Thermodynamic properties and primary phase structures of ternary Cu_90-xSn_xSb₁₀ alloys investigated by differential scanning calorimetry and laser flash method

Ternary Cu-Sn-Sb alloys are a good candidate for solder materials without Pb element. Therefore, the knowledge of thermodynamic properties and phase transition characteristics of this alloy system is essential not only for the fundamental research but also for the industry applications. In this letter, we have measured the liquidus and solidus temperatures, enthalpy of fusion and thermal diffusivity for ternary Cu_90-xSn_xSb₁₀ alloys by differential scanning calorimetry (DSC) and laser flash methods, respectively. Moreover, the typical growth morphologies of various intermetallic compounds are characterized. It is found that the primary Cu₃Sn, Cu₆Sn₅, Cu₄Sn, Cu₃Sb and SnSb phases display faceted growth mode, and develop into long strips or large blocks. By contrast, the primary (Cu) phase forms by non-faceted way into very coarse dendrites.