The present disclosure relates to an extrusion nozzle apparatus and a method for extruding a thermoelectric material using the extrusion nozzle apparatus. An extrusion nozzle apparatus according to one embodiment of the present disclosure comprises: an inlet introducing material; an outlet discharging the input material; and a discharge pipe formed in a multi-stage shape including a plurality of stages, wherein the input material is pressurized inside the discharge pipe and moves in a first direction from the inlet toward the outlet. The cross-sectional area of the plurality of stages in a direction perpendicular to the first direction progressively decreases from the inlet to the outlet. Accordingly, the thermoelectric performance of a thermoelectric material may be improved, and production cost and production time may be reduced.

The present disclosure relates to an extrusion nozzle apparatus and a method for extruding a thermoelectric material using the extrusion nozzle apparatus. An extrusion nozzle apparatus according to one embodiment of the present disclosure comprises: an inlet introducing material; an outlet discharging the input material; and a discharge pipe formed in a multi-stage shape including a plurality of stages, wherein the input material is pressurized inside the discharge pipe and moves in a first direction from the inlet toward the outlet. The cross-sectional area of the plurality of stages in a direction perpendicular to the first direction progressively decreases from the inlet to the outlet. Accordingly, the thermoelectric performance of a thermoelectric material may be improved, and production cost and production time may be reduced.

A method of producing anisotropic magnetic powders comprising obtaining a precipitate containing an element R, iron and lanthanum from a solution including R, iron and lanthanum, wherein R is at least one selected from the group consisting of Sc, Y, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm and Lu; obtaining an oxide containing R, iron and lanthanum from the precipitate; treating the oxide with a reducing gas to obtain a partial oxide; obtaining alloy particles by reduction diffusion of the partial oxide at a temperature in the range of 920° C. to 1200° C.; and nitriding the alloy particles to produce an anisotropic magnetic powder represented by the following general formula: R.sub.v-xFe.sub.(100-v-w-z)N.sub.wLa.sub.xW.sub.z, where 3≤v−x≤30, 5≤w≤15, 0.08≤x≤0.3, and 0≤z≤2.5.

A method of producing anisotropic magnetic powders comprising obtaining a precipitate containing an element R, iron and lanthanum from a solution including R, iron and lanthanum, wherein R is at least one selected from the group consisting of Sc, Y, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm and Lu; obtaining an oxide containing R, iron and lanthanum from the precipitate; treating the oxide with a reducing gas to obtain a partial oxide; obtaining alloy particles by reduction diffusion of the partial oxide at a temperature in the range of 920° C. to 1200° C.; and nitriding the alloy particles to produce an anisotropic magnetic powder represented by the following general formula: R.sub.v-xFe.sub.(100-v-w-z)N.sub.wLa.sub.xW.sub.z, where 3≤v−x≤30, 5≤w≤15, 0.08≤x≤0.3, and 0≤z≤2.5.

A method for heat treating metal alloy powder includes (a) introducing metal alloy powder to a chamber having a floor and a sidewall; (b) flowing a fluidizing gas through the floor and into the chamber to fluidize the metal alloy powder in the chamber; (c) flowing an additional gas through the sidewall into the chamber; and (d) heating the chamber to heat treat the metal alloy powder in the chamber. A system for heat treating metal alloy powder includes an inner chamber having a porous floor and a porous sidewall; an outer chamber, the inner chamber being inside of the outer chamber and defining an annular space between the outer chamber and the inner chamber, wherein the outer chamber and the inner chamber are inside a furnace; a source of fluidizing gas connected to the porous floor through the annular space; and a source of additional gas communicated with the porous sidewall through the annular space.

A method to achieve full densification and grain size control for sintering metal materials, wherein raw material powder is deagglomerated to obtain deagglomerated powder with dispersion. The deagglomerated powder is granulated by spray granulation. The granulated particles are processed by high-pressure die pressing and cold isostatic pressing. The powder compact is sintered by two-step pressureless sintering. The first step is to heat up the powder compact to a higher temperature and hold for a short time to obtain 75-85% theoretical density; the second step is to cool down powder compact to a lower temperature and hold for a long time. The two-step sintering can decrease the sintering temperature, so that the powder compact can be densified at a lower temperature. Thus, the obtained refractory metal product is densified, with ultrafine grains, uniform grain size distribution, and outstanding mechanical properties.

A method to achieve full densification and grain size control for sintering metal materials, wherein raw material powder is deagglomerated to obtain deagglomerated powder with dispersion. The deagglomerated powder is granulated by spray granulation. The granulated particles are processed by high-pressure die pressing and cold isostatic pressing. The powder compact is sintered by two-step pressureless sintering. The first step is to heat up the powder compact to a higher temperature and hold for a short time to obtain 75-85% theoretical density; the second step is to cool down powder compact to a lower temperature and hold for a long time. The two-step sintering can decrease the sintering temperature, so that the powder compact can be densified at a lower temperature. Thus, the obtained refractory metal product is densified, with ultrafine grains, uniform grain size distribution, and outstanding mechanical properties.

A method for producing agglomerated tantalum particles, comprising: a step for grinding secondary tantalum particles, which are obtained by reducing a tantalum salt, and adding water thereto to give a water-containing mass; a step for drying said water-containing mass to give a dry mass; a step for sieving said dry mass to give spherical particles; and a step for heating said spherical particles. A mixed tantalum powder comprising a mixture of agglomerated tantalum particles (X) with agglomerated tantalum particles (Y), wherein said agglomerated tantalum particles (X) show a cumulative percentage of particles with particle size of 3 μm or less of 5 mass % or less after 25 W ultrasonic radiation for 10 min, while said agglomerated tantalum particles (Y) show a cumulative percentage of particles with particle size of 3 μm or less of 10 mass % or more after 25 W ultrasonic radiation for 10 min.

A method for producing agglomerated tantalum particles, comprising: a step for grinding secondary tantalum particles, which are obtained by reducing a tantalum salt, and adding water thereto to give a water-containing mass; a step for drying said water-containing mass to give a dry mass; a step for sieving said dry mass to give spherical particles; and a step for heating said spherical particles. A mixed tantalum powder comprising a mixture of agglomerated tantalum particles (X) with agglomerated tantalum particles (Y), wherein said agglomerated tantalum particles (X) show a cumulative percentage of particles with particle size of 3 μm or less of 5 mass % or less after 25 W ultrasonic radiation for 10 min, while said agglomerated tantalum particles (Y) show a cumulative percentage of particles with particle size of 3 μm or less of 10 mass % or more after 25 W ultrasonic radiation for 10 min.

A preparation method for a silver-metal oxide electrical contact material, comprising: (1) mixing a silver-containing precursor solution with a metal oxide precursor solution; (2) reacting a reducing agent with the mixed solution to obtain silver powder coated with a metal oxide precursor; (3) heat treating the silver powder in a non-reducing atmosphere to obtain the silver-metal oxide electrical contact material. A preparation device for a silver-metal oxide electrical contact material, a silver-metal oxide electrical contact material prepared by the preparation method, and an electrical contact prepared by the silver-metal oxide electrical contact material. The electrical contact material prepared by the preparation method is at nanoscale, significantly prolonging electrical endurance of the electrical contact.