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: 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: 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: 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.