Polycrystalline diamond cutters having modified residual stresses
AssigneeBaker Hughes Incorporated
InventorsTrent N. Butcher, Ralph M. Horton, Stephen R. Jurewicz, Danny E. Scott, Redd H. Smith
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Abstract
The residual stresses that are experienced in polycrystalline diamond cutters, which lead to cutter failure, can be effectively modified by selectively thinning the carbide substrate subsequent to high temperature, high pressure (sinter) processing, by selectively varying the material constituents of the cutter substrate, by subjecting the PDC cutter to an annealing process during sintering, by subjecting the formed PDC cutter to a post-process stress relief anneal, or a combination of those means.
Claims26
An improved polycrystalline diamond compact cutter including a carbide substrate secured to a polycrystalline diamond table, the carbide substrate comprised of at least one binder constituent and at least one carbide constituent, the polycrystalline diamond compact cutter comprising
- a carbide substrate modified to exhibit at least a reduced level of residual tensile stress, as compared to a carbide substrate of a conventional polycrystalline diamond compact cutter in an immediately post-fabricated state, formed by performance with respect thereto of at least one of the acts of:
- having selectively limited an initial thickness of the carbide substrate of the improved cutter, having selectively reduced an initial thickness of the carbide substrate to a final thickness, having selectively varied at least one of the at least one carbide constituent and the at least one binder constituent of the carbide substrate of the improved cutter, having subjected the polycrystalline diamond compact cutter to an annealing process while securing the polycrystalline diamond table to the carbide substrate, and having subjected the polycrystalline diamond compact cutter to an annealing process after having secured the polycrystalline diamond table to the carbide substrate.
An improved polycrystalline diamond compact cutter including a carbide substrate bonded to a polycrystalline diamond table, the improved polycrystalline diamond compact cutter comprising:
- at least one constituent added to the carbide substrate inducing a reduction of a state of residual tensile stress in the carbide substrate and inducing an enhancement in a state of residual compressive stress in the polycrystalline diamond table of the improved polycrystalline diamond compact cutter as compared to a state of residual compressive stress in a polycrystalline diamond table and a state of residual stress in a carbide substrate of a post-fabricated, conventional polycrystalline diamond compact cutter.
Dependencies are inferred from the claim text.