SELECTIVELY LEACHED, POLYCRYSTALLINE STRUCTURES FOR CUTTING ELEMENTS OF DRILL BITS

• Main Authors: CLEGG, JOHN MARTIN, MURDOCK, ANDREW DAVID, DUBOSE, WILLIAM HENRY, BOWDEN, NEAL ALAN, MUMMA, MATTHEW DOUGLAS
• Format: Patent
• Language: English; French; German
• Published: 15.07.2015
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; ARTIFICIAL STONE; CEMENTS; CERAMICS; CHEMISTRY; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; CONCRETE; CRYSTAL GROWTH; EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; GRINDING; LIME, MAGNESIA; METALLURGY; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS; PERFORMING OPERATIONS; POLISHING; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; REFRACTORIES; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; SLAG; TOOLS FOR GRINDING, BUFFING, OR SHARPENING; TRANSPORTING; TREATMENT OF NATURAL STONE; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

The rate of leaching of a polycrystalline diamond (PCD) cutting layer for cutting elements or other wear parts is varied by introduction into the PCD of an additive prior to leaching. Selective introduction of the additive into one or more regions of a PCD cutting structure allows controlling leaching rates of selective leaching of parts of the PCD structure, which allows for creating of a boundary between the leached and non-leached regions of a PCD structure to be made so that is not parallel to the surface or surfaces exposed to the leaching solution. The additive is comprised of a material that increases the permeability of the PCD or acceptance of the PCD to the leaching solution, such as a hydrophile.