Thermally stable polycrystalline ultrahard material reinforced with fibrous materials

Abstract

A polycrystalline diamond construction includes a diamond body having a thermally stable diamond matrix comprising bonded-together diamond crystals, wherein the diamond matrix includes a diamond volume content of at least 99%, and a plurality of fibers extending through the thermally stable diamond matrix. The diamond construction may be bonded to a substrate forming a shear cutter. The shear cutter may be mounted on a bit body.

What is claimed is: 
     
         1 . A polycrystalline diamond construction, comprising:
 a diamond body having a thermally stable diamond matrix comprising bonded-together diamond crystals, wherein the diamond matrix comprises a diamond volume content of at least 99%; and   a plurality of fibers extending through the thermally stable diamond matrix.   
     
     
         2 . The polycrystalline diamond construction of  claim 1 , wherein the fibers comprise a strain to failure greater than that of the diamond crystals. 
     
     
         3 . The polycrystalline diamond construction of  claim 1 , wherein the fibers comprise silicon carbide, alumina, sapphire, or magnesium aluminosilicate. 
     
     
         4 . The polycrystalline diamond construction of  claim 1 , wherein the fibers are oriented in a pre-determined orientation in the thermally stable diamond matrix. 
     
     
         5 . The polycrystalline diamond construction of  claim 1 , wherein the fibers are randomly oriented in the thermally stable diamond matrix. 
     
     
         6 . The polycrystalline diamond construction of  claim 1 , wherein the diamond crystals are thermally stable above 700° C. 
     
     
         7 . The polycrystalline diamond construction of  claim 1 , wherein the fibers comprise a coating providing an interface between the fibers and the diamond crystals that is weaker than the diamond matrix. 
     
     
         8 . The polycrystalline diamond construction of  claim 7 , wherein the coating comprises an oxide, carbide, or silicide material. 
     
     
         9 . The polycrystalline diamond construction of  claim 1 , wherein the plurality of fibers occupy about 5-30% by volume of the diamond body. 
     
     
         10 . The polycrystalline diamond construction of  claim 9 , wherein the thermally stable diamond matrix occupies the remaining 70-95% by volume of the diamond body. 
     
     
         11 . A shear cutter, comprising the polycrystalline diamond construction of  claim 1 , directly or indirectly bonded to a substrate. 
     
     
         12 . A drag bit comprising a body having the shear cutter of  claim 9 , mounted thereon. 
     
     
         13 . A method of forming a fiber-reinforced thermally stable polycrystalline diamond construction, comprising:
 providing a fiber matrix;   infiltrating the fiber matrix with graphite; and   HPHT sintering the graphite and the fiber matrix at ultra-high temperature and pressure, without a catalyst material.   
     
     
         14 . The method of  claim 13 , wherein HPHT sintering includes phase-transforming the graphite into polycrystalline diamond. 
     
     
         15 . The method of  claim 13 , wherein the ultra-high temperature and pressure comprise a temperature of about 1800-2500° C. and a pressure of about 100-160 kbar. 
     
     
         16 . The method of  claim 13 , further comprising orienting the fibers in a pre-determined orientation prior to infiltrating. 
     
     
         17 . The method of  claim 13 , further comprising randomly orienting the fibers prior to infiltrating. 
     
     
         18 . A polycrystalline diamond construction, comprising:
 a diamond body having a diamond matrix comprising bonded-together diamond crystals and interstitial spaces between the diamond crystals, and comprising a carbonate catalyst disposed within the interstitial spaces; and   a plurality of fibers extending through the diamond matrix.   
     
     
         19 . The diamond construction of  claim 18 , wherein the fibers are oriented in stacked layers in the diamond body. 
     
     
         20 . A shear cutter, comprising the polycrystalline diamond construction of  claim 18 , directly or indirectly bonded to a substrate. 
     
     
         21 . A drag bit comprising a body having the shear cutter of  claim 18 , mounted thereon.