Selectively leached, polycrystalline structures for cutting elements of drill bits

• Main Authors: Murdock, Andrew David, Bowden, Neal Alan, DuBose, William Henry, Mumma, Matthew Douglas, Clegg, John Martin
• Format: Patent
• Language: English
• Published: 25.12.2018
• Subjects: ARTIFICIAL STONE; CEMENTS; CERAMICS; CHEMISTRY; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; CONCRETE; 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; REFRACTORIES; SLAG; TOOLS FOR GRINDING, BUFFING, OR SHARPENING; TRANSPORTING; TREATMENT OF NATURAL STONE

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.