Modeling Temperature Gradient Evolution of CoSb<SUB>3</SUB> Material for Thermoelectric Devices during Spark Plasma Sintering

Abstract

The temperature distribution and evolution of Mo/Ti/CoSb 3 materials used as thermoelectric couples of devices during spark plasma sintering were simulated by finite element method, and the results agree well with the die interior temperature measured by thermocouple. The sample and punches have higher temperature in whole sintering process, the highest temperature region is existed in CoSb 3 region, and the radial temperature gradient in CoSb 3 region is obvious. It was confirmed by experiments that the temperature gradient in sample results in non-uniform microstructure and thermal conductivity difference. The temperature gradient increases with decreasing thermal conductivity and increasing electrical resistivity of CoSb 3 -based compound, from the point of view of the thermal conductivity and electrical resistivity, respectively, the optimization method of the combined mechanical property and thermoelectric property of CoSb 3 -based compound was proposed.

Fundamental Aspects of Spark Plasma Sintering: II. Finite Element Analysis of Scalability

“…The conducted literature surveys indicate that spark plasma sintering (SPS) predictiveness and optimization depend on the availability of reliable process models, which are currently of high demand. Only few attempts have been undertaken to develop SPS‐specific constitutive models of powder consolidation; most of the modeling work on SPS has been dedicated to the numerical (predominantly, finite element) analyses of temperature and electric current distributions evolving in the tooling and specimens during SPS processing . Among the latter group of articles, some of the works assume specimen‐free SPS setups (these studies are useful for SPS tooling thermal expansion calibration), and some publications include stress analyses for SPS tooling and for powder specimens.…”

“… ¶ Among the 24 SPS finite element modeling studies, mentioned in the introductory section of this article, 12 works used ABAQUS ™ software, five works used COMSOL ™ software, and seven works utilized other finite element software codes. …”

Localized Overheating Phenomena and Optimization of Spark-Plasma Sintering Tooling Design

“…After the first works based on static analyses, some studies involving the implementation of the time evolution of material parameters, together with tracing the inhomogeneity of their spatial distributions, have been conducted [19,20,21,22,23,24,25]. Muñoz and Anselmi-Tamburini [29] established a discrete element model, which included such characteristics, focusing mainly on the specimen material inhomogeneities and on the non-uniformity of stress distributions.…”

“…Few constitutive models have been proposed, focusing on the influence of governing parameters of a thermal and non-thermal nature [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ], while the need for reliable numerical simulation approaches was becoming gradually more important. Some studies could consider only uncoupled physical aspects of SPS [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ], while, on the other hand, coupled modeling offers the opportunity of predicting the real outcomes of experimental procedures. During the recent years, a number of efforts have been dedicated to this objective.…”

Microstructure and Thermoelectric Properties of Bulk Cobalt Antimonide (CoSb3) Skutterudites Obtained by Pulse Plasma Sintering

“…The thermal conductivity, k, was calculated according to the formula k = aAEC p AEq, where C p is the theoretical heat capacity. 28 All measurements were performed over the temperature range of 323 K to 723 K. Figure 2 shows the XRD patterns of the CoSb 3 alloys after the first and second stage of heat treatment. The first heat treatment, conducted at 1173 K for 1 h followed by slow cooling, resulted in strong Bragg reflections of the CoSb 3 phase.…”