Measurements of grain boundary mobility during recrystallization of a single-phase aluminium alloy

A combination of in situ annealing and electron backscattered diffraction i n the SEM has been used to determine the mobility of high angle grain bound aries in a deformed single-phase AI-Si alloy. It is found that the boundary velocity is directly proportional to the driving pressure and that the act ivation energy for boundary migration over all the conditions investigated is consistent with control by lattice diffusion of the solute. It is confir med that tilt boundaries of recrystallized grains misoriented by 40 +/- 10 degrees about axes within +/-10 degrees of [111] have an increased mobility compared to other high angle boundaries, whereas the mobilities of 40 degr ees[111] twist boundaries are similar to those of general high angle bounda ries. The mobility maximum for the 40 degrees[111] tilt boundaries is very broad, which is in contrast to the sharp mobility peaks reported for curvat ure-driven grain growth, and possible reasons for these differences are dis cussed. (C) 1999 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.