Influence of the addition of indium on the mechanical creep of Sn–3.5%Ag alloy

The present study was undertaken to investigate the influence of In metal addition to the eutectic Sn–3.5Ag binary composition for use as a Pb-free solder. The resulting properties of the binary system were extended to the Sn-based ternary systems Sn–Ag3.5–8In and Sn–Ag3.5–16In (where the composition are in wt.%) solder. Creep property and the microhardness tests of the Sn–Ag–In alloys were studied. The alloys showed the three creep stages. The activation energy for the steady state creep of the alloys was found to have an average value of 0.34 and 0.42 eV respectively. This might be characterizes by volume self diffusion as the controlling mechanism. On the other hand, the microstructures of the as cast alloys are reported as well. In addition the microstructure of the solder alloys before and after creep test was investigated.