A method for preparing an oxygen-free passivated titanium or titanium-alloy powder product by means of gas-solid fluidization is provided. The new method includes placing the metal halide and the titanium powder which meet formula requirements into a gasifier and a fluidized bed reactor respectively; heating the gasifier to gasify the metal halide, and introducing dry argon and halide gas into the fluidized bed reactor; opening the fluidized bed, heating the fluidized bed, fluidizing the titanium powder after the introduction of the argon and the metal halide gas, and cooling the product to obtain the titanium powder subjected to oxygen-free passivation using metal chloride; molding the oxygen-free passivated titanium powder into a green body with powder metallurgy technology; and sintering the green body in vacuum or argon atmosphere according to the molding technology, and after temperature rise treatment, performing a densification sintering operation to obtain a high-performance titanium product component.

A method for preparing an oxygen-free passivated titanium or titanium-alloy powder product by means of gas-solid fluidization is provided. The new method includes placing the metal halide and the titanium powder which meet formula requirements into a gasifier and a fluidized bed reactor respectively; heating the gasifier to gasify the metal halide, and introducing dry argon and halide gas into the fluidized bed reactor; opening the fluidized bed, heating the fluidized bed, fluidizing the titanium powder after the introduction of the argon and the metal halide gas, and cooling the product to obtain the titanium powder subjected to oxygen-free passivation using metal chloride; molding the oxygen-free passivated titanium powder into a green body with powder metallurgy technology; and sintering the green body in vacuum or argon atmosphere according to the molding technology, and after temperature rise treatment, performing a densification sintering operation to obtain a high-performance titanium product component.

A method for preparing an oxygen-free passivated titanium or titanium-alloy powder product by means of gas-solid fluidization is provided. The new method includes placing the metal halide and the titanium powder which meet formula requirements into a gasifier and a fluidized bed reactor respectively; heating the gasifier to gasify the metal halide, and introducing dry argon and halide gas into the fluidized bed reactor; opening the fluidized bed, heating the fluidized bed, fluidizing the titanium powder after the introduction of the argon and the metal halide gas, and cooling the product to obtain the titanium powder subjected to oxygen-free passivation using metal chloride; molding the oxygen-free passivated titanium powder into a green body with powder metallurgy technology; and sintering the green body in vacuum or argon atmosphere according to the molding technology, and after temperature rise treatment, performing a densification sintering operation to obtain a high-performance titanium product component.

Methods for the manufacture of fine metal powders from metal carboxylate compounds such as metal oxalate compounds. The method includes decomposing particulates of the metal oxalate compound by heating to a decomposition temperature in the presence of a dilute hydrogen gas to decompose the metal oxalate compound, and forming a fine metal powder by heating to a higher refining temperature to remove contaminants from the metal powder. The method may include the conversion of a non-oxalate metal compound to a hydrated metal oxalate and the dehydration of the hydrated metal oxalate before decomposition to the metal. The method is applicable to the production of a wide variety of metals, and is particularly applicable to the production of rare earth metals of high purity and fine particle size.

Methods for the manufacture of fine metal powders from metal carboxylate compounds such as metal oxalate compounds. The method includes decomposing particulates of the metal oxalate compound by heating to a decomposition temperature in the presence of a dilute hydrogen gas to decompose the metal oxalate compound, and forming a fine metal powder by heating to a higher refining temperature to remove contaminants from the metal powder. The method may include the conversion of a non-oxalate metal compound to a hydrated metal oxalate and the dehydration of the hydrated metal oxalate before decomposition to the metal. The method is applicable to the production of a wide variety of metals, and is particularly applicable to the production of rare earth metals of high purity and fine particle size.

There is a problem that when a silver powder sintering paste that is substantially free from resin is used, an organic solvent used as a dispersion medium bleeds, which results in contamination and wire bonding defects. In order to solve the problem, provided is a metal powder sintering paste that contains, as a principal component, silver particles having an average particle diameter (a median diameter) of 0.3 μm to 5 μm and further contains an anionic surfactant but is substantially free from resin.

There is a problem that when a silver powder sintering paste that is substantially free from resin is used, an organic solvent used as a dispersion medium bleeds, which results in contamination and wire bonding defects. In order to solve the problem, provided is a metal powder sintering paste that contains, as a principal component, silver particles having an average particle diameter (a median diameter) of 0.3 μm to 5 μm and further contains an anionic surfactant but is substantially free from resin.

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.

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.

Disclosed is a method for preparing a metal-carbon composite. The method includes synthesizing a planarized ligand compound via planarization-modification of a polyphenol-based ligand compound; synthesizing a metal-organic composite via hydrothermal synthesis of a mixed solution of the planarized ligand compound and metal ions; drying the metal-organic composite to prepare precursor powders; and carbonizing the precursor powders.