Superhard mill cutters and related methods

Abstract

Superhard ball mill cutters and their materials and manufacturing methods.

1 . A superhard ball end mill cutter comprising: 
 a substrate,    a table of superhard material on said substrate,    a plurality of flutes cut into said superhard material, and    cutting edges along said flutes,    said cutting edges being formed of superhard material,    said cutting edges serving to cut or remove material from a workpiece.    
     
     
         2 . A cutter as recited in  claim 1  wherein said superhard material is diamond.  
     
     
         3 . A cutter as recited in  claim 1  wherein said superhard material is sintered polycrystalline diamond compact.  
     
     
         4 . A cutter as recited in  claim 1  wherein said superhard material is cubic boron nitride.  
     
     
         5 . A cutter as recited in  claim 1  wherein said superhard material is sintered polycrystalline cubic nitride compact.  
     
     
         6 . A cutter as recited in  claim 1  wherein said superhard material is selected from the group consisting of sintered polycrystalline diamond and sintered cubic boron nitride  
     
     
         7 . A cutter as recited in  claim 1  wherein said substrate and said superhard material form a sintered compact.  
     
     
         8 . A cutter as recited in  claim 1  wherein said substrate is a metal.  
     
     
         9 . A cutter as recited in  claim 1  wherein said table of said superhard material is sintered polycrystalline diamond made from at least some diamond feedstock in the size range of 0 to 70 μm.  
     
     
         10 . A cutter as recited in  claim 1  wherein said table of superhard material and said substrate are formed generally into a ball configuration.  
     
     
         11 . A cutter as recited in  claim 10  wherein said ball is bored to accept an arbor shank.  
     
     
         12 . A cutter as recited in  claim 11  further comprising an arbor shank affixed to said ball in said bore.  
     
     
         13 . A cutter as recited in  claim 1  further comprising a cutting relief adjacent said cutting edges, said cutting relief serving to enhance cutting action of the cutter.  
     
     
         14 . A cutter as recited in  claim 1  further comprising chemical bonds between said superhard material and said substrate.  
     
     
         15 . A cutter as recited in  claim 1  further comprising residual stresses which tend to retain said superhard material adjacent said substrate.  
     
     
         16 . A superhard ball end mill cutter made by the following process steps: 
 placing a quantity of superhard material crystals or powder adjacent a substrate material,    applying heat and pressure to said superhard material and said substrate material to sinter them into a compact that has a table of sintered superhard material on a substrate, and    forming flutes on said cutter.    
     
     
         17 . A superhard ball end mill cutter made by the process steps of  claim 16  wherein said flutes leave a cutting edge formed of superhard material.  
     
     
         18 . A superhard ball end mill cutter made by the process steps of  claim 16  further comprising the step of forming a cutting relief adjacent said cutting edges to enhance their cutting effect.  
     
     
         19 . A superhard ball end mill cutter cutter made by the process steps of  claim 16  wherein the cutter has a gradient transition zone between said table and said substrate  
     
     
         20 . A superhard ball end mill cutter cutter made by the process steps of  claim 16  further comprising the step of sweeping a solvent-catalyst metal from said substrate material through said superhard material in order to form bonds between said solvent-catalyst metal and said superhard material.  
     
     
         21 . A superhard ball end mill cutter as recited in  claim 16  wherein said superhard material is sintered polycrystalline diamond.  
     
     
         22 . A superhard ball end mill cutter as recited in  claim 16  wherein said superhard material is sintered polycrystalline cubic boron nitride.  
     
     
         23 . A superhard ball end mill cutter made by the process steps of  claim 16  further comprising the step of forming chemical bonds between said superhard material and said substrate.  
     
     
         24 . A superhard ball end mill cutter made by the process steps of  claim 16  further comprising the step of forming residual stresses in the cutter which tend to retain said superhard material adjacent said substrate.