Metallurgical and Materials Transactions A

, Volume 41, Issue 3, pp 641–650

Microstructure Size Control through Cooling Rate in Thermoelectric PbTe-Sb2Te3 Composites

  • Teruyuki Ikeda
  • Vilupanur A. Ravi
  • G. Jeffrey Snyder
Article

DOI: 10.1007/s11661-009-0143-4

Cite this article as:
Ikeda, T., Ravi, V.A. & Jeffrey Snyder, G. Metall and Mat Trans A (2010) 41: 641. doi:10.1007/s11661-009-0143-4

Abstract

Microstructures of alloys with three compositions in the pseudobinary PbTe-Sb2Te3 system cast in copper molds using the injection molding technique were examined by scanning electron microscopy (SEM), energy-dispersive spectrometry, and X-ray diffraction (XRD). The microstructural length scales such as interlamellar spacing (ILS) and secondary dendrite arm spacing vary over two orders of magnitude, e.g., from 0.2 to 20 μm for SDAS in the hypereutectic alloy, depending on injection pressure, distance from surface, or thickness. The decrease in the microstructural length scale with the decrease in distance from the surface, thickness, and increase in injection pressure is attributed to an increase in the cooling rates estimated using the heat-transfer theory in solids. The difference in the injection pressures is represented as the difference in the heat-transfer coefficients.

Copyright information

© The Minerals, Metals & Materials Society and ASM International 2009

Authors and Affiliations

  • Teruyuki Ikeda
    • 1
    • 2
  • Vilupanur A. Ravi
    • 3
  • G. Jeffrey Snyder
    • 2
  1. 1.PRESTOJapan Science and Technology AgencySaitamaJapan
  2. 2.Materials Science DepartmentCalifornia Institute of TechnologyPasadenaUSA
  3. 3.Chemical and Materials Engineering DepartmentCalifornia State Polytechnic UniversityPomonaUSA