Sintered superhard compact for cutting tool applications and method of its production

Abstract

A method and composition of a sintered superhard compact is provided. The sintered superhard compact body may comprise superhard particles and a binder phase. The binder phase may bond the superhard particles together. The binder phase comprises tungsten and cobalt. The ratio of tungsten to cobalt is between 1 and 2 and sum of W and Co in the sintered superhard compact is in a range of from about 2 to about 20 percent by weight.

We claim: 
     
         1 . A sintered superhard compact body, comprising:
 superhard particles; and   a binder phase bonding the superhard particles together, wherein the binder phase comprises W and Co, wherein the weight % ratio of W/Co in the sintered superhard compact falls between 1.0 and 2.0, and sum of weight % W and Co in the sintered superhard compact is in a range of from about 2.0 to about 20.   
     
     
         2 . The sintered superhard compact body of  claim 1 , wherein the superhard particles are selected from a group of cubic boron nitride, diamond, and diamond composite materials. 
     
     
         3 . The sintered superhard compact body of  claim 1 , further comprises stoichiometric carbides, nitrides, oxides, or sums thereof from aluminum, titanium or other metals in transition group IV, V, and VI in Periodic Table of elements. 
     
     
         4 . The sintered superhard compact body of  claim 1 , further comprises substoichiometric carbides, nitrides, oxides, or sums thereof from aluminum, titanium or other metals in transition group IV, V, and VI in Periodic Table of elements. 
     
     
         5 . The sintered superhard compact body of  claim 1 , wherein a ratio of tungsten to cobalt is in a range of from 1.0 to 1.8. 
     
     
         6 . The sintered superhard compact body of  claim 1 , wherein a ratio of tungsten to cobalt is in a range of from 1.0 to 1.5. 
     
     
         7 . The sintered superhard compact body of  claim 1 , further comprising at least one boron containing tungsten, cobalt, or tungsten-cobalt phases as detected by X-Ray diffraction (XRD). 
     
     
         8 . The sintered superhard compact body of  claim 1 , further comprising at least one phase selected from a group of WB 2 , Co 2 B, or CoW 2 B 2  as detected by X-Ray diffraction (XRD). 
     
     
         9 . The sintered superhard compact body of  claim 1 , wherein tungsten or tungsten carbide is not detected by X-Ray diffraction (XRD). 
     
     
         10 . The sintered superhard compact body of  claim 1 , wherein the tungsten and cobalt are from milling debris of milling bodies. 
     
     
         11 . A sintered superhard compact body, comprising:
 superhard particles; and   a binder phase bonding the superhard particles together, wherein the binder phase comprises tungsten and cobalt derived from milling debris, wherein the binder phase comprises stoichiometric or substoichiometric carbides, nitrides, oxides, or sums thereof from aluminum, titanium or other transition metals of group IV, V, or VI in the periodic table of elements, wherein the milling debris is from a low tungsten content milling body.   
     
     
         12 . The sintered superhard compact body of  claim 11 , wherein the milling body is a cermet milling body. 
     
     
         13 . The sintered superhard compact body of  claim 11 , wherein the superhard particles are selected from a group of cubic boron nitride, diamond, and diamond composite materials. 
     
     
         14 . The sintered superhard compact body of  claim 11 , wherein a sum of the tungsten and cobalt is in a range of from about 2 to about 10 percent by weight. 
     
     
         15 . The sintered superhard compact body of  claim 11 , wherein a ratio of tungsten to cobalt is in a range from 1.0 to 2.0. 
     
     
         16 . The sintered superhard compact body of  claim 11 , wherein a ratio of tungsten to cobalt is in a range from 1.0 to 1.8. 
     
     
         17 . The sintered superhard compact body of  claim 11 , wherein a ratio of tungsten over cobalt is in a range from 1.0 to 1.5. 
     
     
         18 . The sintered superhard compact body of  claim 11 , further comprising at least one boron containing tungsten, cobalt, or tungsten-cobalt phases as detected by X-Ray diffraction (XRD). 
     
     
         19 . A sintered superhard compact body of  claim 11 , wherein superhard particles comprise 31 wt % cBN, wherein the binder phase includes 5 wt % Al, 32 wt % Ti(C 0.6 N 0.4 ), 32 wt % substoichiometric TiN 0.72  milled using cermet bodies in an attritor mill giving an addition of 3.1+/−1 wt % W and 2.2+/−1 wt % Co from the milling bodies. 
     
     
         20 . The sintered superhard compact body of  claim 19 , further comprising at least one phase selected from a group of WB 2 , Co 2 B, or CoW 2 B 2  as detected by X-ray diffraction (XRD). 
     
     
         21 . A method of making a superhard compact, comprising:
 providing milling bodies;   milling a powder mixture of superhard powder, binder materials, and fluids with the milling bodies; and   incorporating cobalt and tungsten from the milling bodies into the superhard compact, wherein the milling bodies are low tungsten content milling bodies.   
     
     
         22 . The method of making a superhard compact of  claim 21 , further comprising preparing granules from a mixture of supperhard powder blend, organic binder materials, and fluids. 
     
     
         23 . The method of making a superhard compact of  claim 21 , further comprising pre-compacting the granules to form a soft green part of defined shape. 
     
     
         24 . The method of making a superhard compact of  claim 23 , further comprising heating the soft green part in a vacuum furnace to form a hard green part. 
     
     
         25 . The method of making a superhard compact of  claim 21 , further comprising inserting one or more the hard green parts in a container. 
     
     
         26 . The method of making a superhard compact of  claim 21 , further comprising sintering the container in a pressure cell at a predetermined pressure and temperature. 
     
     
         27 . The method of making a superhard compact of  claim 21 , further comprising removing the container from the pressure cell to reveal the superhard compact. 
     
     
         28 . The method of making a superhard compact of  claim 21 , wherein the superhard powder includes a material selected from the group of cubic boron nitride, diamond, and diamond composite materials. 
     
     
         29 . The method of making a superhard compact of  claim 21 , wherein the granules comprise a mixture of cubic boron nitride and aluminum in organic binder materials of polyethylene glycol. 
     
     
         30 . The method of making a superhard compact of  claim 21 , wherein the powder mixture contains W and Co containing compounds to accomplish a desired composition.