Abstract: Drill bits and associated methods of manufacture and use employ a pre-diffused mandrel bonded to a composite metal-matrix material. The pre-diffused mandrel includes a chemically altered surface composition that enhances the bond with the composite metal-matrix component formed by infiltrating a metal-matrix component with a binder. The chemically altered surface may be configured to reduce binder-rich zones adjacent the mandrel, mechanically interlock the with the composite metal-matrix component or prevent the formation of brittle intermetallic particles along the bond.

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: Drill bits and associated methods of manufacture and use employ a pre-diffused mandrel bonded to a composite metal-matrix material. The pre-diffused mandrel includes a chemically altered surface composition that enhances the bond with the composite metal-matrix component formed by infiltrating a metal-matrix component with a binder. The chemically altered surface may be configured to reduce binder-rich zones adjacent the mandrel, mechanically interlock the with the composite metal-matrix component or prevent the formation of brittle intermetallic particles along the bond.

Abstract: An example insulation enclosure for cooling a mold includes a support structure having a top end, a bottom end, and an interior, the bottom end defining an opening for receiving a mold within the interior of the support structure, and insulation material supported by the support structure and extending at least from the bottom end to the top end, wherein one or more thermal properties of at least one of the support structure and the insulation material varies longitudinally from the bottom end to the top end. In some cases, the one or more thermal properties are further varied about a circumference of the support structure.

Abstract: An example insulation enclosure includes an outer shell having an open end and a top end, and an inner shell arranged within the outer shell and including a plurality of sidewall members and a top member. Each sidewall member is independently moveable relative to one another and to the top member, and the plurality of sidewall members and the top member each include a support member and insulation material positioned on the support member. One or more compliant devices arranged between the outer shell and at least one of the plurality of sidewall members and the top member, the one or more compliant devices biasing the at least one of the plurality of sidewall members and the top member against adjacent outer surfaces of a mold disposable within the inner shell.

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 insulation enclosure includes an outer shell having an open end and a top end, and an inner shell arranged within the outer shell and including a plurality of sidewall members and a top member. Each sidewall member is independently moveable relative to one another and to the top member, and the plurality of sidewall members and the top member each include a support member and insulation material positioned on the support member. One or more compliant devices arranged between the outer shell and at least one of the plurality of sidewall members and the top member, the one or more compliant devices biasing the at least one of the plurality of sidewall members and the top member against adjacent outer surfaces of a mold disposable within the inner shell.

Abstract: An example insulation enclosure for cooling a mold includes a support structure having a top end, a bottom end, and an interior, the bottom end defining an opening for receiving a mold within the interior of the support structure, and insulation material supported by the support structure and extending at least from the bottom end to the top end, wherein one or more thermal properties of at least one of the support structure and the insulation material varies longitudinally from the bottom end to the top end. In some cases, the one or more thermal properties are further varied about a circumference of the support structure.