An electrochemical cell is described, including an anodic chamber and a cathodic chamber separated by an electrolyte separator tube, all contained within a cell case. The cell also includes an electrically insulating ceramic collar positioned at an opening of the cathodic chamber, and defining an aperture in communication with the opening; along with a cathode current collector assembly; and at least one metallic ring that has a coefficient of thermal expansion (CTE) in the range of about 3 to about 7.5 ppm/° C., contacting at least a portion of a metallic component within the cell, and an adjacent ceramic component. An active braze alloy composition attaches and hermetically seals the ring to the metallic component and the collar. Sodium metal halide batteries that contain this type of cell are also described, along with methods for sealing structures within the cell.

The present disclosure relates to new materials comprising Al, Co, Cr, and Ni. The new materials may realize a single phase field of a face-centered cubic (fcc) solid solution structure immediately below the solidus temperature of the material. The new materials may include at least one precipitate phase and have a solvus temperature of at least 1000° C. The new materials may include 2.2-8.6 wt. % Al, 4.9-65.0 wt. % Co, 4.3-42.0 wt. % Cr, and 4.8-88.6 wt. % Ni. In one embodiment, the precipitate is selected from the group consisting of the L1.sub.2 phase, the B2 phase, the sigma phase, the bcc phase, and combinations thereof. The new alloys may realize improved high temperature properties.

Nickel base superalloys, including in some embodiments 5% to 7% Fe, which were previously developed and used for their corrosion resistance, also possess favorable characteristics for use as a braze filler in repair or joining of superalloy substrates, such as those used to form turbine engine blades and vanes, heat exchangers, vessels, and piping. In particular, such corrosion-resistant nickel base superalloys have favorable characteristics for wide-gap brazing of gaps greater than one millimeter in superalloy substrates that preserves favorable material properties throughout the braze region in the substrate.

An electrode (10) is presented including a sheath (14) formed of a ductile material, an outer coating (16) including a flux material, and a core (12) including at least one of flux material and alloying material. The ductile material may be an extrudable subset of elements of a desired superalloy material and the alloying material may include elements that complement the ductile material to form a desired superalloy material when the electrode is melted. The outer coating may be formed of a flexible bonding material or it may be segmented (18, 20) to facilitate bending the electrode onto a spool. Any hygroscopic material of the electrode may be included in the core to protect it from exposure to atmospheric moisture.

A superalloy component such as a gas turbine engine blade (40) having a ceramic thermal barrier coating (41) is repaired using a textured repair foil (30). A degraded region of the thermal barrier coating is removed (14) and the underlying superalloy material surface is prepared (16) for re-coating. The repair foil is includes a layer of boron-free braze material (34) and a layer of superalloy material (32) having a textured surface (36). The foil is brazed (18) to the prepared surface during a solution heat treatment effective to homogenize the braze (20). A new area of thermal barrier coating (46) is applied over the foil with a bond that is enhanced by the texturing of the foil surface.

This glass bonding material (21) is made of a cladding material (1) in which at least a first layer (11) made of an Al-based alloy and configured to be bonded to glass and a second layer (12) made of an Fe—Ni based alloy having a thermal expansion coefficient from 30° C. to 400° C. of 11.5×10.sup.−6 (K.sup.−1) or less are bonded.

This disclosure includes the description of a braze alloy composition. The braze composition contains nickel, about 5% by weight to about 25% by weight germanium; and about 1% by weight to about 4% by weight boron. The composition has an amorphous structure, and is free of silicon.

An active braze alloy composition is described, including nickel; or a combination of nickel and cobalt; about 2% by weight to about 30% by weight germanium; and about 1% by weight to about 5% by weight boron and about 0.5% by weight to about 5% by weight of at least active element. The composition is free of silicon. Braze alloy joints formed of the braze alloy composition, and located in various devices, structures, and machines, are also described. A related method for repairing a crack or other cavity within a metal component, using the braze composition, is further described.

A nickel-based superalloy with an increased oxidation resistance, power, and welding method, is provided. As a result of the addition of hafnium, no precipitation phases occur in the nickel-based superalloy and the proportions of chromium (Cr) and aluminium (Al) lead to a slightly reduced y′-content, thus achieving good oxidation resistance and weldability.

Properties and performance of weld material between metals in a weldment is controlled by modifying one or more of the nitrogen content and the carbon content to produce carbide (e.g. MC-type), nitride and/or complex carbide/nitride (e.g. MX-type) type precipitates. Fusion welding includes (i) adjusting shield gas composition to increase nitrogen/carbon gas and nitride/carbide species, (ii) adjusting composition of nitrogen/carbon in materials that participate in molten welding processes, (iii) direct addition of nitrides/carbides (e.g. powder form), controlled addition of nitride/carbide forming elements (e.g. Ti, Al), or addition of elements that increase/impede solubility of nitrogen/carbon or nitride/carbide promoting elements (e.g. Mn), and (iv) other processes, such as use of fluxes and additive materials. Weld materials have improved resistance to different cracking mechanisms (e.g., hot cracking mechanisms and solid state cracking mechanisms) and improved tensile related mechanical properties.