Targeted Use of SPS Method for Improvement of Thermoelectrics
Targeted Use of SPS Method for Improvement of Thermoelectrics
复制标题
有针对性地使用 SPS 方法改进热电性能
DOI：
10.4028/www.scientific.net/ast.93.168
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
D. Pshenay
中科院分区：
文献类型：
--
作者：
L. Bulat;I. A. Nefedova;D. Pshenay
火花等离子体烧结（SPS）的应用可以提高体纳米热电体的热电优值Z，但SPS工艺所需的参数只能凭经验确定。在本研究中，应用有限单元法研究发生在烧结颗粒体积和边界上的电和热过程。选取含有“截锥-板”接触的烧结试样结构单元作为几何模型。利用能量平衡方程和电流连续性方程，得到了基于碲化铋的固溶体中温度随电流振幅、开关时间比和冲击持续时间的分布。在一定条件下，非线性和非局部过程开始出现。将计算得到的不同烧结条件下的温度分布与经验定义的实验参数进行了比较，得出了提高z值的最佳工艺条件。本文的方法不仅适用于热电材料，还可用于不同应用场合SPS制造工艺的管理。
Use of spark plasma sintering (SPS) allows improving thermoelectric figure of merit Z of bulk nanothermoelectrics but required parameters of SPS process for achievement of best Z can be defined only empirically. In the present study the finite elements method for investigation of electric and thermal processes which occur in volume and on boundaries of sintering particles is applied. As a geometrical model a structural cell of a sintered sample, containing contact “a truncated cone - a plate” has been chosen. Temperature distributions in the volume of a sample depending on amplitude, on-off time ratio and duration of impact of the electric current has been obtained for solid solution based on bismuth telluride using the energy balance equation and the equation of electric current continuity. Under certain conditions nonlinear and nonlocal processes start to arise. The calculated temperature distributions at different sintering conditions were comparing with empirically defined experimental parameters that lead to improved value of Z. The comparison allows formulating recommendations to achieve best conditions of SPS process for increase of Z. The present method can be used for management of SPS fabrication process for different application, not only for thermoelectrics.