Measurements of grain boundary mobility in aluminium by in-situ SEM experiments

A combination of in-situ annealing and electron backscatter diffraction in the SEM has been used to measure the velocity of high angle grain boundaries during the recrystallization of a deformed single-phase AI-Si alloy. It is found that the boundary velocity is directly proportional to the driving pressure and that the activation energy for the process over all the conditions investigated is similar to that of self diffusion in aluminium. In agreement with previous work it is found that tilt boundaries of 40 +/- 10 degrees with misorientation axes within +/- 10 degrees of < 111 > have a larger mobility than other high angle boundaries. The mobility maximum is very much broader than is found during curvature-driven grain growth, suggesting that the process of boundary migration during recrystallization may differ from that during curvature driven grain growth.