Evolution of deformation near the triple point of grain junctions in Sn-based solders during in situ tensile test

Deformation phenomena of both pure tin and 63Sn37Pb eutectic solder under different conditions were traced near the triple point of grain junctions by in situ observation. It was found that grain boundaries showed up at the caring position due to the boundary sliding for the lower tensile rate. Voids and cavities were observed along grain boundaries for pure tin and 63Sn37Pb solder, respectively. After aging, however, boundary behavior was limited to some extent to the increase in grain size, and the deformation mechanism was intragranular-dominated instead.