F. Ren, E. D. Case, E. J. Timm, H. J. Schock

Hardness as a function of composition for n-type LAST thermoelectric material

Journal of Alloys and Compounds 455 (2008) 340-345

Compositional changes (alloying) in metals, ceramics and semiconductors lead to changes in microstructure and mechanical properties that range from subtle to dramatic. In particular, hardness measurements have been widely used to track changes in mechanical properties as a function of composition. In this study, composition dependence of the Vickers indentation hardness, H, is examined for 17 specimens that include 15 different n-type compositions within the quaternary chalcogenide family of LAST (lead-antimony-silver-tellurium) high-temperature thermoelectric materials. In addition, nanoindentation measurements were made on six of the 17 specimens that were indented via Vickers indentation. The H values obtained independently by the microindentation (Vickers indentation) and nanoindentation techniques agreed very well. In this study, relationships from the literature for the parabolic dependence of H on the single compositional variable x for pseudo binaries AB(1 - x)C(x) is successfully extended to describe the composition dependence of H for a true quaternary system. Possible implications of hardness change on fabrication and in-service reliability are also discussed. (c) 2007 Elsevier B.V. All rights reserved.

This article may also be available to you online

Cited Articles

1. Zajíčková L., Buršíková V., Peřina V., Macková A., Janča J.,
   Correlation Between SiOx Content and Properties of DLC : SiOx Films Prepared by PECVD,
   Surface and Coatings Technology 174 (2003) 281–285