A drill bit for drilling a borehole in an earthen formation has a central axis and a cutting direction of rotation. The bit includes a bit body configured to rotate about the axis in the cutting direction of rotation. The bit body includes a bit face. The bit also includes a blade extending radially along the bit face. In addition, the bit includes a first cutter element mounted to a cutter-supporting surface of the blade and a second cutter element mounted to the cutter-supporting surface of the blade. The first cutter element has a central axis and includes a first forward-facing cutting face including a first cutting tip distal the cutter supporting surface and a first planar surface extending radially from the first cutting tip toward the central axis of the first cutter element. The first planar surface is oriented at a first effective backrake angle measured between the cutter supporting surface and a surface vector of the first planar surface. The second cutter element has a central axis and comprises a second forward-facing cutting face including a second cutting tip distal the cutter supporting surface and a second planar surface extending radially from the second cutting tip toward the central axis of the second cutter element. The second planar surface is oriented at a second effective backrake angle measured between the cutter supporting surface and a surface vector of the second planar surface. The second effective backrake angle is greater than the first effective backrake angle.

Systems and methods are disclosed for a rotating superhard cutting element. The rotating cutting element includes a substrate comprising a rotating portion and a stable portion. The stable portion has a cavity and is configured to be fixed to a blade of a drill bit. The rotating cutting element further includes a retainer that rotatably secures the rotating portion of the substrate in the cavity of the stable portion of the substrate, and a cutting layer on the rotating portion of the substrate. The cutting layer has a plurality of cutting surfaces. One of the plurality of cutting surfaces has a property different from another one of the plurality of cutting surfaces. The cutting layer is configured to rotate with respect to the stable portion of the substrate and use one of the plurality of cutting surfaces based on a characteristic of a formation to be cut.

A cutter element for an earth-boring tool, comprising a polycrystalline diamond (PCD) volume joined at an interface boundary to a cemented carbide substrate. The PCD volume includes a rake face opposite the interface boundary, an edge of the rake face being suitable as a cutting edge of the cutter element. The PCD volume comprises a plurality of strata directly joined to each other at inter-strata boundaries, in which each of a first plurality of the strata comprises PCD material having a first diamond content; each of a second plurality of the strata comprises PCD material having a second diamond content; the second diamond content being greater than the first diamond content; and the strata of the first and second pluralities disposed in an alternating arrangement with respect to each other. The strata are configured and arranged such that a radial line through the edge and a centroid of the interface boundary intersects, within 1,000 microns from the edge, each of the inter-strata boundaries, and the respective tangent plane to each inter-strata boundary at the respective intersection is disposed relative to the radial line at no less than a minimum angle of 30°.

A cutting element has a cutting face with a geometry including at least one protrusion spaced a radial distance apart from an edge of the cutting element, the edge extending around an entire periphery of the cutting face, and a lower portion extending within the distance between the at least one protrusion and the edge, wherein a lower portion axial height measured between the edge and a base of the at least one protrusion is less than 30 percent of a greatest axial height of the at least one protrusion measured between the base of the at least one protrusion and an axially highest point of the at least one protrusion.

Cutting elements for earth-boring tools may include a cutting edge located proximate to a periphery of the cutting element. The cutting edge may be positioned and configured to contact an earth formation during an earth-boring operation. The cutting edge may include a first portion having a first radius of curvature and a second portion having a second, larger radius of curvature. The second portion may be circumferentially offset from the first portion.

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 polycrystalline composite tool component and associated methods are disclosed. In one example plurality of diamond particles are coated with a conforming catalyst metal coating and a plurality of graphene particles. Various asymmetric distributions of graphene particles are shown that provide a variety of material properties.

A cutting element includes a substrate configured to couple to a pocket formed in a blade of a downhole drill bit and a polycrystalline diamond portion secured to the substrate. The polycrystalline diamond portion includes a cutting face, a radial sidewall, and a cutting edge formed at a transition from the radial sidewall to the axial the cutting face. The cutting face includes a plow feature disposed at a center of the cutting face. The plow feature has a face portion and a shoulder portion. The shoulder portion extends radially outward from the face portion and axially downward toward the substrate. Additionally, the cutting face includes a recessed portion extending between the cutting edge and a radially outer edge of the shoulder portion.

Embodiments disclosed herein are directed to a superabrasive compact including one or more superabrasive cutting portions or segments, rotary drill bits including one or more superabrasive compacts, and related methods (e.g., methods of fabricating and/or operating the superabrasive compacts). For example, the superabrasive compact may include polycrystalline diamond that may form at least a portion of a working surface of the superabrasive compact.

Cutting elements for earth-boring applications may include a substrate and a polycrystalline diamond material secured to the substrate. A first region of the polycrystalline diamond material may exhibit a first volume percentage of nanoparticles bonded to diamond grains within the first region. A second region of the polycrystalline diamond material adjacent to the first region may exhibit a second, different volume percentage of nanoparticles bonded to diamond grains within the second region. Methods of making cutting elements for earth-boring applications may involve positioning a first mixture of particles having a first volume percentage of nanoparticles and a second mixture of particles having a second, different volume percentage of nanoparticles within a container. The first and second mixtures of particles may be sintered in the presence of a catalyst material to form a polycrystalline diamond material including intergranular bonds among diamond grains and nanoparticles of the polycrystalline diamond material.