GRAIN-BOUNDARY MIGRATION IN FE-3.5-PERCENT SI BICRYSTALS WITH [001] TILT BOUNDARIES

Grain boundary (GB) migration was studied on Fe-3.5% Si bicrystals wit h [001] tilt boundaries with different angles, using both the Sun-Baue r technique and the constant driving force method. For the Sun-Bauer g eometry, 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 dete rmined in the temperature range from 1217 to 1377 K. In situ observati on of the fastest migrating boundary confirmed the results obtained by conventional methods, and also corroborated the linear relation betwe en GB velocity and driving force. The activation enthalpy and the loga rithm of the pre-exponential factor, as derived for the different type s of tilt boundaries studied, are linearly related, i.e. comply with t he compensation effect. The obtained results were in good accordance w ith literature data of grain boundary mobility in Fe-3% Si bicrystals. (C) 1998 Acta Metallurgica Inc. Published by Elsevier Science Ltd. Al l rights reserved.