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

The tensile and creep deformation of a series of high lead solders with 2% to 10% tin over a temperature range of 0 degrees C to 100 degrees C is discussed. 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. It is found that the mechanical behavior during thermal cycling tests depends on cycle frequency and temperature range in a manner determined by the evolution of the precipitate microstructure. The tensile and creep test results reported are for simple, controlled thermal histories, which are not necessarily representative of cyclic conditions. It is apparent that the microstructure must be taken into account in evaluating the results of any plastic deformation experiments.<>