GRAIN-BOUNDARY MOBILITY DURING RECRYSTALLIZATION OF COPPER

Average grain boundary migration rates during recrystallization of col d-deformed copper were estimated from stereological measurements. In t he same material, the instantaneous driving forces for boundary migrat ion during recrystallization were calculated from calorimetric measure ments 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 linea r dependence was observed. The average mobility of grain boundaries mi grating during recrystallization of cold-worked copper at 121 degrees C was calculated to be 6.31 x 10-(10) (m(4) s(-1) MJ(-1)). This result was found to be consistent with single boundary, curvature-driven gra in boundary mobilities measured in copper at higher temperatures. It w as also demonstrated that the average grain boundary mobility was reas onably within the expectation (order of magnitude uncertainty) of the Turnbull single process model of boundary migration with a process aki n to grain boundary self-diffusivity as the rate-controlling atomic me chanism.