Room temperature creep behavior of free-standing Cu films with bimodal grain size distribution

The creep behavior of free-standing Cu films with bimodal grain size distribution was investigated at room temperature. It is found that the higher loading rate, the greater the primary creep strain rate and the smaller the steady-state creep strain rate. This unique creep behavior was explained by considering the competition between dislocation activities and dislocation stress fields. Given the grain size distribution, a modified phase-mixture model is proposed to predict the scaling behavior of creep rate and applied stress.