Combined hot extrusion and spark plasma sintering method for producing highly textured thermoelectric Bi2Te3 alloys. Issue 8 (July 2020)

• Record Type: Journal Article
• Authors: Lim, Sang-Soon; Jung, Sung-Jin; Kim, Byung Kyu; Kim, Dong-Ik; Lee, Byeong-Hyeon; Won, Sung Ok; Shin, Joonchul; Park, Hyung-Ho; Kim, Seong Keun; Kim, Jin-Sang; Baek, Seung-Hyub
• Is Part Of: Journal of the European Ceramic Society. Volume 40:Issue 8(2020)
• Page Start: 3042
• Page End: 3048
• Publication Date: 2020-07
• Subjects: Thermoelectrics -- Bi2Te3 alloys -- Hot extrusion (HE) -- Spark plasma sintering (SPS); Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2020.03.008
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: Hot extrusion is a promising method for producing high-performance thermoelectric bismuth telluride alloys because of its ability to create textured microstructures. However, hot extrusion is less favourable for scaling-up because of temperature and strain gradients along the radial direction, and only <110> -textured thermoelectric legs can be obtained because of the fibre-like texture. We suggest a way to overcome these disadvantages by implementing an additional spark plasma sintering process on a stack of extrudates. Using this combined process, we demonstrate the fabrication of 12 × 15 × 13 mm 3 p-type (Bi0.2 Sb0.8 )2 Te3 samples from extrudates that had originally been 3 mm in diameter. The evolution of sheet-like texture revealed by SEM, XRD, and EBSD allows us to obtain both <110> - and <001> -textured thermoelectric legs from a single specimen that are desirable for low- and high-temperature applications, respectively. Our results demonstrate the combined method as an industry-friendly process for fabricating high-performance thermoelectric materials.