A phenomenological constitutive model for type SN62 solder wire

A phenomenological constitutive model that simulates the uniform deformation of type SN62 solder wire under uniaxial monotonic creep tensile and stress relaxation loading is described. The model relates the flow stress of solder to the strain rate in a simple manner. Tensile tests, creep tests, and stress relaxation tests were performed, and the results are compared with the results obtained with the model. The sense and magnitude of the model´s fit to the creep data are inconsistent, suggesting that nonuniform deformation or random errors in the experiment are the source of much of the error. The model frequently underpredicts the stress level in relaxation tests. This error could be due to high stress machine compliance or the presence of a threshold stress for plastic deformation