Abstract: A metal matrix composite tool that includes a hard composite portion comprising a reinforcement material infiltrated with a binder material, wherein the reinforcement material comprises a refractory metal component dispersed with reinforcing particles, wherein a surface roughness of the reinforcing particles is at least two times greater than the refractory metal component, wherein the refractory metal component has a failure strain of at least 0.05 and a shear modulus of 200 GPa or less, and wherein the reinforcing particles have a failure strain of 0.01 or less but at least five times less than the failure strain of the refractory metal component, and the reinforcing particles have a shear modulus of greater than 200 GPa and at least two times greater than the shear modulus of the refractory metal component. The reinforcing particles may comprise an intermetallic, a boride, a carbide, a nitride, an oxide, a ceramic, and/or a diamond.

Abstract: An example insulation enclosure includes a support structure having a top end, a top wall provided at the top end, a bottom end, and an opening defined at the bottom end for receiving a mold within an interior of the support structure. Rigid insulation material may be supported by the support structure and extending between the top and bottom ends and across the top end. The rigid insulation material may extend between the top and bottom ends and consist of one or more sidewall insulation loops that extend along a circumference of the insulation enclosure.

Abstract: An example mold assembly for fabricating an infiltrated downhole tool includes a mold forming a bottom of the mold assembly, and a funnel operatively coupled to the mold and having an inner wall, an outer wall, and a cavity defined between the inner and outer walls. An infiltration chamber is defined at least partially by the mold and the funnel. The inner wall faces the infiltration chamber and the outer wall forms at least a portion of an outer periphery of the mold assembly.

Abstract: A fixed-cutter drill bit is provided that includes a metal-matrix composite body having at least one metal-matrix composite blade. Cutters are disposed on the blades. A ductile insert is partially disposed within the body and has an exposed surface. The ductile insert has a greater ductility than the metal-matrix composite thereby alleviating stresses imposed on the metal-matrix composite during manufacture of the bit or drilling.

Abstract: A wellbore tool may be formed, at least in part, by a fiber-reinforced hard composite portion that comprises a binder, matrix particles, and reinforcing fibers. The reinforcing fibers may have an aspect ratio ranging from equal to a critical aspect ratio (Ac) to 15 times greater than the Ac. In the formula, Ac=?f/(2?c), ?f is an ultimate tensile strength of the reinforcing fibers, and ?c is an interfacial shear bond strength between the reinforcing fiber and the binder or a yield stress of the binder, whichever is lower.

Abstract: A wellbore tool may be formed, at least in part, by a fiber-reinforced hard composite portion. The fiber-reinforced hard composite portion can include reinforcing particles and reinforcing fibers dispersed in a binder, wherein the reinforcing fibers have an aspect ratio ranging from 1 to 15 times a critical aspect ratio (Ac). The critical aspect ratio can be determined using the equation Ac=?f/(2?c), wherein ?f is an ultimate tensile strength of the reinforcing fibers, and ?c is an interfacial shear bond strength between the reinforcing fiber and the binder or a yield stress of the binder, whichever is lower.

Abstract: A hard composite composition may comprise a binder and a polymodal blend of matrix powder. The polymodal blend of matrix powder may have at least one first local maxima at a particle size of about 0.5 nm to about 30 ?m, at least one second local maxima at a particle size of about 200 ?m to about 10 mm, and at least one local minima between a particle size of about 30 ?m to about 200 ?m that has a value that is less than the first local maxima.

Abstract: A drill bit in which a cutting element support shoe is mounted to a drill bit member so that it covers a portion of a number cutting elements while leaving the cutting edges of cutting elements exposed to the formation. The drill bit member may include a bit body, blade, arm, or roller, for example. The drill bit member may include a recess into which the cutting element support shoe is received. Cutting element support shoe provides mechanical holding of the cutting elements within their pockets in addition to conventional brazing or other mounting techniques. Once installed, a hard facing material may be applied over the cutting element support shoe as appropriate for increased erosion resistance. In one embodiment, the cutting element support shoe is sized so that when mounted to the drill bit member it is elastically deformed, thereby providing additional cutter retaining force upon attachment.

Abstract: An example mold assembly for fabricating an infiltrated downhole tool includes a mold forming a bottom of the mold assembly, and a funnel operatively coupled to the mold and having an inner wall, an outer wall, and a cavity defined between the inner and outer walls. An infiltration chamber is defined at least partially by the mold and the funnel. The inner wall faces the infiltration chamber and the outer wall forms at least a portion of an outer periphery of the mold assembly.

Abstract: An example cooling system for a mold assembly includes a quench plate that defines one or more discharge ports and one or more recuperation ports. A fluid is circulated from the one or more discharge ports to the one or more recuperation ports to cool the mold assembly. A blocking ring is positioned on the quench plate and defines a central aperture for receiving a bottom of the mold assembly. An insulation enclosure having an interior for receiving the mold assembly is positioned on the blocking ring. The blocking ring prevents vapor generated by the fluid contacting the bottom of the mold assembly from migrating into the interior of the insulation enclosure.

Abstract: A reinforcing metal blank may be used to form metal matrix composite (MMC) drill bits. For example, an MMC drill bit may include a shank attached to a reinforcing metal blank that extends into a bit body comprising a metal matrix composite, wherein the reinforcing metal blank comprises reinforcing structures that are positioned along at least a portion of an inner surface and/or at least a portion of an outer surface of the reinforcing metal blank and extend into the metal matrix composite; and a plurality of cutting elements coupled to an exterior portion of the bit body.

Abstract: Continuous fiber-reinforced hard composites may be useful in mitigating crack propagation in downhole tools. In some instances, a wellbore tool may be formed at least in part by a continuous fiber-reinforced hard composite portion. The continuous fiber-reinforced hard composite portion includes a binder material continuous phase with reinforcing particles and continuous fibers contained therein, wherein the continuous fibers have an aspect ratio at least 15 times greater than a critical aspect ratio (Ac). The critical aspect ratio can be determined using the equation Ac=?f/(2?c), ?f is an ultimate tensile strength of the continuous fibers, and ?C is a lower of (1) an interfacial shear bond strength between the continuous fibers and the binder material and (2) a yield stress of the binder material.

Abstract: A metal matrix composite (MMC) may be formed with two or more portions each having different reinforcing particles that enhance strength, wear resistance, or both of their respective portions of the MMC. Selective placement of the different reinforcing particles may be achieved using magnetic members. For example, in some instances, forming an MMC may involve placing reinforcement materials within an infiltration chamber of a mold assembly, the reinforcement materials comprising magnetic reinforcing particles and non-magnetic reinforcing particles; positioning one or more magnetic members relative to the mold assembly to selectively locate the magnetic reinforcing particles within the infiltration chamber with respect to the non-magnetic reinforcing particles; and infiltrating the reinforcement materials with a binder material to form a hard composite.

Abstract: A vented blank may be useful in the production of a matrix bit body. A mold assembly for use in producing a matrix bit body may include a cavity defined within the mold assembly. A core and a matrix material are disposed within the cavity. A metal blank is disposed about the core and supported at least partially by the matrix material such that the metal blank extends above the matrix material. A vent extends from the metal blank, defining an annular space between the vent and the mold assembly.

Abstract: A method for fabricating an infiltrated metal-matrix composite (MMC) tool includes positioning at least one boundary form within an infiltration chamber of a mold assembly and thereby segregating the infiltration chamber into at least a first zone and a second zone. Reinforcement materials are deposited into the infiltration chamber and include a first composition loaded into the first zone and a second composition loaded into the second zone. The first and second compositions are then infiltrated with at least one binder material to provide the infiltrated MMC tool with differing mechanical, chemical, physical, thermal, atomic, magnetic, or electrical properties between the first and second zones.

Abstract: A mold assembly system includes a mold assembly that defines an infiltration chamber used for forming an infiltrated metal-matrix composite (MMC) tool. Reinforcement materials are deposited within the infiltration chamber, and a binder material is used to infiltrate the reinforcement materials. At least one preformed mesh is positioned within the infiltration chamber and embedded within the reinforcement materials. The at least one preformed mesh includes a porous body and provides skeletal reinforcement to the infiltrated MMC tool following infiltration.

Abstract: A mold assembly system includes a mold assembly that defines an infiltration chamber used for forming an infiltrated metal-matrix composite (MMC) tool, and at least one boundary form positioned within the infiltration chamber and segregating the infiltration chamber into at least a first zone and a second zone. Reinforcement materials are deposited within the infiltration chamber and include a first composition loaded into the first zone and a second composition loaded into the second zone. At least one binder material infiltrates the first and second compositions, wherein infiltration of the first and second compositions results in differing mechanical, chemical, physical, thermal, atomic, magnetic, or electrical properties between the first and second zones in the infiltrated MMC tool.

Abstract: An earth-boring drill bit includes a bit body having a powder component and a binder. The powder component includes a plurality of nanotubes disposed on a surface of at least one particle of the powder component.

Abstract: A hard composite composition may comprise a binder and a polymodal blend of matrix powder. The polymodal blend of matrix powder may have at least one first local maxima at a particle size of about 0.5 nm to about 30 ?m, at least one second local maxima at a particle size of about 200 ?m to about 10 mm, and at least one local minima between a particle size of about 30 ?m to about 200 ?m that has a value that is less than the first local maxima.

Abstract: A drill bit formed of a binder comprising a copper nickel manganese alloy is disclosed. The binder has an increased content of manganese, which improves the strength and toughness of the drill bit. Manganese forms a solid solution with copper in the alloy, as well as forming an intermetallic with the nickel constituent. The formation of the MnNi inter-metallic also serves to improve the erosion resistance of the binder alloy and thus the overall erosion resistance of the MMC.