Cutting elements for rotary drill bits
AssigneeCamco International (UK) Limited
InventorsNigel Dennis Griffin, Terry R. Matthias
Life of this patent
Estimating the term…
Abstract
A preform cutting element, for a rotary drill bit, and a rotary drill bit with prefrom cutting elements including a facing table of superhard material having a front face, a rear surface is bonded to the front surface of a substrate which is less hard than the superhard material and has a rim or edge section of the superhard material at least partially covered by a metallic material different from the substrate material. The metallic material is bonded to the edge section of the superhard material through a high pressure bonding step. The superhard material covered by the compliant metallic material is protected from impact forces occurring in drill bit operations such as tripping.
Claims23
A preform cutting element, comprising a facing table of superhard material having a front face and a rear surface bonded to a front surface of a substrate which is less hard than the superhard material, the facing table having edges between the front face and the rear surface, the edges being at least partially covered with a layer made of a metallic material less hard than the superhard material but different from the substrate material, and the layer being high pressure bonded to the edges of the facing table.
A rotary drill bit comprising a bit body and a plurality of preform cutting elements, said elements each having a facing table of superhard material having a front face and a rear surface bonded to a front surface of a substrate which is less hard than the superhard material, the facing table having edges between the front face and the rear surface, the edges being at least partially covered with a layer made of material less hard than the superhard material but different from the substrate material, and the layer being sintered to the edges wherein the layer material is softer than the substrate material.
A rotary drill bit comprising a bit body and a plurality of preform cutting elements, said elements each having a facing table of superhard material having a front face and a rear surface bonded to a front surface of a substrate which is less hard than the superhard material, the facing table having edges between the front face and the rear surface, the edges being at least partially covered with a layer made of material less hard than the superhard material but different from the substrate material, and the layer being sintered to the edges wherein the layer is an alloy of a material selected from a group consisting of molybdenum (Mo), tantalum (Ta), niobium (Nb), and titanium (Ti).
A rotary drill bit comprising a bit body and a plurality of preform cutting elements, said elements each having a facing table of superhard material having a front face and a rear surface bonded to a front surface of a substrate which is less hard than the superhard material, the facing table having edges between the front face and the rear surface, the edges being at least partially covered with a layer made of material less hard than the superhard material but different from the substrate material, and the layer being sintered to the edges wherein the layer material is a residual of a metallic enclosure enclosing the superhard material and the substrate material during the high pressure bonding, the residual not being removed prior to insertion of the cutting element into a body of a drill bit.
Dependencies are inferred from the claim text.