The effect of Cu content on the microstructure and the vibration deformation mechanisms of a potential lead-free solder, Sn-xCu (x=0.3, 0.6, 1.3, 1.7 wt.%), are examined in this study. The results show that proeutectic Sn-rich phase decreased, while Cu6Sn5 intermetallic compounds increased with increasing the Cu content. For the specimens with high Cu content (1.3Cu and 1.7Cu), hard massive Cu6Sn5 existed mostly amongst the proeutectic Sn-rich phase dendrites, increasing the tensile strength. Under a constant vibration force and constant initial-deflection testing, the 0.6Cu specimen with a higher damping capacity was able to absorb more vibration energy and thus possessed a greater vibration fracture resistance. In addition, the lamellar-deformed structures (LDS) and Cu 6Sn5 were able to increase the crack tortuosity, which in turn increased the crack propagation resistance.
All Science Journal Classification (ASJC) codes