Mantle region accommodating two-dimensional grain boundary sliding in ODS ferritic steel

作者：Masuda Hiroshi^*; Tobe Hirobumi; Sato Eiichi; Sugino Yoshito; Ukai Shigeharu

来源：Philosophical Magazine Letters, 2015, 95(7): 359-366.

DOI：10.1080/09500839.2015.1067732

• superplasticity
• grain boundary sliding
• dislocations
• oxide-dispersion-strengthened (ODS) steel
• focused ion beam (FIB)
• core-mantle model

Two-dimensional grain-boundary sliding (GBS) was achieved microscopically in an oxide-dispersion-strengthened ferritic steel with an elongated and aligned grain structure, which was deformed perpendicular to the long axis. At the border between superplastic regions II and III, microscopic deformation was observed using sub-micron grids drawn on the material surface using a focused ion beam. GBS was accommodated by intragranular deformations in narrow areas around grain boundaries, which has been predicted by earlier researchers as characteristics of the core-mantle model. These observations suggest that dislocations slip only in the mantle regions around wavy boundaries to relax the stress concentration caused by GBS during superplasticity.

• 出版日期2015-7-3