REDISTRIBUTION OF BINDER IN A CEMENTED CARBIDE DRILL BIT INSERT Russian patent published in 2023 - IPC C22C29/08 B22F3/24 B22F5/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to a method for redistributing a binder in a cemented carbide insert for a drill bit, to a cemented carbide insert for a drill bit with a hardness gradient. A method for manufacturing a cemented carbide insert for a drill bit containing a WC-based hard phase component, if necessary, one or more additional solid phase components and a binder, includes the steps of: a) providing a raw cemented carbide insert for a drill bit, b) applying at least one extractor of a binder selected from a metal oxide or a metal carbonate onto the surface of said raw insert; and c) sintering the raw insert. A binder extractor, selected from a metal oxide or a metal carbonate, is applied as a liquid dispersion or slurry to a local area of the surface of the untreated cemented carbide insert in the upper part of the drill bit. After sintering the insert, it is subjected to a tumbling process in a centrifugal tumbling device for strain hardening under the following conditions: ΔHV3%≥ 9.72-0.00543×HV3_bulk,Δ HV3%=100×(HV_0.3mm-HV_bulk)/ HV _bulk, where ΔHV3 characterizes the change in Vickers hardness at a load of 3 kg after tumbling in %, HV3_bulk - Vickers hardness data at a load of 3 kg for at least 30 indentation points, measured in the central part of the cemented carbide insert for a drill bit, HV_bulk - Vickers hardness data for at least 30 indentation points, measured at the centre of the cemented carbide insert for drill bits, HV_0.3mm - Vickers hardness data for at least 30 indentation points, measured at a depth of 0.3mm below the surface after tumbling of the cemented carbide drill bit insert.

EFFECT: high wear resistance of the cemented carbide drill bit insert.

13 cl, 26 dwg, 5 tbl, 6 ex