Phase Equilibria in the Cu-Sn-Sb Ternary System

The phase equilibria in the Cu-Sn-Sb ternary system were investigated by means of electron-probe microanalysis and x-ray diffraction. Firstly, ternary solubilities of η-Cu6Sn5, δ-Cu41Sn11, Cu11Sb3, ε-Cu3Sb and η-Cu2Sb, were less than 7 at.% Sb or Sn at 400 °C. Besides, an re-stabilized ternary solubility, Cu6(Sn,Sb)5, was detected with a homogeneity range of Cu: 52.9-53.3 at.%, Sn: 28.4-30.9 at.%, and Sb: 15.8-18.7 at.%. Its origin was traced back to high-temperature stabilization of the binary η-Cu6Sn5 phase. Thirdly, the metastable phase, Cu11Sb3, was observed at 400 °C in the Cu-Sn-Sb ternary system; On raising the temperature to 500 °C, the ε-Cu3Sn phase still retained a large solubility for Sb, at ~ 16 at.%, while the ε-Cu3Sb was replaced by β-Cu3Sb with a dual-cornered large homogeneity range. Similarly, a ternary homogeneity range of Cu: 83.8-84.9 at.%, Sn: 2.6-6.2 at.%, and Sb: 9-12.5 at.%, was found and deduced to be the high temperature stabilization phase of γ-Cu11(Sb,Sn)2 at 500 °C.