Abstract: Hardfacing materials include particles of polycrystalline diamond (PCD) material embedded within a matrix material. The PCD particles comprise a plurality of inter-bonded diamond grains. Material compositions and structures used to apply a hardfacing material to an earth-boring tool (e.g., welding rods) include PCD particles. Earth-boring tools include a hardfacing material comprising PCD particles embedded within a matrix material on at least a portion of a surface of a body of the tools. Methods of forming a hardfacing material include subjecting diamond grains to elevated temperatures and pressures to form diamond-to-diamond bonds between the diamond grains and form a PCD material. The PCD material is broken down to form PCD particles that include a plurality of inter-bonded diamond grains. Methods of hardfacing tools include bonding PCD particles to surfaces of the tools using a metal matrix material.

Abstract: Methods of forming cutting element pockets in blades of earth-boring tools include forming a first recess and a second recess intersecting at a location defining the a back of the pocket using a cutter oriented in a manner so as to avoid tool path interference with adjacent blades. A filler material is disposed in the second recess to the location of the back of the pocket. Earth-boring tools including such cutting element pockets.

Abstract: A cutting element for use in a drill bit for drilling subterranean formations including a substrate having a body including an upper surface extending transversely to a longitudinal axis of the body, a superabrasive layer overlying the upper surface of the substrate, wherein the superabrasive layer includes an annular shape having a central opening defined by an inner surface. The cutting element further includes an abrasive insert overlying the upper surface of the substrate and disposed within the central opening of the superabrasive layer, wherein the abrasive insert has an upper surface having a surface roughness (Ra) of greater than about 1 micron.

Abstract: Methods of forming earth-boring rotary drill bits include providing a bit body, providing a shank that is configured for attachment to a drill string, and attaching the shank to the bit body. Providing a bit body includes providing a green powder component having a first region having a first composition and a second region having a second, different composition, and at least partially sintering the green powder component. Other methods include providing a powder mixture, pressing the powder mixture to form a green component, and sintering the green component to a final density. A shank is provided that includes an aperture, and a feature is machined in a surface of the bit body. The aperture is aligned with the feature, and a retaining member is inserted through the aperture. An earth-boring bit includes a bit body comprising a particle-matrix composite material including a plurality of hard particles dispersed throughout a matrix material. A shank is attached to the bit body using a retaining member.

Abstract: Methods of forming bit bodies for earth-boring bits include assembling green components, brown components, or fully sintered components, and sintering the assembled components. Other methods include isostatically pressing a powder to form a green body substantially composed of a particle-matrix composite material, and sintering the green body to provide a bit body having a desired final density. Methods of forming earth-boring bits include providing a bit body substantially formed of a particle-matrix composite material and attaching a shank to the body. The body is provided by pressing a powder to form a green body and sintering the green body. Earth-boring bits include a unitary structure substantially formed of a particle-matrix composite material. The unitary structure includes a first region configured to carry cutters and a second region that includes a threaded pin. Earth-boring bits include a shank attached directly to a body substantially formed of a particle-matrix composite material.

Abstract: A cutting element for use in drilling subterranean formations. The cutting element includes a superabrasive table mounted to a supporting substrate. The superabrasive table includes a two-dimensional cutting face having a cutting edge along at least a portion of its periphery, and a surface comprising a chamfer extending forwardly and inwardly from proximate a peripheral cutting edge at a first acute angle of orientation of greater than about 45° with respect to the longitudinal axis of the cutting element, and to no greater than a selected depth. The chamfer may be arcuate or planar, and of a dimension sufficient to ensure that a wear flat generated during use of the cutting element remains outside the inner boundary of the chamfer within the chamfer envelope, and small enough to maintain aggressive cutting characteristics for the cutter. Drill bits and drilling tools bearing the cutting elements are also disclosed.

Abstract: Methods of forming earth-boring rotary drill bits include providing a bit body, providing a shank that is configured for attachment to a drill string, and attaching the shank to the bit body. Providing a bit body includes providing a green powder component having a first region having a first composition and a second region having a second, different composition, and at least partially sintering the green powder component. Other methods include providing a powder mixture, pressing the powder mixture to form a green component, and sintering the green component to a final density. A shank is provided that includes an aperture, and a feature is machined in a surface of the bit body. The aperture is aligned with the feature, and a retaining member is inserted through the aperture. An earth-boring bit includes a bit body comprising a particle-matrix composite material including a plurality of hard particles dispersed throughout a matrix material. A shank is attached to the bit body using a retaining member.

Abstract: Methods of forming bit bodies for earth-boring bits include assembling green components, brown components, or fully sintered components, and sintering the assembled components. Other methods include isostatically pressing a powder to form a green body substantially composed of a particle-matrix composite material, and sintering the green body to provide a bit body having a desired final density. Methods of forming earth-boring bits include providing a bit body substantially formed of a particle-matrix composite material and attaching a shank to the body. The body is provided by pressing a powder to form a green body and sintering the green body. Earth-boring bits include a unitary structure substantially formed of a particle-matrix composite material. The unitary structure includes a first region configured to carry cutters and a second region that includes a threaded pin. Earth-boring bits include a shank attached directly to a body substantially formed of a particle-matrix composite material.

Abstract: Earth-boring tools comprise a shank comprising a distal connector including a set of threads thereon and a bit body comprising a shank connector, also comprising at least one set of threads thereon. The set of threads on the distal connector and the at least one set of threads on the shank connector are at least substantially bound together. Methods of forming such earth-boring tools are also disclosed, as well as methods of securing a bit body of an earth-boring tool to a shank.

Abstract: A method for conducting nondestructive internal inspection of a rotary drill bit used for drilling subterranean formations comprises communicating ultrasonic waves into a drill bit and detecting ultrasonic waves that are reflected by at least a portion of the drill bit. In some embodiments, the waves may be directed into the drill bit from within a longitudinal bore thereof. Reflected waves also may be detected from within the bore. The methods may be used to develop threshold acceptance criteria for classifying drill bits as acceptable or unacceptable to prevent catastrophic failures of drill bits during use. Systems and apparatuses are disclosed for conducting nondestructive ultrasonic inspection of a drill bit used for drilling subterranean formations. The systems and apparatuses may comprise an ultrasonic probe configured for insertion within an internal longitudinal bore of a drill bit. Drill bits are disclosed that are configured to facilitate nondestructive ultrasonic inspection thereof.

Abstract: A first green or brown object is sintered while being supported by a second green or brown object in a furnace, and a body of an earth-boring tool is formed from the first object. An object is sectioned to form first and second structures, and the first structure is sintered within a furnace while it is supported by (e.g., resting on) the second structure. A layer of powder material is provided on a green or brown object, another green or brown object is rested on the powder material over the first green or brown object, and the first and second green or brown objects are sintered with the powder material therebetween. Intermediate structures formed during fabrication of a body of an earth-boring tool include a layer of powder between a green or brown tool body precursor and a green or brown structure supporting the green or brown tool body.

Abstract: Methods of forming cutter assemblies for use on earth-boring tools include sintering a cone structure to fuse one or more cutting elements thereto and having a hardened land area. In some embodiments, one or more green, brown, or fully sintered cutting elements may be positioned on a green or brown cone structure prior to sintering the cone structure to a final density. Cutter assemblies may be formed by such methods, and such cutter assemblies may be used in earth-boring tools such as, for example, earth-boring rotary drill bits and hole openers.

Abstract: A method for conducting nondestructive internal inspection of a rotary drill bit used for drilling subterranean formations comprises communicating ultrasonic waves into a drill bit and detecting ultrasonic waves that are reflected by at least a portion of the drill bit. In some embodiments, the waves may be directed into the drill bit from within a longitudinal bore thereof. Reflected waves also may be detected from within the bore. The methods may be used to develop threshold acceptance criteria for classifying drill bits as acceptable or unacceptable to prevent catastrophic failures of drill bits during use. Systems and apparatuses are disclosed for conducting nondestructive ultrasonic inspection of a drill bit used for drilling subterranean formations. The systems and apparatuses may comprise an ultrasonic probe configured for insertion within an internal longitudinal bore of a drill bit. Drill bits are disclosed that are configured to facilitate nondestructive ultrasonic inspection thereof.

Abstract: Methods of forming earth-boring rotary drill bits by forming and joining two less than fully sintered components, by forming and joining a first fully sintered component with a first shrink rate and forming a second less than fully sintered component with a second sinter-shrink rate greater that that of the first shrink rate of the first fully sintered component, by forming and joining a first less than fully sintered component with a first sinter-shrink rate and by forming and joining at least a second less than fully sintered component with a second sinter-shrink rate less than the first sinter-shrink rate.

Abstract: Geometric compensation techniques are used to improve the accuracy by which features may be located on drill bits formed using particle compaction and sintering processes. In some embodiments, a positional error to be exhibited by at least one feature in a less than fully sintered bit body upon fully sintering the bit body is predicted and the at least one feature is formed on the less than fully sintered bit body at a location at least partially determined by the predicted positional error. In other embodiments, bit bodies of earth-boring rotary drill bits are designed to include a design drilling profile and a less than fully sintered bit body is formed including a drilling profile having a shape differing from a shape of the design drilling profile. Less than fully sintered bit bodies of earth-boring rotary drill bits are formed using such methods.

Abstract: A reactive foil is used to assemble the components of rock bit cutters and to affix cutting elements to rock bit bodies. A small pulse of localized energy ignites the foil in a fraction of second to deliver the necessary amount of heat energy to flow solder or braze and form a strong, true metallic joint. The reaction in the foil may be activated using optical, electrical, or thermal sources.

Abstract: Methods of forming cutting element pockets in blades of earth-boring tools include forming a first recess and a second recess intersecting at a location defining the a back of the pocket using a cutter oriented in a manner so as to avoid tool path interference with adjacent blades. A filler material is disposed in the second recess to the location of the back of the pocket. Earth-boring tools having such cutting element pockets are also disclosed.

Abstract: Methods for forming earth-boring tools include providing a metal or metal alloy bonding agent at an interface between a first element and a second element and sintering the first element, the second element, and the boding agent to form a bond between the first element and the second element at the interface. The methods may be used, for example, to bond together portions of a body of an earth-boring tool (which may facilitate, for example, the formation of cutting element pockets) or to bond cutting elements to a body of an earth-boring tool (e.g., a bit body of a fixed-cutter earth-boring drill bit or a cone of a roller cone earth-boring drill bit). At least partially formed earth-boring tools include a metal or metal alloy bonding agent at an interface between two or more elements, at least one of which may comprise a green or brown structure.

Abstract: Methods of forming cutter assemblies for use on earth-boring tools include sintering a cone structure to fuse one or more cutting elements thereto. In some embodiments, one or more green, brown, or fully sintered cutting elements may be positioned on a green or brown cone structure prior to sintering the cone structure to a final density. Cutter assemblies may be formed by such methods, and such cutter assemblies may be used in earth-boring tools such as, for example, earth-boring rotary drill bits and hole openers.

Abstract: A cutting element for use in drilling subterranean formations. The cutting element includes a superabrasive table mounted to a supporting substrate. The superabrasive table includes a two-dimensional cutting face having a cutting edge along at least a portion of its periphery, and a surface comprising a chamfer extending forwardly and inwardly from proximate a peripheral cutting edge at a first acute angle of orientation of greater than about 45° with respect to the longitudinal axis of the cutting element, and to no greater than a selected depth. The chamfer may be arcuate or planar, and of a dimension sufficient to ensure that a wear flat generated during use of the cutting element remains outside the inner boundary of the chamfer within the chamfer envelope, and small enough to maintain aggressive cutting characteristics for the cutter. Drill bits and drilling tools bearing the cutting elements are also disclosed.