Grain boundary mobility during recrystallization of copper

Abstract

Average grain boundary migration rates during recrystallization of cold-deformed copper were estimated from stereological measurements. In the same material, the instantaneous driving forces for boundary migration during recrystallization were calculated from calorimetric measurements of the release of the stored energy of cold work. The migration rate dependence on driving force was analyzed in the context of grain boundary migration rate theory, and within experimental error, a linear dependence was observed. The average mobility of grain boundaries migrating during recrystallization of cold-worked copper at 121°C was calculated to be 6.31×10−10 (m4 s−1 MJ−1). This result was found to be consistent with single boundary, curvature-driven grain boundary mobilities measured in copper at higher temperatures. It was also demonstrated that the average grain boundary mobility was reasonably within the expectation (order of magnitude uncertainty) of the Turnbull single process model of boundary migration with a process akin to grain boundary self-diffusivity as the rate-controlling atomic mechanism.