A method of forming a cutting element for an earth-boring tool may include directing at least one energy beam at a surface of a volume of polycrystalline superabrasive material including interstitial material disposed in regions between inter-bonded grains of polycrystalline superabrasive material. The method includes ablating the interstitial material with the at least one energy beam such that at least a portion of the interstitial material is removed from a first region of the volume of polycrystalline superabrasive material without any substantial degradation of the inter-bonded grains of superabrasive material or of bonds thereof in the first region.

A method of forming a cutting element for an earth-boring tool may include directing at least one energy beam at a surface of a volume of polycrystalline superabrasive material including interstitial material disposed in regions between inter-bonded grains of polycrystalline superabrasive material. The method includes ablating the interstitial material with the at least one energy beam such that at least a portion of the interstitial material is removed from a first region of the volume of polycrystalline superabrasive material without any substantial degradation of the inter-bonded grains of superabrasive material or of bonds thereof in the first region.

Methods for forming a polycrystalline diamond compact (PDC) drill bit from catalyst-free synthesized polycrystalline diamonds are described. The polycrystalline diamonds are deposited within a mold. In some cases, a matrix body material is deposited within the mold, and an infiltration process is performed to bond the polycrystalline diamonds to the matrix body material to form the PDC drill bit. In some cases, a drill bit body is formed within the mold, and forming the drill bit body within the mold includes depositing a layer of matrix body material particles within the mold, depositing an adhesive ink within the mold, and curing the adhesive ink. In some cases, a sintering process is performed after forming the drill bit body to remove at least a portion of the adhesive ink and increase a density of the drill bit body to form the PDC drill bit.

Cutters for a downhole drill bit can be formed by providing a catalyst-free synthesized polycrystalline diamond (PCD) having a cross-sectional dimension of at least 8 millimeters; providing a substrate comprising tungsten carbide; and attaching the synthesized PCD to the substrate comprising tungsten carbide to form a PDC cutter.

Embodiments of the invention relate generally to overmolded protective leaching masks, and methods of manufacturing and using the same for leaching superabrasive elements such as polycrystalline diamond elements. In an embodiment, a protective leaching mask assembly includes a superabrasive element including a central axis and a superabrasive table, and a protective mask overmolded onto at least a portion of the superabrasive element. The protective mask includes a base portion and at least one sidewall extending from the base portion and defining an opening generally opposite the base portion. The at least one sidewall includes an inner surface configured to abut with a selected portion of the superabrasive element being chemically resistant to a leaching agent and an outer surface sloping at an oblique angle relative to the central axis.

A superhard polycrystalline construction comprises a body of polycrystalline superhard material comprising a superhard phase, and a non-superhard phase dispersed in the superhard phase, the superhard phase comprising a plurality of inter-bonded superhard grains. The non-superhard phase comprises particles or grains that do not chemically react with the superhard grains and form less than around 10 volume % of the body of polycrystalline superhard material. There is also disclosed a method of forming such a superhard polycrystalline construction.

A superhard polycrystalline construction comprises a body of polycrystalline superhard material comprising a superhard phase, and a non-superhard phase dispersed in the superhard phase, the superhard phase comprising a plurality of inter-bonded superhard grains. The non-superhard phase comprises particles or grains that do not chemically react with the superhard grains and form less than around 10 volume % of the body of polycrystalline superhard material. There is also disclosed a method of forming such a superhard polycrystalline construction.

A cutter element for a drill bit includes a base portion having a central axis, a first end, and a second end. In addition, the cutter element includes a cutting layer fixably mounted to the first end of the base portion. The cutting layer includes a cutting face distal the base portion. The cutting face includes a first planar surface and a second planar surface that is circumferentially-spaced from the first planar surface. Each planar surface is positioned at an outer periphery of the cutting face adjacent the radially outer surface of the cutting layer. The cutting face also includes a saddle surface including a crown and a pair of lateral side surfaces that slope down and away from the crown toward the radially outer cylindrical surface of the cutting layer. The crown extends from the first planar surface to the second planar surface.

A cutting element for use on a drill bit is disclosed. The cutting element includes a polycrystalline diamond table having a multi-tiered surface. The polycrystalline diamond table has at least a first cutting surface and a second cutting surface. The polycrystalline diamond table has a step between the first and second cutting surfaces. The step is transitional surface feature between the first and second cutting surfaces, which are positioned at different elevations in the polycrystalline diamond table.

A drill bit includes a bit body providing one or more blades and defining a cone section extending from a centerline of the bit body a first distance, a nose section extending from the cone section a second distance, a shoulder section extending from the nose section a third distance, and a gauge section extending from the shoulder section a fourth distance. The drill but further includes one or more cutting elements mounted to the one or more blades outside of the cone section such that the cone section is void of cutting elements, and a plurality of milling elements secured to the bit body within the cone section.