Abstract: Hardfacing materials include a polymer matrix material and particles of hard material embedded within and dispersed throughout the polymer matrix material. Earth-boring tools include a tool body and a hardfacing material on at least a portion of a surface of the body, wherein the hardfacing material includes a polymer matrix material and particles of hard material embedded within and dispersed throughout the polymer matrix material. Methods of applying hardfacing material to an earth-boring tool comprise mixing hard particles with a polymer precursor material to form a paste, applying the paste to a surface of an earth-boring tool, and curing the polymer precursor material to form a hardfacing material on the surface of the earth-boring tool.

Abstract: Magnetic sample holders for abrasive operations include an array of magnets embedded in a matrix material. Each magnet of the array is positioned between about 0 mm and about 4 mm from at least one adjacent magnet of the array. Exposed surfaces of the magnets of the array are coplanar with a planar working surface of the matrix material. Methods of forming a polycrystalline diamond compact element include magnetically securing an alloy sample to an array of magnets embedded in a matrix. Each of the magnets of the array is within about 4 mm of at least one adjacent magnet of the array. A portion of the alloy sample is abraded away, and the alloy sample is positioned proximate to diamond grains and a substrate. The alloy sample, diamond grains, and substrate are subjected to a high pressure/high temperature process to sinter the diamond grains.

Abstract: Methods of repairing earth-boring tools may involve providing wear-resistant material over a temporary displacement member to repair a cutting element pocket in a body and a depth-of-cut control feature using the wear-resistant material. In some embodiments, the wear-resistant material may comprise a particle-matrix composite material. For example, a hardfacing material may be built up over a temporary displacement member to form or repair a cutting element pocket and provide a depth-of-cut control feature. Earth-boring tools may include a depth-of-cut control feature comprising a wear-resistant material. The depth-of-cut control feature may be configured to limit a depth-of-cut of a cutting element secured within a cutting element pocket partially defined by at least one surface of the depth-of-cut control feature. Intermediate structures formed during fabrication of earth-boring tools may include a depth-of-cut control feature extending over a temporary displacement member.

Abstract: Hardfacing materials include a polymer matrix material and particles of hard material embedded within and dispersed throughout the polymer matrix material. Earth-boring tools include a tool body and a hardfacing material on at least a portion of a surface of the body, wherein the hardfacing material includes a polymer matrix material and particles of hard material embedded within and dispersed throughout the polymer matrix material. Methods of applying hardfacing material to an earth-boring tool comprise mixing hard particles with a polymer precursor material to form a paste, applying the paste to a surface of an earth-boring tool, and curing the polymer precursor material to form a hardfacing material on the surface of the earth-boring tool.

Abstract: A downhole tool for use in wellbores comprises a layer of hydrophobic material over a body, wherein the layer of hydrophobic material comprises a transition metal boride having a higher hydrophobicity than the body. The downhole tool may comprise a body having a composition and the layer of hydrophobic material comprising a discontinuous phase of the transition metal binder dispersed within a first continuous phase comprising a metal binder. The layer of material may be chemically bonded to the body. An interface between the body and the layer of material may comprise the transition metal boride dispersed within a second continuous phase comprising the metal binder and the composition of the body. Methods of forming downhole tools include forming such a layer of material at a surface of a body of a downhole tool.

Abstract: A component for a downhole tool includes a rotor and a hardfacing precursor. The hardfacing precursor includes a polymeric material, hard particles, and a metal. A hydraulic drilling motor includes a stator, a rotor, and a sintered hardfacing material on an outer surface of the rotor or an inner surface of the stator. Methods of applying hardfacing to surfaces include forming a paste of hard particles, metal matrix particles, a polymeric material, and a solvent. The solvent is removed from the paste to form a sheet, which is applied to a surface and heated. A component for a downhole tool includes a first hardfacing material, a second hardfacing material over the first hardfacing material and defining a plurality of pores, and a metal disposed within at least some of the pores. The metal has a melting point lower than a melting point of the second hardfacing material.

Abstract: Magnetic sample holders for abrasive operations include an array of magnets embedded in a matrix material. Each magnet of the array is positioned between about 0 mm and about 4 mm from at least one adjacent magnet of the array. Exposed surfaces of the magnets of the array are coplanar with a planar working surface of the matrix material. Methods of forming a polycrystalline diamond compact element include magnetically securing an alloy sample to an array of magnets embedded in a matrix. Each of the magnets of the array is within about 4 mm of at least one adjacent magnet of the array. A portion of the alloy sample is abraded away, and the alloy sample is positioned proximate to diamond grains and a substrate. The alloy sample, diamond grains, and substrate are subjected to a high pressure/high temperature process to sinter the diamond grains.

Abstract: A method of forming a down-hole tool comprises contacting at least a portion of at least one down-hole structure comprising at least one ceramic-metal composite material with a molten electrolyte comprising sodium tetraborate. Electrical current is applied to at least a portion of the at least one down-hole structure to form at least one borided down-hole structure comprising at least one metal boride material. Other methods of forming a down-hole tool, and a down-hole tool are also described.

Abstract: A method of forming a downhole tool comprises contacting at least one downhole structure comprising at least one metal material with a molten electrolyte comprising anhydrous sodium tetraborate. Electrical current is applied to at least a portion of the at least one downhole structure to form at least one borided downhole structure comprising at least one metal boride material. Other methods of forming a downhole tool, and a downhole tool are also described.

Abstract: A method includes disposing a braze material between a first body and a second body. The braze material includes a first composition and a second composition. The second composition has a melting point higher than the first composition. The braze material may be heated to a brazing temperature between the melting points of the first and second materials and maintaining the braze material at the brazing temperature for a period of time to transform a transient liquid phase to a solid phase, forming a bond between the first body and the second body. A braze material for securing solid bodies includes a first composition and a second composition. The first composition includes at least one element selected from the group consisting of indium, tin, zinc, and magnesium. An earth-boring tool includes a first body, a second body, and a braze material bonding the second body to the first body.

Abstract: A method includes disposing a braze material between a first body and a second body. The braze material includes a first composition and a second composition. The second composition has a melting point higher than the first composition. The method also includes heating the braze material to a brazing temperature between the melting points of the first and second materials and maintaining the braze material at the brazing temperature for a period of time to transform a transient liquid phase to a solid phase, forming a bond between the first body and the second body. A braze material for securing solid bodies includes a first composition and a second composition. The first composition includes at least one element selected from the group consisting of indium, tin, zinc, and magnesium. An earth-boring tool includes a first body, a second body, and a braze material bonding the second body to the first body.

Abstract: A hardfacing composition for downhole well tools, such as earth-boring bits, contains sintered ultrahard particles. The ultrahard particles consist of tungsten carbide grains, cobalt and vanadium. The ultrahard particles are dispersed within a matrix metal of iron, nickel or alloys thereof. The composition may also have sintered tungsten carbide particles of a larger size than the ultrahard particles. The ultrahard particles have a greater hardness than the sintered tungsten carbide particles. The ultrahard particles and the sintered tungsten carbide particles may be in a spherical pellet form. Other hard metal particles may be in the composition.

Abstract: An abrasive wear-resistant material includes a matrix and sintered and cast tungsten carbide pellets. A device for use in drilling subterranean formations includes a first structure secured to a second structure with bonding material. An abrasive wear-resistant material covers the bonding material. The first structure may include a drill bit body and the second structure may include a cutting element. A method for applying an abrasive wear-resistant material to a drill bit includes providing a bit, mixing sintered and cast tungsten carbide pellets in a matrix material to provide a pre-application material, heating the pre-application material to melt the matrix material, applying the pre-application material to the bit, and solidifying the material. A method for securing a cutting element to a bit body includes providing an abrasive wear-resistant material to a surface of a drill bit that covers a brazing alloy disposed between the cutting element and the bit body.

Abstract: A system and method for the automated or “robotic” application of hardfacing to a surface of a drill bit.

Abstract: Methods of repairing earth-boring tools may involve providing wear-resistant material over a temporary displacement member to repair a cutting element pocket in a body and a depth-of-cut control feature using the wear-resistant material. In some embodiments, the wear-resistant material may comprise a particle-matrix composite material. For example, a hardfacing material may be built up over a temporary displacement member to form or repair a cutting element pocket and provide a depth-of-cut control feature. Earth-boring tools may include a depth-of-cut control feature comprising a wear-resistant material. The depth-of-cut control feature may be configured to limit a depth-of-cut of a cutting element secured within a cutting element pocket partially defined by at least one surface of the depth-of-cut control feature. Intermediate structures formed during fabrication of earth-boring tools may include a depth-of-cut control feature extending over a temporary displacement member.

Abstract: A method includes disposing a braze material between a first body and a second body. The braze material includes a first composition and a second composition. The second composition has a melting point higher than the first composition. The method also includes heating the braze material to a brazing temperature between the melting points of the first and second materials and maintaining the braze material at the brazing temperature for a period time to transform a transient liquid phase to a solid phase, forming a bond between the first body and the second body. A braze material for securing solid bodies includes a first composition and a second composition. The first composition includes at least one element selected from the group consisting of indium, tin, zinc, and magnesium. An earth-boring tool includes a first body, a second body, and a braze material bonding the second body to the first body.

Abstract: A method for applying a non-magnetic, abrasive, wear-resistant hardfacing material to a surface of a drill string member includes providing a non-magnetic drill string member formed of a non-magnetic material, the drill string member having an outer surface. It also includes providing a non-magnetic hardfacing precursor material comprising a plurality of non-magnetic, sintered carbide pellets and a non-magnetic matrix material; heating a portion of the non-magnetic hardfacing precursor material to a temperature above the melting point of the matrix material to melt the matrix material. It further includes applying the molten non-magnetic matrix material and the plurality of non-magnetic, sintered carbide pellets to the exterior surface of the drill string member; and solidifying the molten non-magnetic matrix material to form a layer of a non-magnetic hardfacing material having a plurality of non-magnetic, sintered carbide pellets dispersed in the hardfacing material.

Abstract: A downhole tool for use in wellbores comprises a layer of hydrophobic material over a body, wherein the layer of hydrophobic material comprises a transition metal boride having a higher hydrophobicity than the body. The downhole tool may comprise a body having a composition and the layer of hydrophobic material comprising a discontinuous phase of the transition metal binder dispersed within a first continuous phase comprising a metal binder. The layer of material may be chemically bonded to the body. An interface between the body and the layer of material may comprise the transition metal boride dispersed within a second continuous phase comprising the metal binder and the composition of the body. Methods of forming downhole tools include forming such a layer of material at a surface of a body of a downhole tool.

Abstract: Methods of repairing earth-boring tools may involve providing wear-resistant material over a temporary displacement member to repair a cutting element pocket in a body and a depth-of-cut control feature using the wear-resistant material. In some embodiments, the wear-resistant material may comprise a particle-matrix composite material. For example, a hardfacing material may be built up over a temporary displacement member to form or repair a cutting element pocket and provide a depth-of-cut control feature. Earth-boring tools may include a depth-of-cut control feature comprising a wear-resistant material. The depth-of-cut control feature may be configured to limit a depth-of-cut of a cutting element secured within a cutting element pocket partially defined by at least one surface of the depth-of-cut control feature. Intermediate structures formed during fabrication of earth-boring tools may include a depth-of-cut control feature extending over a temporary displacement member.

Abstract: Methods for applying an abrasive wear-resistant material to a surface of a drill bit include providing a drill bit having a bit body formed of a material comprising one of steel material, particle-matrix composite material and cemented matrix material, mixing a plurality of ?40/+80 ASTM mesh dense sintered carbide pellets in a matrix material, heating the matrix material to a temperature above the melting point of the matrix material, applying the molten matrix material and at least some of the dense sintered carbide pellets to at least a portion of an exterior surface of the bit body; and solidifying the molten matrix material.