Preparation method of SiGe alloy thermoelectric material

Abstract

The invention relates to a preparation method of a SiGe alloy thermoelectric material. The preparation method of the SiGe alloy thermoelectric material is characterized by comprising the following steps of: (1) weighing high-purity Si blocks, high-purity Ge blocks and dopants as raw materials according to a chemical formula Si80Ge20X0-3, wherein X in the chemical formula stands for elements of the dopants; mixing the high-purity Si blocks, the high-purity Ge blocks and the dopants, then melting for 2 to 3 times with 30s each time in an argon arc melting furnace to obtain an alloy block body; (2) grinding and crushing the alloy block body obtained in the step (1), then ball-milling for 1 to 2h in a ball mill by taking alcohol as a ball-milling process controlling agent, and drying to obtain alloy powder; and (3) carrying out electro-discharging plasma sintering on the alloy powder obtained in the step (2) to obtain compact and blocky SiGe alloy thermoelectric material. The invention has the advantages of simple process, short preparation time, easily-controlled process parameters and high performance of the prepared material.

Description

technical field [0001] The invention belongs to the technical field of new energy materials, and in particular relates to a preparation method of a SiGe alloy thermoelectric material. Background technique [0002] Thermoelectric power generation is a fully static direct power generation method that uses thermoelectric conversion materials to directly convert heat energy into electrical energy. It has the advantages of compact structure, reliable performance, no noise during operation, no wear, no leakage, and flexible movement. , The field of microelectronics plays an important role. With the increasingly prominent energy and environmental issues, thermoelectric batteries, as a green energy technology with a wide range of adaptability and environmental protection, have attracted more and more attention. [0003] SiGe alloy is currently a relatively mature high-temperature thermoelectric material. It is used at high temperatures above 700K. At 1200K, its dimensionless thermo...

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Problems solved by technology

Although the zone melting method and mechanical alloying method can prepare materials with uniform components, the preparation cycle is long and the energy consumption is large.

In the SiGe alloy phase diagram, the solid-liquid phase line separation is relatively large and segregation is likely to occur, resulting in Si-rich and Ge-rich regions in the material, and because the mutual diffusion rate between Si and Ge atoms is very small, it is not easy to make them uniform by annealing.

Traditional powder metallurgy methods generally obtain alloy blocks by melting Si and Ge elements for a long time, but long-time melting can easily lead to volatilization of doping elements, such as N-type doping element P is very volatile, so it is necessary to find a suitable melting methods and conditions

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