Creep and tensile behavior of lead-rich lead-tin solder alloys

The authors report on the tensile and creep deformation of a series of high-lead solders with 0 to 10% tin, over a temperature range of 0 degrees C to 10 degrees C. In these alloys, the yield strength is strongly influenced by the precipitation of the tin phase, which depends on temperature and tin content. The creep rupture behavior follows the Monkman-Grant relationship. The results are generally consistent with a power-low creep mechanism, controlled by dislocation-core diffusion. There is a clear trend to greater creep resistance (lower creep rate at a given stress and temperature) for alloys of higher tin concentration. It is concluded that the mechanical behavior during thermal cycling tests may depend on cycle frequency and temperature range in a manner determined by the evolution of the precipitate microstructure.<>