Abstract
Ternary Sn-In-Cu alloys are prepared and equilibrated at 250 °C for 2 to 20 weeks. The phases formed in these alloys are experimentally determined. The 250 °C Sn-In-Cu isothermal section is established according to the phase equilibrium information obtained in this study and that of the three constituent binary systems. It has eight single-phase regions, namely liquid, δ 1 -Cu 41 Sn 11 , ε-Cu 3 Sn, δ 2 -Cu 7 In 3 , η-(Cu 6 Sn 5 , Cu 2 In), Cu 11 In 9 , Cu 2 In 3 Sn, and α-(Cu) phases, 14 two-phase regions, and seven three-phase regions. In the Sn-In-Cu system at 250 °C, the η-Cu 6 Sn 5 and η-Cu 2 In phases form a continuous solid solution and the ternary Cu 2 In 3 Sn compound is observed. The δ 1 -Cu 41 Sn 11 phase is stabilized at 250 °C with the introduction of indium although it transforms into α-(Cu) and ε-Cu 3 Sn phases via a eutectoid reaction around 350 °C in the binary Sn-Cu system. Except for the Cu 11 In 9 phase and the Cu 2 In 3 Sn ternary compound, the other binary compounds all have significant indium and tin mutual solubilities. © 2009 Materials Research Society.