Micromechanical modeling of the cyclic behavior of Sn-0.7Cu solder based on micromechanical polycrystalline approach

In the current research, a small strain multi-scale constitutive model based on self-consistent method is developed to describe the rate- and temperature-dependent behavior of cyclic deformed Sn-0.7Cu solder. A modification is proposed on the traditional elastic plastic self-consistent (EPSC) model to capture the elasto-viscoplastic behavior of Sn-0.7Cu solder. A modified Voce hardening law is proposed to describe the decrease of hardening rate with the increase of the accumulated shear strain. The developed model is compiled into finite element analysis to predict the macroscopic behavior of polycrystalline materials. The prediction is verified with the Taylor factor and the experimental data of Sn-0.7Cu solder. The reasonable accurate prediction shows that the model is effective in simulating the cyclic behavior of Sn-0.7Cu solder at different temperatures and strain rates.