  claim 11  wherein after HTHP processing, the super hard composite is finished by removal of the can/sacrificial substrate and OD grinding. 
     
     
         13 . The superhard composite material of  claim 11  wherein the sacrificial substrate is formed of a metal carbide selected from the group consisting of a tungsten carbide, titanium carbide, tantalum carbide, and mixtures thereof. 
     
     
         14 . The superhard composite material of  claim 13  wherein the sacrificial substrate is formed of a carbide from the group of IVB, VB, or VIB metals which is pressed and sintered in the presence of a binder of cobalt, nickel, iron, and alloys thereof, and further comprises:
 an average carbide particle size greater than >3 μm, 
 a weight % Binder >3, 
 a binder comprising Co, Ni, or Fe with at least 5 wt % Co in the sacrificial binder phase. 
 
     
     
         15 . The superhard composite material of  claim 14  wherein WC is replaced with MC comprising M=V, Mo, Ti, Ta) and mixes thereof with a WC content of at least 5 wt %. 
     
     
         16 . The superhard composite of  claim 15  wherein the sacrificial binder substrate that has M, C, Co (Fe, Ni) a eutectic composition forming 100% melt at the eutectic temperature; W, C, Co—Ni eutectic temperate is about 1270 degrees C. 
     
     
         17 . The superhard composite material of  claim 1  wherein a surface texture of the sacrificial substrate in contact with the diamond particle comprises:
 a surface texture on the substrate is the negative of the desired roughness on the cutting element face, and 
 the texture is formed by pressing the grade mix or post sintered operations including laser, EDM or other methods for providing the texture. 
 
     
     
         18 . The superhard composite material of  claim 17  wherein the texture can have chip breaker geometries used for milling and turning inserts to aid with chipping of formation. 
     
     
         19 . The superhard composite of  claim 1  wherein the Diamond particles have a multi-modal size distribution for optimal packing with a size range of 1 nm to 100 μm, and the diamond particles have a carbon phase additive >5 wt % that is amorphous or nano structure fullerenes. 
     
     
         20 . The superhard composite of  claim 19  wherein the diamond particles are replaced with CBN particles. 
     
     
         21 . The superhard composite of  claim 20  further comprising a mixture of Diamond and CBN particles comprising at least 0.5 wt % diamond particles. 
     
     
         22 . The superhard composite of  claim 1  wherein the interface probing depth may be 100% of the PCD layer with a low WC concentration near a sacrificial substrate and a high concentration near the WC-diamond interface. 
     
     
         23 . The superhard composite of  claim 1  wherein the WC content in diamond particle bed ranges at the preformed interface ranges from 1 wt % to 80 wt %. 
     
     
         24 . The superhard composite of  claim 1  wherein the Carbide particles are formed of a metal carbide selected from the group consisting of tungsten carbide, titanium carbide, tantalum carbide, and mixtures thereof from the group of IVB, VB, or VIB metals, and comprising a multi modal particle size distribution for optimal packing with a size range of 1 nm to 100 μm,
 wherein at least 5 wt % of the particles are >50 μm to ensure adequate erosion resistance of the HTHP in-situ formed substrate. 
 
     
     
         25 . The superhard composite of  claim 1  wherein the diamond particles, interface and WC particle bed are preforms manufactured using a fugitive binder like PEG, mineral oil and methyl cellulose to limit segregation during transfer to the can, wherein, a moldable diamond mix is pressed in the can to conform to the sacrificial substrate texture,
 an interface is formed by using a probing tool to transfer a given amount of WC mix into the diamond mix, 
 a WC mix is pressed into the can above the interface, and 
 the fugitive binder is removed in the presence of hydrogen. 
 
     
     
         26 . The superhard composite of  claim 1  comprising a sink for a catalyst abridging the WC bed to reduce catalyst content in the densified PCD/substrate wherein
 the sink comprises loose Zirconia ceramic particles and the like, that have greater resistance to HTHP sintering than WC particles in the presence of said catalyst, and wherein the sink is removed after HTHP processing via a EDM, laser or abrasive cutting. 
 
     
     
         27 . The superhard composite of  claim 1  wherein substrate removal is by a mechanical dry/wet abrasives grinding or chemical leaching or a combination of both methods. 
     
     
         28 . The superhard composite of  claim 1  wherein the PCD face is coated with a nano coating diamond or diamond like coating. 
     
     
         29 . The superhard composite of  claim 1  wherein that the said cutter shape has a irregular cross section or symmetric cross section such as an oval, triangular, or a trapezoidal shape. 
     
     
         30 . The superhard composite of  claim 1  wherein the composite tool has a typical geometry for cutting and milling inserts. 
     
     
         31 . The superhard composite of  claim 1  wherein the composite tool has a typical geometry of inserts used for rolling cutter earth boring drill bits.