Abstract
In order to improve the creep resistance of Sn based solder alloys, it is effective to strengthen the primary β-Sn phase by solidsolution hardening through solute atoms. Focusing on Ga, which has high solid solubility limit over a wide range of temperatures, the effect of Ga addition on the creep properties of Sn was investigated. The stress exponent and activation energy demonstrated that the creep deformation mechanism of Sn was a climb-controlled dislocation creep controlled by pipe diffusion. Moreover, assuming no temperature dependence of the segregation of Ga to stacking faults, the creep deformation mechanisms of Sn-Ga alloys were considered to be a climb-controlled dislocation creep controlled by pipe diffusion. A comparison of the creep resistance of Sn-based binary alloys, such as Sn-Ga, Sn-Bi, Sn-Sb, and Sn-Zn, revealed that Ga was the most effective element for improving the creep resistance of Sn, followed by Bi, Zn, and Sb.
