Grain boundary migration in Fe-3mass%Si alloy bicrystals under a magnetic field

Abstract

Grain boundary migration under a magnetic field was studied using Fe-3mass%Si alloy bicrystals with (001)/Σ5 (φ=36°) and (001>/random (φ0=45°) tilt boundaries at temperatures between 1 223 K and 1 323 K. A capillarity method (Sun and Bauer method) was used to observe grain boundary migration. A 6 T magnetic field was applied parallel to the [100] direction, which is one of easy magnetization directions, in a grain whose area increases with occurring grain boundary migration. It was found that the application of a magnetic field observably increased the velocity of grain boundary migration for both bicrystals. The abrupt change in the velocity of grain boundary migration was observed at a critical capillary driving force irrespective of whether the magnetic field was applied. However, this critical driving force was decreased by application of a magnetic field, it was suggested that the magnetic field act as a driving force for grain boundary migration rather than increase its mobility. © 2010 ISIJ.