Grain boundary migration in Fe-3.5% Si bicrystals with [001] tilt boundaries

Grain boundary (GB) migration was studied on Fe-3.5% Si bicrystals with [001] tilt boundaries with different angles, using both the Sun-Bauer technique and the constant driving force method. For the Sun-Bauer geometry, experimentally observed and theoretically predicted shapes of the GB were compared. For calculation of the GB shape the drag effect of impurities was taken into account. The interface mobility was determined in the temperature range from 1217 to 1377 K. In situ observation of the fastest migrating boundary confirmed the results obtained by conventional methods, and also corroborated the linear relation between GB velocity and driving force. The activation enthalpy and the logarithm of the pre-exponential factor, as derived for the different types of tilt boundaries studied, are linearly related, i.e. comply with the compensation effect. The obtained results were in good accordance with literature data of grain boundary mobility in Fe-3% Si bicrystals. (C) 1998 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.