| abstract |
A method for fabricating a drill bit comprising a plurality of composite compact cutters by furnace brazing each cutter in a recess in the crown of the drill bit. In one embodiment, each cutter is comprised of a mass of bonded polycrystalline abrasive, a substrate bonded to said abrasive mass and a thin layer of brazing filler metal coating the exposed surface of the substrate. In another embodiment, the cutter comprises a composite compact cutter blank bonded to one end of a cemented carbide pin, and a thin layer of brazing filler material coating the substrate of the blank and the carbide pin. In both embodiments, the coating of brazing filler metal is applied to the cutters by dipping in a molten bath of the filler metal. |