Aspects of coarsening in eutectic Sn–Pb Original Research Article

The coarsening of Pb-rich αPb domains in eutectic Sn–Pb solder during isothermal annealing has been studied in some detail. The importance of anisotropy and of coalescence events and the occurrence of a dynamic scaling regime are discussed. Orientation imaging microscopy reveals the presence of the following two distinct crystallographic orientations between αPb and βSn lamellae in quenched eutectic Sn–Pb solder: [0 0 1]αPb∥[1 0 1]βSn and (0 1 0)αPb∥(1 1 1)βSn; [1 1 1]αPb∥[0 1 0]βSn and (1̄ 1 0)αPb∥(0 0 1)βSn. The domain size distribution function is found to approach a dynamic scaling regime and coalescence of domains is shown to be the dominant mechanism for the growth of domains larger than the mean domain size.