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CN-122028638-A - Mg3Sb2-xBixMaterial and thermoelectric and mechanical property cooperative regulation and control method based on room temperature deformation technology

CN122028638ACN 122028638 ACN122028638 ACN 122028638ACN-122028638-A

Abstract

The application relates to the technical field of thermoelectric material preparation, in particular to a Mg 3 Sb 2‑x Bi x material and a thermoelectric and mechanical property cooperative regulation and control method based on a room temperature deformation technology, which comprises the steps of providing a massive Mg 3 Sb 2‑x Bi x thermoelectric material, wherein 0< x <2 >, doping the massive Mg 3 Sb 2‑ x Bi x thermoelectric material with anion doping elements and/or cation primary elements, carrying out compression deformation on the massive Mg 3 Sb 2‑x Bi x thermoelectric material at room temperature, carrying out annealing treatment on the massive Mg 3 Sb 2‑x Bi x thermoelectric material after compression deformation, introducing high-density microscopic defects (such as dislocation and twin crystals) through plastic deformation at room temperature, and combining a subsequent low-temperature annealing process to realize accurate regulation and control of defect types, namely selectively eliminating dislocation unfavorable to thermoelectric properties, and simultaneously keeping twin crystals which are helpful for improving thermoelectric and mechanical properties, thereby achieving cooperative optimization of thermoelectric properties and mechanical properties.

Inventors

  • MAO JUN
  • XU YAO
  • ZHANG TIANYU
  • ZHAO PENG
  • JIANG FENG
  • ZHANG QIAN
  • CAO FENG

Assignees

  • 哈尔滨工业大学(深圳)(哈尔滨工业大学深圳科技创新研究院)

Dates

Publication Date
20260512
Application Date
20260123

Claims (10)

  1. 1. A thermoelectric and mechanical property cooperative regulation and control method of Mg 3 Sb 2-x Bi x material based on room temperature deformation technology is characterized by comprising the following steps: Providing a bulk Mg 3 Sb 2-x Bi x thermoelectric raw material, wherein 0< x <2, wherein the Mg 3 Sb 2-x Bi x thermoelectric raw material comprises an anionic doping element and/or a cationic proto-element doping; Performing compression deformation on the massive Mg 3 Sb 2-x Bi x thermoelectric raw material at room temperature; And annealing the bulk Mg 3 Sb 2-x Bi x thermoelectric raw material after compression deformation to obtain the Mg 3 Sb 2-x Bi x material with synergistically improved thermoelectric and mechanical properties.
  2. 2. The method for synergistically controlling thermoelectric and mechanical properties of a Mg 3 Sb 2-x Bi x material based on room temperature deformation technology according to claim 1, wherein: The anion doping element is at least one of Te, se and S; the cation doping element is at least one of Sc, Y, la, pr, ce, ag, mn.
  3. 3. The method for synergistically controlling thermoelectric and mechanical properties of a Mg 3 Sb 2-x Bi x material according to claim 1, wherein the method for preparing a bulk Mg 3 Sb 2-x Bi x thermoelectric raw material is as follows: weighing the simple substance raw materials with the corresponding mass of each element; mixing the weighed simple substance raw materials, and performing ball milling to obtain metal powder under a protective atmosphere; And filling the metal powder into a mould, and sintering the metal powder into a block-shaped Mg 3 Sb 2-x Bi x thermoelectric raw material in a vacuum environment.
  4. 4. A method for synergistic regulation and control of thermoelectric and mechanical properties of Mg 3 Sb 2-x Bi x material based on room temperature deformation technology as claimed in claim 3, characterized in that the metal powder is sintered at 0.5-0.8 times the melting point temperature of the bulk Mg 3 Sb 2-x Bi x thermoelectric raw material.
  5. 5. The method for synergistically controlling thermoelectric and mechanical properties of a Mg 3 Sb 2-x Bi x material based on a room temperature deformation technology as claimed in claim 4, wherein the sintering method is spark plasma sintering, and the sintering time is 2-5min.
  6. 6. The method for synergistically controlling thermoelectric and mechanical properties of a Mg 3 Sb 2-x Bi x material based on room temperature deformation technology as claimed in claim 3, wherein the ball milling time is 6-10 hours, and the granularity of the metal powder is 5-20 μm.
  7. 7. The method for synergistically controlling thermoelectric and mechanical properties of Mg 3 Sb 2-x Bi x material based on room temperature deformation technology as claimed in claim 1, wherein x is more than or equal to 0.45 and less than or equal to 1.55.
  8. 8. The method for synergistically regulating and controlling thermoelectric and mechanical properties of a Mg 3 Sb 2-x Bi x material based on a room temperature deformation technology according to claim 1, wherein the strain amount of the bulk Mg 3 Sb 2-x Bi x thermoelectric raw material after compression deformation is 10% -15%.
  9. 9. The method for synergistically controlling thermoelectric and mechanical properties of a Mg 3 Sb 2-x Bi x material based on room temperature deformation technology as claimed in claim 1, wherein the annealing temperature is 473-773k and the annealing time is 30-120 minutes.
  10. 10. A Mg 3 Sb 2-x Bi x material as claimed in any one of claims 1 to 9, and the Mg 3 Sb 2-x Bi x material is prepared by a method for synergistically controlling thermoelectric and mechanical properties based on room temperature deformation technology.

Description

Mg 3Sb2-xBix material and thermoelectric and mechanical property cooperative regulation and control method based on room temperature deformation technology Technical Field The application relates to the technical field of thermoelectric material preparation, in particular to a Mg 3Sb2-xBix material and a thermoelectric and mechanical property cooperative regulation and control method based on a room temperature deformation technology. Background Thermoelectric materials are functional materials capable of realizing direct conversion of heat energy and electric energy, and the physical bases of the thermoelectric materials are Seebeck effect (heat energy-electric energy) and Peltier effect (electric energy-heat energy). The characteristics enable the thermoelectric technology to have unique application value in the fields of waste heat recovery power generation, solid refrigeration, high-precision temperature control and the like. The core indicator for measuring the energy conversion efficiency of a thermoelectric material is a dimensionless thermoelectric figure of merit (zT), defined as zt= (S 2 T)/ρκ, where S is the seebeck coefficient, ρ is the electrical resistivity, T is the absolute temperature, and κ is the thermal conductivity. Thus, the key to increasing zT value is to synergistically optimize the electrical transport properties (increasing power factor pf=s 2/p) and the thermal transport properties (decreasing thermal conductivity κ). At present, through strategies such as element doping, alloying, energy band engineering, nano structuring and the like, remarkable progress is made in optimizing electroacoustic transport characteristics of materials and improving zT values. However, in the industrial application scenario, the thermoelectric material device also needs to bear the test of complex working conditions such as mechanical processing load, long-term service thermal stress and the like. If the mechanical properties (such as strength, toughness and processability) of the material are insufficient, the device preparation yield is low, the service reliability is reduced and the service life is shortened, so that the large-scale commercial application of the material is severely restricted. The existing researches respectively prove that the mechanical property can be effectively enhanced through defect engineering (such as dislocation introduction and twin crystal introduction), the electric transport property can be regulated and controlled through strain engineering, but the two approaches are not integrated, and a set of integrated process schemes capable of synchronously optimizing the thermoelectric and mechanical properties is lacked. On the specific material system level, the Bi 2Te3 -based material is the only thermoelectric system for realizing large-scale commercial application at present, but the Bi 2Te3 -based material has intrinsic brittleness, so that the precision machining difficulty is high, the device integration reliability is poor, the cost of a key element Te is high, and the application of the Bi 2Te3 -based material in wider scenes is limited. In recent years, mg 3Sb2-xBix -based thermoelectric materials have been the hot spot of research for new generation thermoelectric materials because they exhibit excellent thermoelectric properties (zT value comparable to Bi 2Te3 -based materials) in a temperature range near room temperature, are rich in the amount of raw materials (Mg) used, and are low in cost, and particularly, they have excellent room temperature plastic deformation ability (strain at break can reach 30% or more). The unique room temperature plasticity of the material brings remarkable industrial advantages to the material. Firstly, the risk of material breakage in the preparation process is low, the yield is improved, secondly, high-density microscopic defects can be introduced through plastic deformation without high-temperature and high-pressure environment, more possibility is provided for performance regulation, thirdly, the process flow is simplified, and the energy consumption is reduced. Therefore, based on the characteristics of the Mg 3Sb2-xBix material, development of an advanced process capable of synergistically regulating and controlling the thermoelectric performance and the mechanical performance of the material is of great significance for promoting the large-scale application of the high-performance thermoelectric material. The existing typical technical scheme generally comprises the following steps of weighing raw materials according to stoichiometric ratio, preparing alloy powder through high-energy ball milling, and obtaining a compact block material by adopting a spark plasma sintering technology. The subsequent treatment process mainly comprises annealing treatment, which is performed under vacuum or inert atmosphere, aims to eliminate sintering internal stress and accurately adjust carrier concentration so as to optimize electric condu