A drill-string liner element includes at least one hardbanding layer. The hardbanding layer includes one or more strands of filler metal, each having a width between 1 and 5 millimeters and deposited in adjacent manner to form a substantially continuous layer over a zone of the element. The hardness in the thickness of the layer varies by less than 10 HRC over the zone.

Earth-boring tools may include a body having blades protruding therefrom and at least one hardfacing pad secured to at least one blade. The at least one hardfacing pad may be located at least partially within a recess extending at least into the at least one blade body around a circumference of a gage region of the body and may include a plate, an abrasion-resistant material secured to the plate on a side of the plate opposite the body, and at least one spacer extending from the plate toward the body, such that the plate is spaced from the body by at least a thickness of the at least one spacer. A braze material may secure the at least one hardfacing pad to the at least one blade, the braze material extending around the at least one spacer and located between the plate and the body.

A method includes disposing a braze material adjacent a first body and a second body; heating the braze material and forming a transient liquid phase; and transforming the transient liquid phase to a solid phase and forming a bond between the first body and the second body. The braze material includes copper, silver, zinc, magnesium, and at least one material selected from the group consisting of nickel, tin, cobalt, iron, phosphorous, indium, lead, antimony, cadmium, and bismuth.

A method of manufacturing a roller cone includes machining a cone blank and thereby defining one or more land surfaces and one or more insert grooves on the cone blank, surface hardening the cone blank, and milling a plurality of recesses into at least one of the one or more land surfaces. The method further includes subjecting the cone blank to a quenching process, forming an insert hole at each recess, and inserting an insert into each insert hole.

Chemical methods, optionally in combination with physical methods, may be used to increase the strength of the bond formed by a braze material between a polycrystalline material and a hard composite. Such polycrystalline materials brazed to hard composites may be found in various wellbore tools include drill bit cutters. An exemplary method may include forming a bonding layer on a bonding surface of a polycrystalline material body that comprises a hard material, the bonding surface opposing a contact surface of the polycrystalline material body, and the bonding layer substantially formed by a [111] crystal structure of the hard material, a [100] crystal structure of the hard material, or a combination thereof; and brazing the bonding layer to a hard composite using a braze material.

A method of applying non-magnetic semi-helical hardbanding to a non-magnetic drill collar used in well-drilling operations is disclosed herein. The method involves applying semi-helical bands using Plasma Transferred Arc (PTA), laser hardfacing, or a similar thermal-welding technique. At least one non-magnetic alloy is used to form a set of evenly spaced single blades around the circumference of the drill collar. The blades are arranged such that no single blade extends around the full circumference of the collar.

A method for making a polycrystalline diamond compact (PDC). The method includes: 1) preparing a workblank of a polycrystalline diamond compact (PDC); and 2) thermally- or cold-etching the curved surface of the workblank of the polycrystalline diamond compact (PDC) using laser. The thermally- or cold-etching the curved surface of the workblank of the polycrystalline diamond compact (PDC) includes: employing a laser generator to produce a laser beam, expanding the laser beam, focusing the laser beam, to yield an energy concentration area on the surface of the workblank of the polycrystalline diamond compact, and etching the curved surface using the energy concentration area.

Disclosed are high strength tubular devices for use in oil and gas well drilling and completions, oil and gas well intervention, and/or production systems. The high strength tubular devices include a pipe component and a secondary layer on the surface of the pipe component. The secondary layer can be either a continuous or partial layer and includes a nanostructured alloy. Alloy compositions are disclosed. Methods for forming the tubular devices are disclosed. The secondary layer can be formed on the pipe component by welding or casting. The tubular devices can be used in conductors, casing, drill pipe, production tubing, pipeline and risers.

A cutting tool includes a supporting body and a cBN or PCD cutting edge tip attached to the supporting body via a 5-150 ?m braze joint. The supporting body is cemented carbide having 3-25 wt % of a metallic binder, optionally up to 25 wt % of carbides or carbonitrides of one or more elements of group 4, 5, or 6, and the rest WC. The metallic binder includes at least 40 wt % Ni, and the braze joint has, in the order from the supporting body, a first layer of TiC situated next thereto, with an average thickness of 10-400 nm, a second layer, with an average thickness of 0.5-8 ?m, having in average at least 5 wt % metallic Ni, in average 25-60 wt % metallic Cu and in average 15-45 wt % metallic Ti, and a third layer, with an average thickness of 4-145 ?m, having metallic Ag and metallic Cu.

Chemical methods, optionally in combination with physical methods, may be used to increase the strength of the bond formed by a braze material between a polycrystalline material and a hard composite. Such polycrystalline materials brazed to hard composites may be found in various wellbore tools include drill bit cutters. An exemplary method may include forming a bonding layer on a bonding surface of a polycrystalline material body that comprises a hard material, the bonding surface opposing a contact surface of the polycrystalline material body, and the bonding layer substantially formed by a [111] crystal structure of the hard material, a [100] crystal structure of the hard material, or a combination thereof; and brazing the bonding layer to a hard composite using a braze material.