Abstract
The liquidus and solidus temperatures and enthalpy of fusion for Ag-Sn alloys are systematically measured within the whole composition range by differential scanning calorimetry (DSC). The measured enthalpy of fusion is related to Sn content by polynomial functions, which exhibit one maximum value at 52 wt%Sn and two minimum values around 21 wt%Sn and 96.5 wt%Sn, respectively. The liquidus slope, the solidification temperature interval, the solute partition coefficient and the entropy of fusion are calculated on the basis of the measured results. The undercoolability of those liquid Ag-Sn alloys solidifying with primary (Ag) solid solution phase is stronger than the other alloys with the preferential nucleation of ζ and ɛ intermetallic compounds. Morphological observations reveal that peritectic reactions can rarely be completed, and the peritectic microstructures are always composed of both primary and peritectic phases.
Highlights
In recent years, alloys solidifying with primary (Ag)-Sn alloys have aroused great scientific research interest because the Ag rich Ag-Sn alloys show excellent electronic conductivity and the Sn-rich Sn-Ag alloys are idea substitutes for lead-free solders [1,2,3,4,5]
All the measured values agree well with the published phase diagram [17], which verifies the accuracy of differential scanning calorimetry (DSC) measurement
The liquidus and solidus temperatures and enthalpy of fusion for binary Ag-Sn alloys in the whole composition range are determined by DSC method
Summary
Ag-Sn alloys have aroused great scientific research interest because the Ag rich Ag-Sn alloys show excellent electronic conductivity and the Sn-rich Sn-Ag alloys are idea substitutes for lead-free solders [1,2,3,4,5]. Many investigations reveal that the thermodynamic properties of liquid alloys and the final solid microstructures affect their performance [6,7,8,9,10,11,12,13]. One may neglect the fact that the undercoolability of liquid alloys relies on the alloy composition, and different alloys may be undercooled by varying degrees even under the same external condition. The enthalpy of fusion for Ag-Sn alloys within the entire composition range is measured by DSC method. The thermal characteristics and the final solidification microstructures of typical peritectic and eutectic Ag-Sn alloys are investigated on the basis of DSC calorimetric analyses
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
