A polycrystalline super hard construction is disclosed having a first region comprising a body of thermally stable polycrystalline super hard material having an exposed surface forming a working surface, and a peripheral side edge, the polycrystalline super hard material comprising a plurality of grains of super hard material; a second region forming a substrate to the first region; and a third region interposed between the first and second regions. The third region extends across a surface of the second region along an interface, the interface comprising a portion having an uneven topology and a substantially planar portion, the third region comprising a composite material including a first phase comprising a plurality of non-intergrown diamond grains, and a matrix material.

The invention discloses a drill bit design method based on rock crushing principle with local variable strength, including: drill bit is divided into local crushing feature regions; strength mode factors of the local crushing feature regions are calculated; a difference among strength mode factors of the local crushing feature regions is obtained to obtain a vector sum of horizontal cutting forces of the drill bit tooth corresponding to the same group of cutting tooth on the drill bit; treating the difference among the strength mode factors of the local crushing feature region as a target control condition for drill bit design. Based on the rock crushing principle with local variable strength, after dividing the symmetrical cutting tooth into groups, the strength variation factors of the symmetrical position are adjusted and balanced, so that the rock crushing strength of different local crushing feature regions can be changed in a targeted manner.

The invention discloses a drill bit design method based on rock crushing principle with local variable strength, including: drill bit is divided into local crushing feature regions; strength mode factors of the local crushing feature regions are calculated; a difference among strength mode factors of the local crushing feature regions is obtained to obtain a vector sum of horizontal cutting forces of the drill bit tooth corresponding to the same group of cutting tooth on the drill bit; treating the difference among the strength mode factors of the local crushing feature region as a target control condition for drill bit design. Based on the rock crushing principle with local variable strength, after dividing the symmetrical cutting tooth into groups, the strength variation factors of the symmetrical position are adjusted and balanced, so that the rock crushing strength of different local crushing feature regions can be changed in a targeted manner.

A drill bit for cutting formation comprises a bit body, a plurality of cutters, a plurality of blades with pockets to accommodate the cutters respectively. Each of the plurality of cutters has an ultra-hard layer, two side facets extending obliquely inward from the substrate to a top surface of the ultra-hard layer, a convex portion between the two side facets. The convex portion comprises a transition surface and the transitional surface is convex as it extends between adjacent the two side facets. The curvature of the transitional surface varies along the cutter axis with the curvature at the cutting edge larger than the curvature of the cutter circumferential surface.

A superabrasive element includes a substrate and a superabrasive table bonded to the substrate, the superabrasive table including a polished surface having a polished finish, the polished surface extending over at least a central, apical region of the superabrasive table, and an unpolished surface including an unpolished finish, the unpolished surface surrounding a majority of the polished surface. A method of manufacturing a superabrasive element includes providing a superabrasive element having a substrate and a superabrasive table bonded to the substrate and polishing at least a central, apical region of the superabrasive table to form a polished surface, without polishing an unpolished surface of the superabrasive table, the unpolished surface surrounding a majority of the polished surface.

A polycrystalline super hard construction comprises a body of polycrystalline super hard material and a substrate bonded to the body along an interface. The substrate a first end surface forming the interface, the first end surface comprising a projection extending from the body of the substrate into the body of super hard material towards the cutting face, the body of polycrystalline material extending around the projection. The body of polycrystalline material comprises a first region more thermally stable than a second region, the first region comprising an annular portion located around the projection, the second region extending between and bonding the first region to the substrate. The first region has a thickness from the cutting face along the peripheral side edge to the interface of at least around 3 mm and a portion of the projection has a thickness measured in a plane extending along the longitudinal axis of at least around 3 mm.

A polycrystalline super hard construction comprises a body of polycrystalline super hard material and a substrate bonded to the body along an interface. The substrate a first end surface forming the interface, the first end surface comprising a projection extending from the body of the substrate into the body of super hard material towards the cutting face, the body of polycrystalline material extending around the projection. The body of polycrystalline material comprises a first region more thermally stable than a second region, the first region comprising an annular portion located around the projection, the second region extending between and bonding the first region to the substrate. The first region has a thickness from the cutting face along the peripheral side edge to the interface of at least around 3 mm and a portion of the projection has a thickness measured in a plane extending along the longitudinal axis of at least around 3 mm.

A cutting device for use in a drill bit has a body including an ultrahard material. The body has a top surface, a front surface, and at least one lateral surface adjacent the top surface. The lateral surface is oriented at a surface angle relative to the top surface between 30 and 150 degrees. One or more locking features are located on the lateral surface.

A drilling tip includes a tip main body that has a posterior end portion having a columnar or disk shape centered on a tip center line and a distal end portion and is made of a cemented carbide and a hard layer that coats the distal end portion and is made of a polycrystalline diamond sintered body. The distal end portion has a convex portion, and a concave portion. A diameter D of the posterior end portion is 8 mm to 20 mm. A ratio r1/D of a radius r1 of the convex portion is 0.1 to 0.65, and a ratio r2/D of a radius r2 of the concave portion is 0.05 to 3.0. An angle formed by a straight line that connects a tangent point which the convex portion tangents to the concave portion and a center of the convex portion to each other is 20° to 90°.

A drilling tip includes a tip main body that has a posterior end portion having a columnar or disk shape centered on a tip center line and a distal end portion and is made of a cemented carbide and a hard layer that coats the distal end portion and is made of a polycrystalline diamond sintered body. The distal end portion has a convex portion, and a concave portion. A diameter D of the posterior end portion is 8 mm to 20 mm. A ratio r1/D of a radius r1 of the convex portion is 0.1 to 0.65, and a ratio r2/D of a radius r2 of the concave portion is 0.05 to 3.0. An angle formed by a straight line that connects a tangent point which the convex portion tangents to the concave portion and a center of the convex portion to each other is 20° to 90°.