Abstract: Tools, for example, fixed cutter drill bits, may be manufactured to include hard composite portions having reinforcing particles dispersed in a continuous binder phase and auxiliary portions that are more machinable than the hard composite portions. For example, a tool may include a hard composite portion having a machinability rating 0.2 or less; and an auxiliary portion having a machinability rating of 0.6 or greater in contact with the hard composite portion. The boundary or interface between the hard composite portion and the auxiliary portion may be designed so that upon removal of the most or all of the auxiliary portion the resultant tool has a desired geometry without having to machine the hard composite portion.

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. An infiltration chamber is defined at least partially by the mold and the funnel to receive and contain matrix reinforcement materials and a binder material used to form the infiltrated downhole tool. One or more thermal elements are positioned within at least one of the mold and the funnel, and the one or more thermal elements are in thermal communication with the infiltration chamber.

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 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 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: An infiltrated metal-matrix composite drill bit includes a bit body comprising a reinforced composite material including reinforcing particles infiltrated with a binder material. A plurality of cutting elements is coupled to an exterior of the bit body. A mandrel is positioned within the bit body and made of an M-based alloy selected from the group consisting of a titanium-based alloy, a nickel-based alloy, a copper-based alloy, a cobalt-based alloy, and a refractory metal-based alloy, wherein the element designated by “M” is the most prevalent element in the alloy composition. A shank is coupled to the mandrel.

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 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 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, 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: 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.

Abstract: The disclosure provides downhole tools with shaft regions that are hardened by a compressive residual stress created when an allotropic material in a precursor region transforms from a first allotrope to a second allotrope in response to heat, while continuing to occupy the same physical space. The disclosure further provides methods of forming such downhole tools.

Abstract: The disclosure provides rotary drill bits with bit head regions or other downhole tools with regions in which an allotropic material in a precursor region has been transformed from a first allotrope to a second allotrope in response to a trigger. The disclosure further provides methods of forming such downhole tools and methods of triggering an allotropic phase transformation during their use.

Abstract: An example insulation enclosure includes a support structure having at least an inner frame and providing a top end, a bottom end, and an opening defined in the bottom end for receiving a mold within an interior of the support structure, and a radiant barrier positioned within the interior of the support structure, the radiant barrier including a front surface arranged to face the mold and a back surface facing the support structure, wherein the radiant barrier interposes the mold and the support structure to redirect thermal energy radiated from the mold back towards the mold.

Abstract: Zonal heating and cooling during the production of matrix drill bits may be achieved with a system that includes a cavity defined within a mold assembly having a central axis; reinforcing particles and a binder material disposed within the cavity; and a plurality of induction coils about a periphery of the mold assembly, each induction coil being spaced from each other along the height of the mold assembly, wherein a first induction coil of the plurality of induction coils is arranged proximal to a portion of mold assembly containing a portion of the reinforcing particles and a second induction coil of the plurality of induction coils is arranged proximal to a portion of the mold assembly containing a portion of the binder material.

Abstract: A drill bit may include a matrix bit body and a plurality of cutting elements coupled to an exterior portion of the matrix bit body, wherein the matrix bit body includes matrix particles and precipitated intermetallic particles dispersed in a binder, at least some of the matrix particles having a diameter of 50 microns or greater, and at least some of the precipitated intermetallic particles having at least one dimension of 1 micron to 30 microns.

Abstract: A metal matrix composite tool includes a body having hard composite portion that includes reinforcing particles dispersed in a binder material. At least some of the reinforcing particles comprise a monolithic particle structure including a core having irregular outer surface features integral with the core.

Abstract: Tools, for example, fixed cutter drill bits, may be manufactured to include hard composite portions having reinforcing particles dispersed in a continuous binder phase and auxiliary portions that are more machinable than the hard composite portions. For example, a tool may include a hard composite portion having a machinability rating 0.2 or less; and an auxiliary portion having a machinability rating of 0.6 or greater in contact with the hard composite portion. The boundary or interface between the hard composite portion and the auxiliary portion may be designed so that upon removal of the most or all of the auxiliary portion the resultant tool has a desired geometry without having to machine the hard composite portion.

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: An infiltrated metal-matrix composite drill bit includes a bit body comprising a reinforced composite material including reinforcing particles infiltrated with a binder material. A plurality of cutting elements is coupled to an exterior of the bit body. A mandrel is positioned within the bit body and made of an M-based alloy selected from the group consisting of a titanium-based alloy, a nickel-based alloy, a copper-based alloy, a cobalt-based alloy, and a refractory metal-based alloy, wherein the element designated by “M” is the most prevalent element in the alloy composition. A shank is coupled to the mandrel.