Low-cycle fatigue properties of eutectic solders at high temperatures

This paper details the deformation mechanism and low-cycle fatigue life of eutectic solder alloys at high temperature (around 0.8 T_m). Grain boundary sliding generally nucleates a wedge-type cavity that reduces the low-cycle fatigue life of metals. In this study, grain boundary sliding has promoted intergranular failure contributing to the reduction in fatigue life of Sn-Ag-Cu alloy. However, grain boundary sliding has exerted no deleterious effects on fatigue resistance of eutectic Pb-Sn and Bi-Sn alloys. The phase boundary sliding with very fine microstructure induces exceptional ductility in these alloys leading to superior low-cycle fatigue endurance for theses eutectic Pb-Sn and Bi-Sn alloys.