Temperature effect on rolling behavior of nano-twinned copper

The effect of temperature on the rolling behavior of an ultrafine-grained Cu with nano-scale twins is reported. Rolling the nano-twinned Cu at liquid nitrogen temperature (LNT) led to a slight drop in hardness with an obvious thickening of twins, while rolling at room temperature (RT) resulted in obvious hardening without change in twin thickness. The strengthening mechanism via dislocation–twin boundary interactions dominates the rolling-induced hardening at RT, and the twinning partial activities are responsible for the de-twinning and softening in rolling at LNT.