The disclosure provides aluminum alloys having varying ranges of alloying elements and properties.

An aluminum alloy material according to an embodiment of the present invention is an aluminum alloy including a grain boundary and a plurality of grains divided by the grain boundary, and having a face-centered cubic crystal structure, and includes a band formed by employing one or more non-metallic elements selected from oxygen (O), carbon (C) and nitrogen (N) in an aluminum matrix. Each of the grains includes a plurality of sub-grains divided by a low-angle grain boundary (LAGB), and a band positioned at the low-angle grain boundary may form a coherent interface with an aluminum matrix. Since a plurality of dislocations already are present in the band, a dislocation cell size is reduced during plastic deformation, which greatly contributes to an improvement in elongation. Such an aluminum alloy material can be subjected to cold rolling at a high reduction rate, and as a result, a plate having significantly improved elongation can be obtained.

The present invention provides a thermoelectric material excellent in heat resistance with less degradation of thermoelectric characteristics even in a high temperature environment. The thermoelectric material comprises a compound represented by a chemical formula Mg.sub.2Si.sub.1-xSn.sub.x (0<x<1) wherein at least one of the Si site and the Sn site of the compound is replaced with at least one of Sb and Bi, and an added Fe.

The disclosure relates to the technical field of alloys, and in particular to a titanium alloy with a gradient microstructure and a preparation method thereof Two new gradient microstructures different from the existing microstructure in titanium alloy are designed for the first time by an ingenious three-step heat treatment scheme, specifically, the gradient lamellar microstructure and gradient tri-modal microstructure. Compared with the regular uniform lamellar microstructure, the titanium alloy with gradient lamellar microstructure can achieve the simultaneous improvement of strength and ductility. Compared with the regular bimodal microstructure, the strength of a titanium alloy with a gradient tri-modal microstructure can be increased by about 10%, and the ductility is slightly reduced.

The disclosure relates to the technical field of alloys, and in particular to a titanium alloy with a gradient microstructure and a preparation method thereof Two new gradient microstructures different from the existing microstructure in titanium alloy are designed for the first time by an ingenious three-step heat treatment scheme, specifically, the gradient lamellar microstructure and gradient tri-modal microstructure. Compared with the regular uniform lamellar microstructure, the titanium alloy with gradient lamellar microstructure can achieve the simultaneous improvement of strength and ductility. Compared with the regular bimodal microstructure, the strength of a titanium alloy with a gradient tri-modal microstructure can be increased by about 10%, and the ductility is slightly reduced.

The present disclosure provides a high-strength and high-plasticity casting high-entropy alloy (HEA), having a general formula of Al.sub.aCo.sub.bCr.sub.cTi.sub.dFe.sub.eNi.sub.fCu.sub.g, where 6.0<a≤8.0, 18.0<b≤23.0, 7.5≤c<12.5, 2.0<d≤8.5, 15.5<e≤20.0, 28.0<f≤37.0, 0.2<g≤10.0, and a+b+c+d+e+f+g=100. The casting HEA can be prepared in one step and has excellent mechanical properties. The various metal raw materials are environmental-friendly and suitable for large-scale industrial production.

The present disclosure provides a high-strength and high-plasticity casting high-entropy alloy (HEA), having a general formula of Al.sub.aCo.sub.bCr.sub.cTi.sub.dFe.sub.eNi.sub.fCu.sub.g, where 6.0<a≤8.0, 18.0<b≤23.0, 7.5≤c<12.5, 2.0<d≤8.5, 15.5<e≤20.0, 28.0<f≤37.0, 0.2<g≤10.0, and a+b+c+d+e+f+g=100. The casting HEA can be prepared in one step and has excellent mechanical properties. The various metal raw materials are environmental-friendly and suitable for large-scale industrial production.

A multi-component system alloy includes titanium, zirconium, niobium, molybdenum, and tantalum, and further the multi-component system alloy includes at least one selected from the group consisting of hafnium, tungsten, vanadium, and chromium, wherein the alloy satisfies Mo equivalent ≧ 13.5, and the alloy is a single-phase solid solution, a two-phase solid solution, or an alloy in which a main phase is a solid solution phase.

A multi-component system alloy includes titanium, zirconium, niobium, molybdenum, and tantalum, and further the multi-component system alloy includes at least one selected from the group consisting of hafnium, tungsten, vanadium, and chromium, wherein the alloy satisfies Mo equivalent ≧ 13.5, and the alloy is a single-phase solid solution, a two-phase solid solution, or an alloy in which a main phase is a solid solution phase.

Disclosed are a copper alloy strip having high heat resistance and thermal dissipation properties which is suitable for a material for shield cans to solve heating of mobile devices, a material for vehicles and semiconductor lead frames, and a material for electrical and electronic parts, such as connectors, relays, switches, etc., widely used in industries including vehicles, and a method of preparing the same.