The Effects of Solution Treatment and Room Temperature Ageing on Mechanical Properties of Sn-37wt%Bi and Sn-57wt%Bi

Sn Bi alloys have been considered as promising candidates for of a new generation of low-temperature soldering alloys. However, the microstructure of these alloys is subject to change during storage and service due to the high homologous temperatures. This work investigates the tensile strength and hardness of samples to investigate the effect of solution treatment and room temperature ageing. It was found that the hardness of both compositions declined throughout 25 weeks of room temperature ageing. Meanwhile, solution treatment led to higher initial hardness with a fast decline in hardness during room subsequent room temperature ageing. Solution treatment also led to better ductility at some lower strain rates with similar tensile strength as the as-cast samples.