PI-8

Study of the Phase Equilibria in the Ag-Sn-In System at 280^OC

Vassilev Gueorgui P.¹, Dobrev Evgueni S.^1,2, Tedenac Jean-Claude²

¹University of Sofia, Faculty of Chemistry, 1 J. Bourchier Av., 1164 Sofia, Bulgaria,

²University of Montpellier II, LPMC, 34095 Montpellier, France

X-ray diffraction, DSC, SEM and metallographic studies were used to construct the isothermal section of the Ag-Sn-In system at 280^oC.  The microhardness of the z, a and e phases, were measured. The values are generally lower than those of the respective phases in the Ag-Sn-Zn system (FCC solid solutions, the phases and e phases).  The differences are 2 to 3 times higher for the (aAg) phase, 20% for the Mg type phases and 10% for the Cu₃Ti type phases.

The results for the coordinates of the ternary eutectics coincide with those of Korhonen and Kivilahti (X_Ag = 0.025, X_Sn = 0.475 and X_In=0.500 at 113^oC).

 The homogeneity ranges of the solid solutions as well of the intermetallic phases were determined. No proof for the existence of the ternary z| phase was found.