A cutting tool is a cutting tool comprising a substrate and a coating film disposed on the substrate, in which the coating film includes a first layer, the first layer is composed of an alternate layer where a first unit layer and a second unit layer are alternately stacked, the first unit layer is composed of Ti.sub.1-a-bAl.sub.aCe.sub.bN, a is between greater than or equal to 0.350 and equal to or less than 0.650, b is between greater than or equal to 0.001 and equal to or less than 0.100, the second unit layer is composed of Ti.sub.cSi.sub.1-cN, and c is between greater than or equal to 0.20 and equal to or less than 0.99.

A drill bit for cutting formation comprises a bit body, a plurality of cutters, and a plurality of blades with pockets to accommodate the cutters, respectively. Each of the plurality of cutters has a substrate, an ultra-hard layer, an inclined surface on the top of the ultra-hard layer, wherein the inclined surface slants downward from a cutting edge to a trailing edge. The cutter can improve cutting efficiency and service life.

Polycrystalline diamond may include a working surface and a peripheral surface extending around an outer periphery of the working surface. The polycrystalline diamond includes a first volume including an interstitial material and a second volume having a leached region that includes boron and titanium. A method of fabricating a polycrystalline diamond element may include positioning a first volume of diamond particles adjacent to a substrate, the first volume of diamond particles including a material that includes a group 13 element, and positioning a second volume of diamond particles adjacent to the first volume of diamond particles such that the first volume of diamond particles is disposed between the second volume of diamond particles and the substrate, the second volume of diamond particles having a lower concentration of material including the group 13 element than the first volume of diamond particles.

A cutting element includes a body, a non-planar cutting face formed on a first end of the body, and an edge formed around a perimeter of the cutting face. The cutting face includes a central raised portion, and the edge has an edge angle defined between the cutting face and a side surface of the body. The edge angle varies around the perimeter of the cutting face and includes an acute edge angle defined by a portion of the cutting face extending downwardly from the edge to a depth from the cutting angle. The portion of the edge defining the acute edge angle may be directly adjacent: a side surface of the cutting element; a bevel of the cutting element; or a flat region at the perimeter of the cutting element or bevel.

A super hard polycrystalline construction is disclosed as comprising a body of super hard material bonded to a substrate. The body of super hard material comprises an outer peripheral region formed of interbonded grains of super hard material extending peripherally around one or more inner regions, the outer peripheral region having a radial thickness proportional to the square of the ratio of the fracture toughness of the material forming said outer peripheral region to the transverse rupture strength of the material forming said outer peripheral region (I) where TRS is the transverse rupture strength and K.sub.IC is the fracture toughness.

A cutting element for a drill bit includes a PCD cutting face having a ridge that extends away from the periphery towards the center of the cutting face, terminating in a curved, central most ridge end. The cutting face further includes a surrounding surface consisting of the entire cutting face except for the ridge. The surrounding surface is free of flats and includes two side regions and a ramp region therebetween. The surrounding surface is continuously curved along a curved path that extends from the first side region to the ramp region to the other side region. In profile views, the surrounding surface may be linear moving from the top surface of the ridge to the periphery at every location along the curved path.

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 tools may include a polycrystalline, superabrasive material secured to an end of a substrate. The polycrystalline superabrasive material may include a first transition surface and a second transition surface. A waveform may extend around a circumference of the second transition surface, a surface of the waveform tapered toward from the substrate and extending radially from the second transition surface toward the central axis. The surface of the waveform may extend from the second transition surface to a planar surface of the polycrystalline located at a same distance from the substrate as troughs of the waveform surface, the planar surface oriented perpendicular, and located proximate, to the central axis.

Cutting elements for use with earth-boring tools include a cutting table having at least two sections where a boundary between the at least two sections is at least partially defined by a discontinuity formed in the cutting table. Earth-boring tools including a tool body and a plurality of cutting elements carried by the tool body. The cutting elements include a cutting table secured to a substrate. The cutting table includes a plurality of adjacent sections, each having a discrete cutting edge where at least one section is configured to be selectively detached from the substrate in order to substantially expose a cutting edge of an adjacent section. Methods for fabricating cutting elements for use with an earth-boring tool including forming a cutting table comprising a plurality of adjacent sections.

Cutting elements for earth-boring tools may include a substrate and a polycrystalline, superabrasive material secured to an end of the substrate. The polycrystalline superabrasive material may include a first transition surface extending in a direction oblique to a central axis of the substrate, a second transition surface extending in a second direction oblique to the central axis, the second direction being different from the first direction, and a curved, stress-reduction feature located on the second transition surface.