Tensile Properties of Sn-Bi Lead-Free Solder Alloys

Abstract

The Influence of alloy composition on tensile properties of Sn-Bi, Sn-Bi-Cu and Sn-Bi-Ni lead-free solder alloys were investigated. It is found that the elongation of Sn-Bi alloys depend on Bi content, and Sn-40wt% Bi alloy has the highest elongation. The addition of Cu and Ni improves the ductility of Sn 35-45wt% Bi alloys. The fine microstructure of Sn-Bi-Cu or Ni alloys have an effect on the ductility of Sn-Bi based alloys. The elongation increases with decreasing strain rate and increasing temperature. Cu and Ni added to Sn-Bi alloy showed the super plasticity behavior at low strain rate and high temperature (more than 333 K). Moreover, strain rate sensitivity ‘m’ increases with temperature.