Disclosed herein is method for making a wire comprising contacting a first end of a first superconducting wire with a second end of a second superconducting wire, wherein the superconducting wire comprises a superconducting filament having a superconducting composition comprising magnesium diboride; heating the first end of the first superconducting wire with the second end of the second superconducting wire at a point to form a joint, wherein the superconducting filament having the superconducting composition is in continuous electrical contact with any other part of the superconducting filament after the formation of the joint.

A method for forming a dispersion-strengthened material containing nanoparticles that are uniformly dispersed in a matrix phase. The method includes adding nanoparticles and a molten material to a container to form a pool within the container and rotating the container to create a convection vortex in the pool. The convection vortex is sufficient to cause the nanoparticles to be incorporated into the molten material so as to yield a molten composite material, and further causes the molten composite material to be ejected from the container. The molten composite material is then cooled to form a solid composite body comprising a uniform dispersion of the nanoparticles.

A casting system and method for producing a metal casting is provided. The metal casting can comprise a fine-grain, homogeneous microstructure that is essentially oxide- and sulfide-free, segregation defect free, and essentially free of voids caused by air entrapped during solidification of the metal from a liquidus state to a solid state. The casting system can comprise an electroslag refining system; a nucleated casting system; and a cooling system that cools the metal casting so as to cool a liquidus portion of the metal casting. The metal casting is cooled in a manner sufficient to provide a microstructure that comprises a fine-grain, homogeneous microstructure that is essentially oxide- and sulfide-free, segregation defect free, and essentially free of voids caused by air entrapped during solidification from a liquidus state to a solid state.

An electroslag refining apparatus includes upper and lower integral crucibles, with the lower crucible having a drain. In situ hot start is effected by depositing in the lower crucible a pre-refined starter. The starter is melted in the lower crucible to form a starter pool, and slag is deposited atop the starter pool for being melted thereby to develop a slag pool thereatop. An ingot electrode is lowered through the upper crucible to immerse a tip thereof into the slag pool. The electrode is powered to effect resistance heating of the slag pool to melt the electrode tip. The slag and starter pools are increased in volume into the upper crucible, with the drain then being opened to effect steady state operation.

An inspection apparatus for water flow testing of cooling passageways in gas turbine buckets provides observable visual determination of whether any blockages were formed during the manufacturing or refurbishing processes. The inspection apparatus includes a manifold block and manifold control valve mounted on a platform and adapted to engage the root end of a turbine bucket and supply fluid therethrough. The turbine bucket is affixed to the platform with a holder. The fluid exiting at the tip of the turbine bucket is visible and any blockages in the passageways will be easily discerned by the absence or paucity of fluid flow at the tip. Fluid is supplied to the manifold block by a pressure regulated fluid supply line with a control valve and a flow meter. An air supply line is also connected to the manifold block to supply air through the passageways to remove residual fluid from the bucket.