In order to examine the grain-boundary migration mechanism, two high purity Fe-3wt%Si bicrystals were produced.One has a (114)Σ9 coincidence boundary, and the other has a random boundary. In-situ observation of grain-boundary migration was conducted by synchrotron X-radiation dynamic topography.
It was found that macroscopic grain-boundary migration was recognised at the temperature above 1170K. From the results of isothermal annealing(12701320K), it was clarified that the mobility of Σ9 coincidence boundary was higher than that of the random boundary.
