Damping characteristics of Sn–3Ag–0.5Cu and Sn–37Pb solders studied by dynamic mechanical analysis

Sn–37Pb solder and pure Sn metal exhibit a conspicuous high-temperature damping background (HTDB) in low-frequency internal friction Q-1(T)Q-1(T) curves with activation energies, H, of HTDB being 0.43 and 0.98 eV, respectively. Sn–37Pb solder has a lamellar eutectic structure that can promote the diffusion-assisted climb of dislocations, resulting in lower H  . Sn–3Ag–0.5Cu solder shows no HTDB in Q-1(T)Q-1(T) curves since the formation of Cu6Sn5 and Ag3Sn intermetallics in the eutectic network band can impede dislocation motion.