Indentation creep of lead-free Sn–9Zn and Sn–8Zn–3Bi solder alloys

Creep behavior of Sn–9%Zn and Sn–8%Zn–3%Bi solders together with Sn–37% Pb, as the material for comparison, was studied by indentation tests at room-temperature (T > 0.6Tm) in order to evaluate the correspondence of the creep results obtained by different methods of analysis, and to evaluate the effect of Bi on the creep response of the eutectic Sn–9%Zn alloy. Stress exponent values determined through these methods were in good agreement. The better creep resistance of the ternary alloy is attributed to solid solutioning effect and precipitation of Bi in the Sn matrix. Both tin-based alloys showed creep resistances higher than that of the Sn–37% Pb alloy.