TY - JOUR
T1 - High-resolution TEM analysis of defect structures in mechanically milled, nanocrystalline Fe
AU - Murayama, M.
AU - Howe, J. M.
AU - Hidaka, H.
AU - Takaki, Setsuo
PY - 2003
Y1 - 2003
N2 - Grain interior and grain-boundary structures of mechanically milled ultrafine-grained iron powder were investigated with atomic resolution using high-resolution transmission electron microscopy (HRTEM), Grain boundaries in the powder appear wavy and irregular, with no amorphous or other unusual defect structures present. Diffraction analysis of HRTEM images indicates that elongated grains approximately 100nm long and 20 nm wide consist of several sub-grains along their length, each rotated by several degrees around a common «110» axis. The presence of partial disclination dipoles in the sub-grains was also observed by HRTEM. Such structures indicate that shear, fragmentation and rotation of grains several to tens of nanometers in diameter occurs during severe plastic deformation. A mechanism for the formation of an ultrafine-grained structure in mechanically milled Fe involving partial disclinations is proposed.
AB - Grain interior and grain-boundary structures of mechanically milled ultrafine-grained iron powder were investigated with atomic resolution using high-resolution transmission electron microscopy (HRTEM), Grain boundaries in the powder appear wavy and irregular, with no amorphous or other unusual defect structures present. Diffraction analysis of HRTEM images indicates that elongated grains approximately 100nm long and 20 nm wide consist of several sub-grains along their length, each rotated by several degrees around a common «110» axis. The presence of partial disclination dipoles in the sub-grains was also observed by HRTEM. Such structures indicate that shear, fragmentation and rotation of grains several to tens of nanometers in diameter occurs during severe plastic deformation. A mechanism for the formation of an ultrafine-grained structure in mechanically milled Fe involving partial disclinations is proposed.
UR - http://www.scopus.com/inward/record.url?scp=0038379837&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0038379837&partnerID=8YFLogxK
U2 - 10.2355/isijinternational.43.755
DO - 10.2355/isijinternational.43.755
M3 - Article
AN - SCOPUS:0038379837
VL - 43
SP - 755
EP - 760
JO - Transactions of the Iron and Steel Institute of Japan
JF - Transactions of the Iron and Steel Institute of Japan
SN - 0915-1559
IS - 5
ER -