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 cutter for use with a drill bit includes: a substrate for mounting in a pocket of the drill bit and made from a cermet material; and a cutting table made from a polycrystalline superhard material, mounted to the substrate at an interface, having a working face opposite from the interface, and having at least four serrations formed in the working face and a side thereof. Each serration has a pair of base edges and an apical edge extending above the base edges at the side of the cutting table. Each edge extends radially or spirally from the side of the cutting table to a central portion of the working face. The edges all converge at the center of the working face.

A cutting insert for milling wellbore casing in a downhole environment includes a body having a cutting face and a chip-breaking face. The cutting face and chip-breaking face are oriented at a face angle relative to each other, the face angle being between 75 and 130. As the wellbore casing is milled, swarf is formed and work hardened. Further deformation of the swarf and movement along, or in contact with, the chip-breaking face breaks the swarf into chips that are readily flushed away or transported within the wellbore.

An earth-boring tool includes a body, blades extending longitudinally and generally radially from the body, and cutting elements located on each blade. The earth-boring tool may also include a first group of at least two adjacent blades comprising the cutting elements proximate a front cutting edge of the blades and one or more shaped inserts located rotationally following the cutting elements, and a second group of one or more additional blades comprising the cutting elements proximate the front cutting edge of the blades while being entirely free of the one or more shaped inserts. Methods include drilling a subterranean formation including engaging a formation with the cutting elements and the shaped inserts of the earth-boring tool, the shaped inserts secured at selected locations on two or more adjacent blades of the first group of blades while the second group of blades is entirely free of the shaped inserts.

A drill bit button insert is attached to a button inserts mounted in a drill bit and performs a drilling. The drill bit button insert includes a tip body and an abrasive layer that is formed of a diamond sintered body harder than the tip body and is coated at least at the button insert working surface of the tip body. The abrasive layer has two or more high hardness layers and a low hardness layer having a hardness lower than that of the high hardness layers disposed between the high hardness layers. The high hardness layers and the low hardness layer are provided from the surface side of the abrasive layer toward the tip body side.

A superhard polycrystalline construction comprises a body of polycrystalline superhard material, comprising a mass of superhard grains exhibiting inter-granular bonding and defining a plurality of interstitial regions therebetween, the superhard grains having an associated mean free path and a non-superhard phase at least partially filling a plurality of the interstitial regions and having an associated mean free path. The median of the mean free path associated with the non-superhard phase divided by (Q3Q1) for the non-superhard phase being greater than or equal to 0.50, where Q1 is the first quartile and Q3 is the third quartile; and the median of the mean free path associated with the superhard grains divided by (Q3Q1) for the superhard grains being less than 0.60. The body of polycrystalline superhard material has a first surface having a surface topology comprising one or more indentations therein and/or projections therefrom. There is also disclosed a method of forming such a construction.

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.

An earth-boring tool includes a body, blades extending longitudinally and generally radially from the body, and cutting elements located on each blade. The earth-boring tool may also include a first group of at least two adjacent blades comprising the cutting elements proximate a front cutting edge of the blades and one or more shaped inserts located rotationally following the cutting elements, and a second group of one or more additional blades comprising the cutting elements proximate the front cutting edge of the blades while being entirely free of the one or more shaped inserts. Methods include drilling a subterranean formation including engaging a formation with the cutting elements and the shaped inserts of the earth-boring tool, the shaped inserts secured at selected locations on two or more adjacent blades of the first group of blades while the second group of blades is entirely free of the shaped inserts.

A method of making a cutter structure (1) comprises placing a pre-formed body (4) of hard material having a surface topography in a canister, placing an aggregated mass of grains of superhard material (2) over said surface topography, placing a punch (10) in contact with the superhard material (2), the punch (10) having a surface with a surface topography inverse to that of the hard material body to imprint a pattern in the superhard material (2) complementary to the surface topography of the punch (10). The surface of the punch (10) contacting the superhard material (2) being formed of a ceramic material that does not react chemically with the superhard material (12) and/or a sinter catalyst for the superhard material (2). A pressure of greater than 3 GPa is then together with a temperature sufficiently high for the catalyst to melt to form the cutter structure (1) with a layer of polycrystalline superhard material bonded to the hard material and having a surface topography corresponding to the surface topography of the hard material.

A cutting element for an earth-boring tool includes a volume of superabrasive material having a cutting face and a shaped feature on the cutting face. The shaped feature may include at least one of a recess extending into the volume of superabrasive material from the cutting face and a protrusion extending outward from the cutting face. A first portion of the cutting face may have a first surface roughness, and a second portion of the cutting face may have a second surface roughness greater than the first surface roughness of the first portion of the cutting face. The volume of superabrasive material may be disposed on a substrate. Methods of forming cutting elements may include forming one or more shaped features in a cutting face of the cutting elements. Earth-boring tools may include such cutting elements.