Abstract: A CaTiO3-based oxide thermoelectric material and a preparation method thereof are disclosed. The CaTiO3-based oxide thermoelectric material has a chemical formula of Ca1-xLaxTiO3, where 0<x?0.4. The present disclosure makes it possible to prepare a CaTiO3-based thermoelectric material with properties comparable to n-type ZnO, CaTiO3, SrTiO3 and other oxide thermoelectric materials. Among them, the La15 sample has a power factor reaching up to 8.2 ?Wcm?1K?2 (at about 1000 K), and a power factor reaching up to 9.2 ?Wcm?1K?2 at room temperature (about 300 K); and a conductivity reaching up to 2015 Scm?1 (at 300 K). The CaTiO3-based oxide thermoelectric material exhibits the best thermoelectric performance among calcium titanate ceramics. The method for preparing the CaTiO3-based oxide thermoelectric material of the present disclosure is simple in process, convenient in operation, low in cost, and makes it possible to prepare a CaTiO3-based ceramic sheet with high thermoelectric performance.

Abstract: A CaTiO3-based oxide thermoelectric material and a preparation method thereof are disclosed. The CaTiO3-based oxide thermoelectric material has a chemical formula of Ca1-xLaxTiO3, where 0<x?0.4. The present disclosure makes it possible to prepare a CaTiO3-based thermoelectric material with properties comparable to n-type ZnO, CaTiO3, SrTiO3 and other oxide thermoelectric materials. Among them, the La15 sample has a power factor reaching up to 8.2 ?Wcm?1K?2 (at about 1000 K), and a power factor reaching up to 9.2 ?Wcm?1K?2 at room temperature (about 300 K); and a conductivity reaching up to 2015 Scm?1 (at 300 K). The CaTiO3-based oxide thermoelectric material exhibits the best thermoelectric performance among calcium titanate ceramics. The method for preparing the CaTiO3-based oxide thermoelectric material of the present disclosure is simple in process, convenient in operation, low in cost, and makes it possible to prepare a CaTiO3-based ceramic sheet with high thermoelectric performance.

Abstract: A radiation resistant high-entropy alloy is provided, having an FCC structure, defined by general formula of FeCoNiVMoTixCry, where 0.05?x?0.2, 0.05?y?0.3, x and y are molar ratios. The radiation resistant high-entropy alloy has excellent irradiation resistance and is subject to radiation hardening saturation at high temperature (600° C.) in a condition of a high dose (1-3×1016 ions/cm2) of helium ion irradiation. A lattice constant of the high-entropy alloy decreases abnormally after irradiation. The high-entropy alloy has a radiation resistance far higher than that of a conventional alloy and has an excellent plasticity and specific strength. In an as-cast condition and at room temperature, a tensile break strength of the high-entropy alloy is higher than 580 MPa, an engineering strain (a tensile elongation) of the high-entropy alloy is greater than 30%.

Abstract: The present disclosure relates to the technical field of dissimilar welding of Cu and a steel, and in particular to a welding wire for dissimilar welding of Cu and a steel and a preparation method thereof and a method for welding Cu and a steel. The present disclosure provides a welding wire for dissimilar welding of Cu and a steel, including, in percentages by mass, 5-25% of iron phase, less than 0.1% of inevitable impurities, and copper matrix. The welding wire of the present disclosure, containing two elements, i.e. copper and iron, is conducive to the mixing of the two phases—copper and iron—during the welding process, to form a mutual soluble region, thereby makes it possible to greatly increase the weldability, reduce the width of the weld, effectively overcome the tendency of cracks, and thus to ensure the formed weld with a high crack resistance.

Abstract: The present invention provides a radiation resistant high-entropy alloy and a preparation method thereof. A general formula of the radiation resistant high-entropy alloy is TiZrHfVMoTaxNby, where 0.05?x?0.25, 0.05?y?0.5, and x and y are molar ratios. The preparation method of the radiation resistant high-entropy alloy comprises the following steps: mixing Ti, Zr, Hf, V, Mo, Ta, and Nb in order, and conducting vacuum levitation induction melting or vacuum arc melting, to obtain the radiation resistant high-entropy alloy. The high-entropy alloy in the present invention has an excellent irradiation resistance, and does not suffer radiation hardening damage under simulated helium ion irradiation. When helium bubbles are of same sizes as those of conventional alloy, the bubble density of the high-entropy alloy is far lower than that of the conventional alloy, and the lattice constant thereof decreases abnormally after irradiation.

Abstract: The present invention provides a copper alloy with high strength, high electrical conductivity, and high wear resistance and a preparation method thereof. The copper alloy includes 0.7 to 1.5 wt % of Cr, 0.2 to 0.6 wt % Zr and Hf, and Cu as balance. The present invention further discloses a preparation method of the copper, and the method includes the following steps: conducting hot-rolling and then solution treatment, removing a surface oxidation layer, and successively conducting first rolling, first aging treatment, second rolling, and second aging treatment. In the present invention, the preparation method of the copper alloy with high strength, high electrical conductivity, and high wear resistance can effectively avoid mutual interference between hard second phase particles and alloying elements, and the copper alloy with high strength, high electrical conductivity, and high wear resistance prepared by using the method has excellent wear resistance and mechanical properties.

Abstract: The present invention provides a high-entropy Half-Heusler thermoelectric material with a low lattice thermal conductivity and a preparation method thereof. The general formula of the high-entropy Half-Heusler thermoelectric material with a low lattice thermal conductivity is ZrxHf1-xNiyPd1-ySn, where x is equal to 0.6 to 0.8, and y is equal to 0.8 to 0.9. The preparation method of the high-entropy Half-Heusler thermoelectric material with a low lattice thermal conductivity comprises the following steps: preparing and mixing materials according to the general formula of Zr0.7Hf0.3Ni0.85Pd0.15Sn, putting the mixed raw materials in a levitation melting for melting, grinding the obtained ingot into powder and drying it, and sintering the powder by using spark plasma sintering into a bulk high-entropy Half-Heusler thermoelectric material with a low lattice thermal conductivity.

Abstract: The invention relates to a process for manufacturing a ZrNiSn-based half-Heusler thermoelectric material and regulating antisite defects therein, including the steps of: mixing zirconium (Zr), nickel (Ni), and stannum (Sn) at an atomic ratio of Zr: Ni: Sn=1:1:1; forming an ingot by melting the mixture in a levitation melting furnace; milling the ingot to form a milled powder followed by drying; sintering the dried powder by spark plasma sintering; and placing the sintered powder in a vacuum vessel to be subjected to heat treatment and then quenching treatment to obtain the ZrNiSn-based half-Heusler thermoelectric material. The process is simple, easy to control, and results in a single phase ZrNiSn-based half-Heusler thermoelectric material with antisite defects.

Abstract: A radiation resistant high-entropy alloy is provided, having an FCC structure, defined by general formula of FeCoNiVMoTixCry, where 0.05?x?0.2, 0.05?y?0.3, x and y are molar ratios. The radiation resistant high-entropy alloy has excellent irradiation resistance and is subject to radiation hardening saturation at high temperature (600° C.) in a condition of a high dose (1-3×1016 ions/cm2) of helium ion irradiation. A lattice constant of the high-entropy alloy decreases abnormally after irradiation. The high-entropy alloy has a radiation resistance far higher than that of a conventional alloy and has an excellent plasticity and specific strength. In an as-cast condition and at room temperature, a tensile break strength of the high-entropy alloy is higher than 580 MPa, an engineering strain (a tensile elongation) of the high-entropy alloy is greater than 30%.

Abstract: The present invention provides a radiation resistant high-entropy alloy and a preparation method thereof. A general formula of the radiation resistant high-entropy alloy is TiZrHfVMoTaxNby, where 0.05?x?0.25, 0.05?y?0.5, and x and y are molar ratios. The preparation method of the radiation resistant high-entropy alloy comprises the following steps: mixing Ti, Zr, Hf, V, Mo, Ta, and Nb in order, and conducting vacuum levitation induction melting or vacuum arc melting, to obtain the radiation resistant high-entropy alloy. The high-entropy alloy in the present invention has an excellent irradiation resistance, and does not suffer radiation hardening damage under simulated helium ion irradiation. When helium bubbles are of same sizes as those of conventional alloy, the bubble density of the high-entropy alloy is far lower than that of the conventional alloy, and the lattice constant thereof decreases abnormally after irradiation.

Abstract: An object of the present invention is to provide a process for continuously casting a molten metal which process suppresses the instability of the initial solidification and stably improves the lubrication and the surface properties of the cast metal, and an apparatus therefore, in the process for continuously casting a molten metal an alternating current is applied to an electromagnetic coil which is provided so that it surrounds a continuous casting mold wall or is embedded in the side wall of the mold, whereby an electromagnetic force is exerted on the molten metal poured into the mold which either oscillates in a constant mode or does not oscillate and is starting to be solidified the process of the present invention also comprises periodically changing the amplitude or waveform of the alternating current to be applied, and the apparatus of the present invention is used for the process.

Abstract: An object of the present invention is to provide a process for continuously casting a molten metal which process suppresses the instability of the initial solidification and stably improves the lubrication and the surface properties of the cast metal, and an apparatus therefor, in the process for continuously casting a molten metal an alternating current is applied to an electromagnetic coil which is provided so that it surrounds a continuous casting mold wall or is embedded in the side wall of the mold, whereby an electromagnetic force is exerted on the molten metal poured into the mold which either oscillates in a constant mode or does not oscillate and is starting to be solidified the process of the present invention also comprises periodically changing the amplitude or waveform of the alternating current to be applied, and the apparatus of the present invention is used for the process.