A super hard polycrystalline construction comprises a body of polycrystalline super hard material, said body having an exposed working surface. The body of polycrystalline super hard material comprises a first region adjacent the working surface and a second region adjacent the first region; the first region being more thermally stable than the second region; and a plurality of apertures or channels, one or more of said apertures or channels extending from the exposed working surface of the body into the second region.

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.

Polycrystalline diamond bodies having an annular region of diamond grains and a core region of diamond grains and methods of making the same are disclosed. In one embodiment, a polycrystalline diamond body includes an annular region of inter-bonded diamond grains having a first characteristic property and a core region of inter-bonded diamond grains bonded to the annular region and having a second characteristic property that differs from the first characteristic property. The annular region decreases in thickness from a perimeter surface of the polycrystalline diamond body towards a centerline axis.

Polycrystalline compact tables for cutting elements include regions of grains of super hard material. One region of grains (first grains) and another region of grains (second grains) have different properties, such as different average grain sizes, different super hard material volume densities, or both. The region of first grains and the region of second grains adjoin one another at grain interfaces that may include a curved portion in a vertical cross-section of the table. In some embodiments, discrete regions of the first grains may be vertically disposed between discrete regions of the second grains. As such, the tables have ordered grain regions of different properties that may inhibit delamination and crack propagation through the table when used in conjunction with a cutting element. Methods of forming the tables include forming the regions and subjecting the grains to a high-pressure, high-temperature process to sinter the grains.

A cutting table comprises a polycrystalline hard material and at least one rhenium-containing structure within the polycrystalline hard material and comprising greater than or equal to about 10 weight percent rhenium. A cutting element, an earth-boring tool, and method of forming a cutting element are also described.

Methods of forming polycrystalline compacts include subjecting a plurality of grains of hard material interspersed with a catalyst material to high-temperature and high-pressure conditions to form a polycrystalline material having intergranular bonds and interstitial spaces between adjacent grains of the hard material. The catalyst material is disposed in at least some of the interstitial spaces in the polycrystalline material. The methods further comprise substantially removing the catalyst material from the interstitial spaces in at least a portion of the polycrystalline material to form an at least partially leached polycrystalline compact; and removing a portion of the polycrystalline material from which the catalyst material has been substantially removed from the at least partially leached polycrystalline compact. The polycrystalline cutting elements may be secured to a bit body of an earth-boring tool.

In one aspect of the present invention, a high impact resistant tool comprises a sintered polycrystalline diamond body bonded to a cemented metal carbide substrate at an interface, the body comprising a substantially pointed geometry with an apex, the apex comprising a curved surface that joins a leading side and a trailing side of the body at a first and second transitions respectively, an apex width between the first and second transitions is less than a third of a width of the substrate, and the body also comprises a body thickness from the apex to the interface greater than a third of the width of the substrate.

Methods of forming polycrystalline compacts include subjecting a plurality of grains of hard material interspersed with a catalyst material to high-temperature and high-pressure conditions to form a polycrystalline material having intergranular bonds and interstitial spaces between adjacent grains of the hard material. The catalyst material is disposed in at least some of the interstitial spaces in the polycrystalline material. The methods further comprise substantially removing the catalyst material from the interstitial spaces in at least a portion of the polycrystalline material to form an at least partially leached polycrystalline compact; and removing a portion of the polycrystalline material from which the catalyst material has been substantially removed from the at least partially leached polycrystalline compact. The polycrystalline cutting elements may be secured to a bit body of an earth-boring tool.

Methods of laser cutting polycrystalline diamond tables and polycrystalline diamond compacts are disclosed. Laser cutting of the polycrystalline diamond table provides an alternative to electrical-discharge machining (EDM), grinding with a diamond wheel, or lapping with a diamond wheel. Grinding or lapping with a diamond wheel is relatively slow and expensive, as diamond is used to remove a diamond material. EDM cutting of the polycrystalline diamond table is sometimes impractical or even impossible, particularly when the cobalt or other infiltrant or catalyst concentration within the polycrystalline diamond table is very low (e.g., in the case of a leached polycrystalline diamond table). As such, laser cutting provides a valuable alternative machining method that may be employed in various processes such as laser scribing, laser ablation, and laser lapping.

The strength of the bond formed by a braze material between a polycrystalline hard material and a hard composite may be physically strengthened. For example, a method of physical strengthening may include etching a bonding surface of a polycrystalline material body to produce a synthetic topography on the bonding surface of the polycrystalline material body, the bonding surface opposing a contact surface of the polycrystalline material body; and brazing the bonding surface of the polycrystalline material body having the synthetic topography to a bonding surface of a hard composite using a braze material.