A thermoelectric material of the present invention includes copper, tin, and sulfur, wherein a ratio A/B of the number A of copper atoms to the number B of tin atoms is 0.5 to 2.5 and a content of a metal element other than copper and tin is 5 mol % or less with respect to total metal elements. Additionally, the thermoelectric material of the present invention has a thermal conductivity less than 1.0 W/(m.Math.K) at 200 to 400° C.

In various embodiments, a metal alloy resistant to aqueous corrosion consists essentially of or consists of niobium with additions of tungsten, molybdenum, and one or both of ruthenium and palladium.

A hydrogen storage system includes a hydrogen storage alloy containment vessel comprising an external pressure containment vessel and a thermally conductive compartmentalization network disposed within the pressure containment vessel. The compartmentalization network creates compartments within the pressure vessel within which a hydrogen storage alloy is disposed. The compartmentalization network includes a plurality of thermally conductive elongate tubes positioned within the pressure vessel forming a coherent, tightly packed tube bundle providing a thermally conductive network between the hydrogen storage alloy and the pressure vessel. The hydrogen storage alloy is a non-pyrophoric AB.sub.2-type Laves phase hydrogen storage alloy having: an A-site to B-site elemental ratio of not more than 0.5; and an alloy composition including (in at %): Zr: 2.0-5.5, Ti: 27-31.3, V: 8.3-9.9, Cr: 20.6-30.5, Mn: 25.4-33.0, Fe: 1.0-5.9, Al: 0.1-0.4, and/or Ni: 0.0-4.0.

Disclosed herein are metal matrix composites and methods of making and use thereof. For example, disclosed herein are methods of making a metal matrix composite comprising a metal matrix reinforced by a high entropy alloy. The methods comprise mixing a first powder and a second powder to form a powder mixture, wherein the first powder comprises a plurality of particles comprising a metal and the second powder comprises a plurality of particles comprising a high entropy alloy. The methods further comprise compacting the powder mixture to form a pellet and adding the pellet to a molten metal, the molten metal comprising the metal in a molten state, thereby melting the pellet to form a molten mixture. The methods further comprise subjecting the molten mixture to an ultrasonic treatment and casting the ultrasonic treated mixture to form the metal matrix composite.

The present invention provides a method of in situ 4D printing of high-temperature materials including 3D printing a structure of an ink including a precursor. The structure is treated with controlled high energy flow to create a portion which has a different coefficient of thermal expansion/thermal shrinkage ratio. The structure is heated and the difference in the coefficient of thermal expansion creates an interface stress to cause a selected level of deformation. Alternatively, two structures with different coefficients of expansion/thermal shrinkage ratio may be printed. Thermal treatment of the two structures creates an interface stress to cause a selected level of deformation.

Systems and methods discussed herein relate to Zintl-type thermoelectric materials, including a p-type thermoelectric material according to the formula AM.sub.yX.sub.y, and includes at least one of calcium (Ca), europium (Eu), ytterbium (Yb), and strontium (Sr), and has a ZT of the above about 0.60 above 675K. The n-type thermoelectric component includes magnesium (Mg), tellurium (Te), antimony (Sb), and bismuth (Bi) according to the formula Mg.sub.3.2Sb.sub.1.3Bi.sub.0.5-xTe.sub.x that has an average ZT above 0.8 from 400K to 800K. The p-type and n-type materials discussed herein may be used alone, in combination with other materials, or in combination with each other in various configurations.

Provided is a brazing filler material for bonding iron-based sintered member that includes a sintered compact containing Cu, Mn, and a remainder of Ni and unavoidable impurities, and an oxide film formed on a surface of the sintered compact. An oxygen concentration may account for not less than 0.1% by mass of a total amount of the brazing filler material. The oxide film may contain Mn.

A metal composition that includes a metal component and a flux. The metal component is composed of a first metal powder of a Sn-based metal, and a second metal powder of a Cu-based metal that has a higher melting point than the Sn-based metal. The flux includes a rosin, a solvent, a thixotropic agent, an activator, and the like. When the metal composition is heated to a temperature equal to or higher than the melting point of the first metal powder, the first metal powder is melted. The melted Sn and the CuNi alloy powder produce an intermetallic compound phase of a CuNiSn alloy through a TLP reaction.

A titanium-free cobalt-chromium alloy for a powder, contains (in wt.%) C 0.40 -1.50%, Cr 24.0 - 32.0%, W 3.0 - 8.0%, Mo 0.1 - 5.0%, where 4.0 < W + Mo < 9.5 is satisfied by the content of W and Mo in wt.%, Nb max. 0.5%, Ta max. 0.5 %, where Nb + Ta < 0.8 is satisfied by the content of Nb and Ta in wt.%, Ni 0.005 - 25.0%, Fe 0.005 -15.0%, where Ni + Fe > 3.0 is satisfied by the content of Ni and Fe in wt.%, Mn 0.005 -5.0%, Al max. 0.5%, N 0.0005 - 0.15%, Si < 0.3%, Cu max. 0.4%, O 0.0001 - 0.1%, P max. 0.015%, B max. 0.015%, S max. 0.015%, residual Co, and impurities resulting from the production process, in particular Zr max. 0.03% and Ti max. 0.025%.

A method for making an article is disclosed. The method involves inputting a digital model of an article into an additive manufacturing apparatus comprising an energy source. The additive manufacturing apparatus applies energy from the energy source to successively applied incremental quantities of a powder to fuse the powder to form the article corresponding to the digital model. The powder includes an aluminum alloy having 2.00-10.00 wt. % cerium, 0.50-2.50 wt. % titanium, 0-3.00 wt. % nickel, 0-0.75 wt. % nitrogen, 0-0.05 wt. % other alloying elements, and the balance of aluminum, based on the total weight of the aluminum alloy.