Cubic boron nitride flat cutting element compacts

Abstract

Flat composite cutting elements are provided having a layer of Cubic Boron Nitride comprising less than 80 volume percent Cubic Boron Nitride sandwiched between two layers each made from a material brazeable to carbide or steel.

1 . A cutting tool composite compact blade comprising: 
 a first layer formed from a material selected from the group consisting of refractory metals and carbides of refractory metals selected from the groups IVB, VB and VIB of the periodic table;    a second layer formed from a material selected from the group consisting of refractory metals and carbides of refractory metals selected from the groups IVB, VB and VIB of the periodic table; and    a third layer of ultra hard between the first and second layers, wherein said third layer comprises less than 80% by volume CBN.    
     
     
         2 . A composite compact blade as recited in    claim 1    wherein the first layer is formed from a refractory metal and wherein the second layer is formed from a material selected from the group consisting of carbides of refractory metals selected from the groups IVB, VB and VIB of the periodic table.  
     
     
         3 . A composite compact blade as recited in    claim 1    wherein the first layer is formed from a material selected from the group consisting of carbides of refractory metals selected from the groups IVB, VB and VIB of the periodic table and wherein the second layer is formed from a material selected from the group consisting of carbides of refractory metals selected from the groups IVB, VS and VIB of the periodic table.  
     
     
         4 . A composite compact blade as recited in    claim 1    wherein the first layer is formed from a refractory metal and wherein the second layer is formed from a refractory metal.  
     
     
         5 . A composite compact blade as recited in    claim 1    wherein each of the first and second layer comprises a binder phase in the range of 5% to 20% by volume.  
     
     
         6 . A composite compact blade as recited in    claim 1    wherein the third layer comprises less than 40% by volume CBN.  
     
     
         7 . A composite compact blade as recited in    claim 1    wherein the third layer further comprises a material selected from the group of AlN, AlB 2  and Tungsten Carbide in the range of about 10% to 15% by volume.  
     
     
         8 . A composite compact blade as recited in    claim 1    wherein the third layer further comprises a second phase material in the range of about 0 to 45% by volume.  
     
     
         9 . A composite compact blade as recited in    claim 8    wherein the second phase material comprises a material selected from group consisting of TiN, TiC, and TiCN.  
     
     
         10 . A composite compact blade as recited in    claim 8    wherein the second phase material comprises a C:N ratio not greater than 1.  
     
     
         11 . A composite compact blade as recited in    claim 1    wherein the first layer comprises a thickness and wherein the third layer comprises a thickness and wherein the ratio of the thickness of the first layer to the thickness of the third layer is in the range of about 9:1 to about 36:1.  
     
     
         12 . A composite compact blade as recited in    claim 1    wherein the third layer comprises a non-uniform face, facing toward the first layer.  
     
     
         13 . A composite compact blade as recited in    claim 1    wherein the first layer comprises a non-uniform face facing toward the third layer.  
     
     
         14 . A composite compact blade as recited in    claim 1    wherein the first and second layers each comprise a non-planar face, wherein the non-planar face of the first layer faces toward the non-planar face of the second layer.  
     
     
         15 . A composite compact blade as recited in    claim 1    wherein the third layer comprises a first non-planar face facing toward the first layer and a second non-planar face opposite the first non-planar face facing toward the second layer.  
     
     
         16 . A method for making a composite compact blade comprising a CBN layer sandwiched between a refractory metal layer and a carbide layer, the method comprising the steps of: 
 providing a can made from a refractory metal the can having an open end and a cover;    placing a layer of CBN in the can;    covering the can open end with the cover forming an assembly; and    sintering the assembly for forming the cutting element having a CBN layer and another layer formed by a portion of the can.    
     
     
         17 . A method as recited in    claim 15    further comprising the step of cutting the sintered assembly to remove portions of the sintered can.  
     
     
         18 . A method as recited in    claim 15    wherein another portion of the can forms another layer of refractory metal, wherein the two refractory metal layers sandwich the CBN layer.  
     
     
         19 . A method as recited in    claim 15    further comprising the step of providing a layer of a carbide material between the can and the CBN layer, the carbide material selected from the group consisting of carbides of a refractory metals selected from the groups IVB, VB and VIB of the periodic table.  
     
     
         20 . A method as recited in    claim 15    wherein the refractory metal can comprises a material selected from the group consisting of refractory metals selected from the groups IVB, VB and VIB of the periodic table.