Abstract
Ag-Pb-Te is an important system in thermoelectric applications. Various Ag-Pb-Te alloys are prepared and their microstructures are examined. The liquidus projection of ternary Ag-Pb-Te system is determined both by experimental investigations and Calphad calculations, and the results are in good agreement. There are eight primary solidification phases, Ag, γ-Ag 2 Te, β-Ag 2 Te, Ag 1.9 Te, Ag 5 Te 3 , Te, PbTe and Pb, including a miscibility gap extended from the Ag-Te side. A ternary-eutectic reaction, L = PbTe + Te + Ag 5 Te 3 , was determined with a liquid composition of Ag-4.3at%Pb-62.6at%Te at 337 C. A nanoscale microstructure containing a dotted PbTe and a lamellar matrix of Ag 5 Te 3 and Te phases results from the ternary eutectic reaction. The solidification paths of selective ternary Ag-Pb-Te alloys are calculated using the Scheil model with the optimized interaction parameters obtained in this study, and the results are consistent with the experimental observations. © 2013 Elsevier B.V. All rights reserved.