HPT production of large bulk skutterudites

Rogl, G and Ghosh, S and Renk, O and Yubuta, K and Grytsiv, A and Schafler, E and Zehetbauer, M and Mallik, RC and Bauer, E and Rogl, P (2021) HPT production of large bulk skutterudites. In: Journal of Alloys and Compounds, 854 .

PDF JOU_ALL_COM_854_2021...pdf - Published Version Restricted to Registered users only Download (4MB) | Request a copy

Abstract

This paper documents that consolidation and subsequent severe plastic deformation of commercial skutterudite powders via high pressure torsion (HPT) serves for an easy, fast, cheap and sustainable production method for excellent n-type skutterudite bulks, (Sm,Mm)0.15Co4Sb12, with high ZT values. Large cylindrical samples with 30 mm in diameter and 8 mm thickness (�55 g) were successfully prepared in one step. These large samples enabled for the first time to (i) study the influence of shear strain on the micro-structural, thermoelectric and mechanical properties by analysing specimens cut from various positions of the HPT disks and (ii) to evaluate these properties orientation sensitive. These investigations were supported by electron probe microanalyses, transmission electron microscopy as well as XPD full profile analyses, XPS, Raman and Hall measurements. Whilst the orientation dependence on the electrical and thermal conductivity is found to be rather weak, the applied shear strain has a pronounced influence, as with increasing strains the thermal conductivity was reduced to the targeted levels. This beneficial effect, however, is accompanied by a massive increase of the electrical resistivity. ZT values turned out to be rather homogeneous over the entire sample with ZT�1.3 at 850 K. © 2020 Elsevier B.V.

Item Type:	Journal Article
Publication:	Journal of Alloys and Compounds
Publisher:	Elsevier Ltd
Additional Information:	Copyright for this article belongs to.Elsevier Ltd
Keywords:	Nanostructured materials Powder metallurgy Mechanical properties Thermal expansion Thermoelectric High-pressure torsion
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	14 Mar 2021 06:49
Last Modified:	14 Mar 2021 06:49
URI:	http://eprints.iisc.ac.in/id/eprint/66800

Actions (login required)

View Item